Patent Publication Number: US-2023159905-A1

Title: Xylanase Variants and Polynucleotides Encoding Same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 16/621,493, which was filed on Dec. 11, 2019, now granted U.S. Pat. No. 11,499,144 issued Nov. 15, 2022, which is a 35 U.S.C. 371 national application of international application no. PCT/EP2018/066606 filed Jun. 21, 2018, which claims priority or the benefit under 35 U.S.C. 119 of European application no. 17177304.7 filed Jun. 22, 2017, the contents of which are fully incorporated herein by reference. 
    
    
     REFERENCE TO A SEQUENCE LISTING 
     This application contains a Sequence Listing in computer readable form. The contents of the electronic sequence listing created on Jun. 21, 2018, named 14571-WO-PCT_ST25.txt and 20 KB in size, is hereby incorporated by reference in its entirety. 
     FIELD OF THE INVENTION 
     The present invention relates to xylanase variants, polynucleotides encoding the variants; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; compositions comprising the xylanase variants and methods of using the variants. 
     DESCRIPTION OF THE RELATED ART 
     Xylans are hemicelluloses found in all land plants (Popper and Tuohy, 2010 , Plant Physiology  153: 373-383). They are especially abundant in secondary cell walls and xylem cells. In grasses, with type II cell walls, glucurono arabinoxylans are the main hemicellulose and are present as soluble or insoluble dietary fiber in many grass based food and feed products. 
     Plant xylans have a β-1,4-linked xylopyranose backbone that can be substituted at the O2 or O3 position with arabinose, glucuronic acid and acetic acid in a species and tissue specific manner. The starch-rich seeds of the sub-family Panicoideae with economically important species such as corn,  Sorghum , rice and millet have special types of highly substituted xylans in their cell walls. Compared to wheat flour, wherein over 60% of the xylosyl units in the arabinoxylan backbone are unsubstituted. In corn kernel xylan, the corresponding percentage of unsubstituted backbone xylosyls is 20-30%, and in  Sorghum  it is 35-40% (Huismann et al., 2000 , Carbohydrate Polymers  42: 269-279). Furthermore, in corn and  Sorghum  the xylan side chains can be longer than a single arabinose or glucuronic acid substitution which is common in other xylans. This added side chain complexity is often due to L- and D-galactose and D-xylose sugars bound to the side chain arabinose or glucuronic acid. About every tenth arabinose in corn kernel xylan is also esterified with a ferulic acid and about every fourth xylose carries an acetylation (Agger et al., 2010 , J. Agric. Food Chem.  58: 6141-6148). All of these factors combined make the highly substituted xylans in corn and  Sorghum  resistant to degradation by traditional xylanases. 
     The known enzymes responsible for the hydrolysis of the xylan backbone are classified into enzyme families based on sequence similarity (cazy.org). The enzymes with mainly endo-xylanase activity have previously been described in Glycoside hydrolase family (GH) 5, 8, 10, 11, 30 and 98. The enzymes within a family share some characteristics such as 3D fold and they usually share the same reaction mechanism. Some GH families have narrow or mono-specific substrate specificities while other families have broad substrate specificities. 
     Commercially available GH10 and GH11 xylanases are often used to break down the xylose backbone of arabinoxylan. In animal feed this results in a degradation of the cereal cell wall with a subsequent improvement in nutrient release (starch and protein) encapsulated within the cells. Degradation of xylan also results in the formation of xylose oligomers that may be utilised for hind gut fermentation and therefore can help an animal to obtain more digestible energy. However, such xylanases are sensitive to side chain steric hindrance and whilst they are effective at degrading arabinoxylan from wheat, they are not very effective on the xylan found in the seeds of Poaceae species, such as corn or  Sorghum.    
     Corn is used around the world in animal feed and thus there is a need to discover new polypeptides having xylanase activity that are capable of breaking down the highly branched xylan backbone in the cell wall in order to release more xylose and other nutrients which are trapped inside the cell wall. 
     The present invention provides xylanase variants with improved properties compared to its parent. 
     SUMMARY OF THE INVENTION 
     The present invention relates to methods for obtaining a xylanase variant, comprising (a) introducing into a parent xylanase a substitution at one or more positions corresponding to positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 31, 32, 33, 34, 39, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 64, 65, 67, 68, 79, 82, 88, 90, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 127, 128,129, 131, 135, 143, 145, 146, 159, 160, 165, 168,176, 179, 181, 188, 191,194, 195, 196, 197, 205, 209, 212, 217, 218, 221, 224, 231, 235, 237, 238, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 338, 339, 340, 342, 343, 344, 345, 346, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1, wherein the xylanase variant has xylanase activity and has at least 70% sequence identity to SEQ ID NO: 1; and (b) recovering the xylanase variant. 
     The present invention further relates to xylanase variants as disclosed above; compositions, such as granules, animal feed additives, liquid formulations and animal feed; use of the xylanase in e.g. animal feed; processes of producing a fermentation product; methods for preparing a dough or a baked product; polynucleotides encoding the xylanase variant; recombinant host cells and methods of producing the xylanase variants. 
     Overview of Sequence Listing 
     SEQ ID NO: 1 is the amino acid sequence of a mature GH30 xylanase from  Bacillus subtilis.    
     SEQ ID NO: 2 is the amino acid sequence of a mature GH30 xylanase from  Bacillus amyloliquefaciens.    
     SEQ ID NO: 3 is the amino acid sequence of a mature GH30 xylanase from  Bacillus licheniformis.    
     SEQ ID NO: 4 is the amino acid sequence of a mature GH30 xylanase from  Bacillus subtilis.    
     SEQ ID NO: 5 is the amino acid sequence of a mature GH30 xylanase from  Paenibacillus pabuli.    
     SEQ ID NO: 6 is the amino acid sequence of a mature GH30 xylanase from  Bacillus amyloliquefaciens  HB-26. 
     Definitions 
     Xylanase: The term “xylanase” means a glucuronoarabinoxylan endo-1,4-beta-xylanase (E.C. 3.2.1.136) that catalyses the endohydrolysis of 1,4-beta-D-xylosyl links in some glucuronoarabinoxylans. Xylanase activity can be determined with 0.2% AZCL-glucuronoxylan as substrate in 0.01% TRITON® X-100 and 200 mM sodium phosphate pH 6 at 37° C. One unit of xylanase activity is defined as 1.0 μmole of azurine produced per minute at 37° C., pH 6 from 0.2% AZCL-glucuronoxylan as substrate in 200 mM sodium phosphate pH 6. 
     Allelic variant: The term “allelic variant” means any of two or more alternative forms of a gene occupying the same chromosomal locus. Allelic variation arises naturally through mutation, and may result in polymorphism within populations. Gene mutations can be silent (no change in the encoded polypeptide) or may encode polypeptides having altered amino acid sequences. An allelic variant of a polypeptide is a polypeptide encoded by an allelic variant of a gene. 
     Animal: The term “animal” refers to all animals except humans. Examples of animals are non-ruminants, and ruminants. Ruminant animals include, for example, animals such as sheep, goats, cattle, e.g., beef cattle, cows, and young calves, deer, yank, camel, llama and kangaroo. Non-ruminant animals include mono-gastric animals, e.g., pigs or swine (including, but not limited to, piglets, growing pigs, and sows); poultry such as turkeys, ducks and chicken (including but not limited to broiler chicks, layers); horses (including but not limited to hotbloods, coldbloods and warm bloods), young calves; fish (including but not limited to amberjack, arapaima, barb, bass, bluefish, bocachico, bream, bullhead, cachama, carp, catfish, catla, chanos, char, cichlid, cobia, cod, crappie, dorada, drum, eel, goby, goldfish, gourami, grouper, guapote, halibut, java, labeo, lai, loach, mackerel, milkfish, mojarra, mudfish, mullet, paco, pearlspot, pejerrey, perch, pike, pompano, roach, salmon, sampa, sauger, sea bass, seabream, shiner, sleeper, snakehead, snapper, snook, sole, spinefoot, sturgeon, sunfish, sweetfish, tench, terror, tilapia, trout, tuna, turbot, vendace, walleye and whitefish); and crustaceans (including but not limited to shrimps and prawns). 
     Animal feed: The term “animal feed” refers to any compound, preparation, or mixture suitable for, or intended for intake by an animal. Animal feed for a mono-gastric animal typically comprises concentrates as well as vitamins, minerals, enzymes, direct fed microbial, amino acids and/or other feed ingredients (such as in a premix) whereas animal feed for ruminants generally comprises forage (including roughage and silage) and may further comprise concentrates as well as vitamins, minerals, enzymes direct fed microbial, amino acid and/or other feed ingredients (such as in a premix). 
     Arabinoxylan-containing material: The term “Arabinoxylan-containing material” means any material containing arabinoxylan. Arabinoxylan is a hemicellulose found in both the primary and secondary cell walls of plants, including woods and cereal grains, consisting of copolymers of two pentose sugars, arabinose and xylose. The arabinoxylan chain contains a large number of 1,4-linked xylose units. Many xylose units are substituted with 2-, 3- or 2,3-substituted arabinose residues. 
     Examples of arabinoxylan-containing material are forage, roughage, seeds and grains (either whole or prepared by crushing, milling, etc from, e.g., corn, oats, rye, barley, wheat), trees or hard woods (such as poplar, willow,  eucalyptus , palm, maple, birch), bamboo, herbaceous and/or woody energy crops, agricultural food and feed crops, animal feed products, cassava peels, cocoa pods, sugar cane, sugar beet, locust bean pulp, vegetable or fruit pomaces, wood waste, bark, shavings, sawdust, wood pulp, pulping liquor, waste paper, cardboard, construction and demolition wood waste, industrial or municipal waste water solids or sludge, manure, by-product from brewing and/or fermentation processes, wet distillers grain, dried distillers grain, spent grain, vinasse and bagasse. 
     Forage as defined herein also includes roughage. Forage is fresh plant material such as hay and silage from forage plants, grass and other forage plants, grass and other forage plants, seaweed, sprouted grains and legumes, or any combination thereof. Examples of forage plants are Alfalfa (Lucerne), birdsfoot trefoil,  brassica  (e.g., kale, rapeseed (canola), rutabaga (swede), turnip), clover (e.g., alsike clover, red clover, subterranean clover, white clover), grass (e.g., Bermuda grass, brome, false oat grass, fescue, heath grass, meadow grasses,  miscanthus , orchard grass, ryegrass, switchgrass, Timothy-grass), corn (maize), hemp, millet, barley, oats, rye,  Sorghum , soybeans and wheat and vegetables such as beets. Crops suitable for ensilage are the ordinary grasses, clovers, alfalfa, vetches, oats, rye and maize. Forage further includes crop residues from grain production (such as corn stover; straw from wheat, barley, oat, rye and other grains); residues from vegetables like beet tops; residues from oilseed production like stems and leaves form soy beans, rapeseed and other legumes; and fractions from the refining of grains for animal or human consumption or from fuel production or other industries. 
     Roughage is generally dry plant material with high levels of fiber, such as fiber, bran, husks from seeds and grains and crop residues (such as stover, copra, straw, chaff, sugar beet waste). 
     Preferred sources of arabinoxylan-containing materials are forage, roughage, seeds and grains, sugar cane, sugar beet and wood pulp. 
     Body Weight Gain: The term “body weight gain” means an increase in live weight of an animal during a given period of time, e.g., the increase in weight from day 1 to day 21. 
     cDNA: The term “cDNA” means a DNA molecule that can be prepared by reverse transcription from a mature, spliced, mRNA molecule obtained from a eukaryotic or prokaryotic cell. cDNA lacks intron sequences that may be present in the corresponding genomic DNA. The initial, primary RNA transcript is a precursor to mRNA that is processed through a series of steps, including splicing, before appearing as mature spliced mRNA. 
     Coding sequence: The term “coding sequence” means a polynucleotide, which directly specifies the amino acid sequence of a variant. The boundaries of the coding sequence are generally determined by an open reading frame, which begins with a start codon such as ATG, GTG or TTG and ends with a stop codon such as TAA, TAG, or TGA. The coding sequence may be a genomic DNA, cDNA, synthetic DNA, or a combination thereof. 
     Control sequences: The term “control sequences” means nucleic acid sequences necessary for expression of a polynucleotide encoding a variant of the present invention. Each control sequence may be native (i.e., from the same gene) or foreign (i.e., from a different gene) to the polynucleotide encoding the variant or native or foreign to each other. Such control sequences include, but are not limited to, a leader, polyadenylation sequence, propeptide sequence, promoter, signal peptide sequence, and transcription terminator. At a minimum, the control sequences include a promoter, and transcriptional and translational stop signals. The control sequences may be provided with linkers for the purpose of introducing specific restriction sites facilitating ligation of the control sequences with the coding region of the polynucleotide encoding a variant. 
     Expression: The term “expression” includes any step involved in the production of a variant including, but not limited to, transcription, post-transcriptional modification, translation, post-translational modification, and secretion. 
     Expression vector: The term “expression vector” means a linear or circular DNA molecule that comprises a polynucleotide encoding a variant and is operably linked to control sequences that provide for its expression. 
     Feed Conversion Ratio: The term “feed conversion ratio” the amount of feed fed to an animal to increase the weight of the animal by a specified amount. An improved feed conversion ratio means a lower feed conversion ratio. By “lower feed conversion ratio” or “improved feed conversion ratio” it is meant that the use of a feed additive composition in feed results in a lower amount of feed being required to be fed to an animal to increase the weight of the animal by a specified amount compared to the amount of feed required to increase the weight of the animal by the same amount when the feed does not comprise said feed additive composition. 
     Feed efficiency: The term “feed efficiency” means the amount of weight gain per unit of feed when the animal is fed ad-libitum or a specified amount of food during a period of time. By “increased feed efficiency” it is meant that the use of a feed additive composition according the present invention in feed results in an increased weight gain per unit of feed intake compared with an animal fed without said feed additive composition being present. 
     Fragment: The term “fragment” means a polypeptide having one or more (e.g., several) amino acids absent from the amino and/or carboxyl terminus of a mature polypeptide; wherein the fragment has xylanase activity. In one aspect, a fragment comprises at least 330 amino acid residues, at least 350 amino acid residues, or at least 370 amino acid residues. 
     In one aspect, a fragment comprises at least 330 amino acid residues of SEQ ID NO: 1, at least 350 amino acid residues of SEQ ID NO: 1, or at least 370 amino acid residues of SEQ ID NO: 1. In one aspect, a fragment comprises at least 330 amino acid residues of SEQ ID NO: 2, at least 350 amino acid residues of SEQ ID NO: 2, or at least 370 amino acid residues of SEQ ID NO: 2. In one aspect, a fragment comprises at least 330 amino acid residues of SEQ ID NO: 3, at least 350 amino acid residues of SEQ ID NO: 3, or at least 370 amino acid residues of SEQ ID NO: 3. In one aspect, a fragment comprises at least 330 amino acid residues of SEQ ID NO: 4, at least 350 amino acid residues of SEQ ID NO: 4, or at least 370 amino acid residues of SEQ ID NO: 4. In one aspect, a fragment comprises at least 330 amino acid residues of SEQ ID NO: 5, at least 350 amino acid residues of SEQ ID NO: 5, or at least 370 amino acid residues of SEQ ID NO: 5. In one aspect, a fragment comprises at least 330 amino acid residues of SEQ ID NO: 6, at least 350 amino acid residues of SEQ ID NO: 6, or at least 370 amino acid residues of SEQ ID NO: 6. 
     Highly branched xylan: The term “highly branched xylan” means that more than 50% of xylosyl units in the arabinoxylan backbone are substituted. This is preferably calculated from linkage analysis as performed in Huismann et al. Carbohydrate Polymers, 2000, 42:269-279. 
     Host cell: The term “host cell” means any cell type that is susceptible to transformation, transfection, transduction, or the like with a nucleic acid construct or expression vector comprising a polynucleotide of the present invention. The term “host cell” encompasses any progeny of a parent cell that is not identical to the parent cell due to mutations that occur during replication. 
     Improved property: The term “improved property” means a characteristic associated with a variant that is improved compared to the parent. Such improved properties include, but are not limited to, catalytic efficiency, catalytic rate, chemical stability, oxidation stability, pH activity, pH stability, specific activity, stability under storage conditions, substrate binding, substrate cleavage, substrate specificity, substrate stability, surface properties, thermal activity, and thermostability. In an embodiment, the improved property is improved thermostability, and thermostability may be determined as described in Example 2 herein. 
     Isolated: The term “isolated” means a substance in a form or environment which does not occur in nature. Non-limiting examples of isolated substances include (1) any non-naturally occurring substance, (2) any substance including, but not limited to, any enzyme, variant, nucleic acid, protein, peptide or cofactor, that is at least partially removed from one or more or all of the naturally occurring constituents with which it is associated in nature; (3) any substance modified by the hand of man relative to that substance found in nature; or (4) any substance modified by increasing the amount of the substance relative to other components with which it is naturally associated (e.g., multiple copies of a gene encoding the substance; use of a stronger promoter than the promoter naturally associated with the gene encoding the substance). An isolated substance may be present in a fermentation broth sample. 
     Mature polypeptide: The term “mature polypeptide” means a polypeptide in its final form following translation and any post-translational modifications, such as N-terminal processing, C-terminal truncation, glycosylation, phosphorylation, etc. 
     In one aspect, the mature polypeptide is amino acids 1 to 391 of SEQ ID NO: 1. In one aspect, the mature polypeptide is amino acids 1 to 391 of SEQ ID NO: 2. In one aspect, the mature polypeptide is amino acids 1 to 392 of SEQ ID NO: 3. In one aspect, the mature polypeptide is amino acids 1 to 391 of SEQ ID NO: 4. In one aspect, the mature polypeptide is amino acids 1 to 393 of SEQ ID NO: 5. In one aspect, the mature polypeptide is amino acids 1 to 391 of SEQ ID NO: 6. 
     It is known in the art that a host cell may produce a mixture of two of more different mature polypeptides (i.e., with a different C-terminal and/or N-terminal amino acid) expressed by the same polynucleotide. It is also known in the art that different host cells process polypeptides differently, and thus, one host cell expressing a polynucleotide may produce a different mature polypeptide (e.g., having a different C-terminal and/or N-terminal amino acid) as compared to another host cell expressing the same polynucleotide. 
     Mature polypeptide coding sequence: The term “mature polypeptide coding sequence” means a polynucleotide that encodes a mature polypeptide having xylanase activity. 
     Mutant: The term “mutant” means a polynucleotide encoding a variant. 
     Nucleic acid construct: The term “nucleic acid construct” means a nucleic acid molecule, either single- or double-stranded, which is isolated from a naturally occurring gene or is modified to contain segments of nucleic acids in a manner that would not otherwise exist in nature or which is synthetic, which comprises one or more control sequences. 
     Nutrient Digestibility: The term “nutrient digestibility” means the fraction of a nutrient that disappears from the gastro-intestinal tract or a specified segment of the gastro-intestinal tract, e.g., the small intestine. Nutrient digestibility may be measured as the difference between what is administered to the subject and what. comes out in the faeces of the subject, or between what is administered to the subject and what remains in the digesta on a specified segment of the gastro intestinal tract, e.g., the ileum. 
     Nutrient digestibility as used herein may be measured by the difference between the intake of a nutrient and the excreted nutrient by means of the total collection of excreta during a period of time; or with the use of an inert marker that is not absorbed by the animal, and allows the researcher calculating the amount of nutrient that disappeared in the entire gastro-intestinal tract or a segment of the gastro-intestinal tract. Such an inert marker may be titanium dioxide, chromic oxide or acid insoluble ash. Digestibility may be expressed as a percentage of the nutrient in the feed, or as mass units of digestible nutrient per mass units of nutrient in the feed. Nutrient digestibility as used herein encompasses starch digestibility, fat digestibility, protein digestibility, and amino acid digestibility. 
     Energy digestibility as used herein means the gross energy of the feed consumed minus the gross energy of the faeces or the gross energy of the feed consumed minus the gross energy of the remaining digesta on a specified segment of the gastro-intestinal tract of the animal, e.g., the ileum. Metabolizable energy as used herein refers to apparent metabolizable energy and means the gross energy of the feed consumed minus the gross energy contained in the faeces, urine, and gaseous products of digestion. Energy digestibility and metabolizable energy may be measured as the difference between the intake of gross energy and the gross energy excreted in the faeces or the digesta present in specified segment of the gastro-intestinal tract using the same methods to measure the digestibility of nutrients, with appropriate corrections for nitrogen excretion to calculate metabolizable energy of feed. 
     Operably linked: The term “operably linked” means a configuration in which a control sequence is placed at an appropriate position relative to the coding sequence of a polynucleotide such that the control sequence directs expression of the coding sequence. 
     Parent or parent xylanase: The term “parent” or “parent xylanase” means a xylanase to which a substitution is made to produce the xylanase variants of the present invention. The parent may be a naturally occurring (wild-type) polypeptide or a variant or fragment thereof. 
     Percentage solubilized xylan: The term “percentage solubilized xylan” means the amount of xylose measured in the supernatant after incubation with an enzyme compared to the total amount of xylose present in the substrate before the incubation with the enzyme. For the purpose of the present invention, the percentage solubilized xylan may be calculated using defatted destarched maize (DFDSM) as substrate. DFDSM is prepared according to ‘Preparation of Defatted Destarched Maize (DFDSM)’ in the experimental section. 
     The percentage solubilized xylan from defatted destarched maize (DFDSM) may be determined using the reaction conditions 20 μg enzyme/g DFDSM and incubation at 40° C., pH 5 for 2.5 hours as described in the ‘Xylose solubilization assay’ herein. Thus the term ‘is performed under the reaction conditions 20 μg xylanase variant per gram defatted destarched maize (DFDSM) and incubation at 40° C., pH 5 for 2.5 hours’ is to be understood that the percentage solubilised xylan is calculated as described in the ‘Xylose solubilization assay’ herein. 
     In a more detailed embodiment, 2% (w/w) DFDSM suspension was prepared in 100 mM sodium acetate, 5 mM CaCl 2 , pH 5 and allowed to hydrate for 30 min at room temperature under gently stirring. After hydration, 200 μl substrate suspension was pipetted into a 96 well plate and mixed with 20 μl enzyme solution to obtain a final enzyme concentration of 20 PPM relative to substrate (20 μg enzyme/g substrate). The enzyme/substrate mixtures were left for hydrolysis in 2.5 h at 40° C. under gently agitation (500 RPM) in a plate incubator. After enzymatic hydrolysis, the enzyme/substrate plates were centrifuged for 10 min at 3000 RPM and 50 μl supernatant was mixed with 100 μl 1.6 M HCl and transferred to 300 μl PCR tubes and left for acid hydrolysis for 40 min at 90° C. in a PCR machine. Samples were neutralized with 125 μl 1.4 M NaOH after acid hydrolysis and loaded on the HPAE-PAD for mono-saccharide analysis. 
     Sequence identity: The relatedness between two amino acid sequences or between two nucleotide sequences is described by the parameter “sequence identity”. 
     For purposes of the present invention, the sequence identity between two amino acid sequences is determined using the Needleman-Wunsch algorithm (Needleman and Wunsch, 1970 , J. Mol. Biol.  48: 443-453) as implemented in the Needle program of the EMBOSS package (EMBOSS: The European Molecular Biology Open Software Suite, Rice et al., 2000 , Trends Genet.  16: 276-277), e.g., version 5.0.0 or later. The parameters used are gap open penalty of 10, gap extension penalty of 0.5, and the EBLOSUM62 (EMBOSS version of BLOSUM62) substitution matrix. The output of Needle labeled “longest identity” (obtained using the -nobrief option) is used as the percent identity and is calculated as follows: 
       (Identical Residues×100)/(Length of Alignment−Total Number of Gaps in Alignment)
 
     For purposes of the present invention, the sequence identity between two deoxyribonucleotide sequences is determined using the Needleman-Wunsch algorithm (Needleman and Wunsch, 1970, supra) as implemented in the Needle program of the EMBOSS package (EMBOSS: The European Molecular Biology Open Software Suite, Rice et al., 2000, supra), e.g., version 5.0.0 or later. The parameters used are gap open penalty of 10, gap extension penalty of 0.5, and the EDNAFULL (EMBOSS version of NCBI NUC4.4) substitution matrix. The output of Needle labeled “longest identity” (obtained using the -nobrief option) is used as the percent identity and is calculated as follows: 
       (Identical Deoxyribonucleotides×100)/(Length of Alignment−Total Number of Gaps in Alignment)
 
     Variant: The term “variant” means a polypeptide having xylanase activity comprising an alteration, i.e., a substitution, insertion, and/or deletion, at one or more (e.g., several) positions. A substitution means replacement of the amino acid occupying a position with a different amino acid; a deletion means removal of the amino acid occupying a position; and an insertion means adding an amino acid adjacent to and immediately following the amino acid occupying a position. The variants of the present invention have at least 20%, e.g., at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 100% of the xylanase activity of the polypeptide of SEQ ID NO: 1. 
     Wild-type xylanase: The term “wild-type” xylanase means a xylanase expressed by a naturally occurring microorganism, such as a bacterium, yeast, or filamentous fungus found in nature. 
     Conventions for Designation of Variants 
     For purposes of the present invention, SEQ ID NO: 1 is used to determine the corresponding amino acid residue in another xylanase. The amino acid sequence of another xylanase is aligned with SEQ ID NO: 1, and based on the alignment, the amino acid position number corresponding to any amino acid residue in SEQ ID NO: 1 is determined using the Needleman-Wunsch algorithm (Needleman and Wunsch, 1970 , J. Mol. Biol.  48: 443-453) as implemented in the Needle program of the EMBOSS package (EMBOSS: The European Molecular Biology Open Software Suite, Rice et al., 2000 , Trends Genet.  16: 276-277), e.g., version 5.0.0 or later. The parameters used are gap open penalty of 10, gap extension penalty of 0.5, and the EBLOSUM62 (EMBOSS version of BLOSUM62) substitution matrix. 
     Identification of the corresponding amino acid residue in another xylanase can be determined by an alignment of multiple polypeptide sequences using several computer programs including, but not limited to, MUSCLE (multiple sequence comparison by log-expectation; version 3.5 or later; Edgar, 2004 , Nucleic Acids Research  32: 1792-1794), MAFFT (version 6.857 or later; Katoh and Kuma, 2002 , Nucleic Acids Research  30: 3059-3066; Katoh et al., 2005 , Nucleic Acids Research  33: 511-518; Katoh and Toh, 2007 , Bioinformatics  23: 372-374; Katoh et al., 2009 , Methods in Molecular Biology  537: 39-64; Katoh and Toh, 2010 , Bioinformatics  26: 1899-1900), and EMBOSS EMMA employing ClustalW (1.83 or later; Thompson et al., 1994 , Nucleic Acids Research  22: 4673-4680), using their respective default parameters. 
     When the other enzyme has diverged from the polypeptide of SEQ ID NO: 1 such that traditional sequence-based comparison fails to detect their relationship (Lindahl and Elofsson, 2000 , J. Mol. Biol.  295: 613-615), other pairwise sequence comparison algorithms can be used. Greater sensitivity in sequence-based searching can be attained using search programs that utilize probabilistic representations of polypeptide families (profiles) to search databases. For example, the PSI-BLAST program generates profiles through an iterative database search process and is capable of detecting remote homologs (Atschul et al., 1997 , Nucleic Acids Res.  25: 3389-3402). Even greater sensitivity can be achieved if the family or superfamily for the polypeptide has one or more representatives in the protein structure databases. Programs such as GenTHREADER (Jones, 1999 , J. Mol. Biol.  287: 797-815; McGuffin and Jones, 2003 , Bioinformatics  19: 874-881) utilize information from a variety of sources (PSI-BLAST, secondary structure prediction, structural alignment profiles, and solvation potentials) as input to a neural network that predicts the structural fold for a query sequence. Similarly, the method of Gough et al., 2000 , J. Mol. Biol.  313: 903-919, can be used to align a sequence of unknown structure with the superfamily models present in the SCOP database. These alignments can in turn be used to generate homology models for the polypeptide, and such models can be assessed for accuracy using a variety of tools developed for that purpose. 
     For proteins of known structure, several tools and resources are available for retrieving and generating structural alignments. For example the SCOP superfamilies of proteins have been structurally aligned, and those alignments are accessible and downloadable. Two or more protein structures can be aligned using a variety of algorithms such as the distance alignment matrix (Holm and Sander, 1998 , Proteins  33: 88-96) or combinatorial extension (Shindyalov and Bourne, 1998 , Protein Engineering  11: 739-747), and implementation of these algorithms can additionally be utilized to query structure databases with a structure of interest in order to discover possible structural homologs (e.g., Holm and Park, 2000 , Bioinformatics  16: 566-567). 
     In describing the variants of the present invention, the nomenclature described below is adapted for ease of reference. The accepted IUPAC single letter or three letter amino acid abbreviation is employed. 
     Substitutions. For an amino acid substitution, the following nomenclature is used: Original amino acid, position, substituted amino acid. Accordingly, the substitution of threonine at position 226 with alanine is designated as “Thr226Ala” or “T226A”. Multiple mutations are separated by addition marks (“+”), e.g., “Gly205Arg+Ser411Phe” or “G205R+S411F”, representing substitutions at positions 205 and 411 of glycine (G) with arginine (R) and serine (S) with phenylalanine (F), respectively. 
     Deletions. For an amino acid deletion, the following nomenclature is used: Original amino acid, position, *. Accordingly, the deletion of glycine at position 195 is designated as “Gly195*” or “G195*”. Multiple deletions are separated by addition marks (“+”), e.g., “Gly195*+Ser411*” or “G195*+S411*”. 
     Insertions. For an amino acid insertion, the following nomenclature is used: Original amino acid, position, original amino acid, inserted amino acid. Accordingly the insertion of lysine after glycine at position 195 is designated “Gly195GlyLys” or “G195GK”. An insertion of multiple amino acids is designated [Original amino acid, position, original amino acid, inserted amino acid #1, inserted amino acid #2; etc.]. For example, the insertion of lysine and alanine after glycine at position 195 is indicated as “Gly195GlyLysAla” or “G195GKA”. 
     In such cases the inserted amino acid residue(s) are numbered by the addition of lower case letters to the position number of the amino acid residue preceding the inserted amino acid residue(s). In the above example, the sequence would thus be: 
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 Parent: 
                 Variant: 
               
               
                   
                   
               
             
            
               
                   
                 195 
                 195 195a 195b 
               
               
                   
                 G 
                 G - K - A 
               
               
                   
                   
               
            
           
         
       
     
     Multiple alterations. Variants comprising multiple alterations are separated by a plus sign (“+”), e.g., “Arg170Tyr+Gly195Glu” or “R170Y+G195E” representing a substitution of arginine and glycine at positions 170 and 195 with tyrosine and glutamic acid, respectively. 
     Different alterations. Where different alterations can be introduced at a position, the different alterations are separated by a comma, e.g., “Arg170Tyr,Glu” represents a substitution of arginine at position 170 with tyrosine or glutamic acid. Thus, “Tyr167Gly,Ala+Arg170Gly,Ala” designates the following variants: 
     “Tyr167Gly+Arg170Gly”, “Tyr167Gly+Arg170Ala”, “Tyr167Ala+Arg170Gly”, and “Tyr167Ala+Arg170Ala”. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention relates to xylanase variants having one or more substitutions having an improved property, such as improved thermostability. 
     Preparation of Variants 
     In a first aspect, the invention relates to methods for obtaining a variant having xylanase activity. Thus, the invention relates to a method for obtaining a xylanase variant, comprising 
     (a) introducing into a parent xylanase a substitution at one or more positions corresponding to positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 31, 32, 33, 34, 39, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 64, 65, 67, 68, 79, 82, 88, 90, 94, 101, 102, 104, 110, 112, 113, 116, 119,120, 123, 126, 127, 128, 129, 131, 135,143, 145, 146, 159, 160, 165, 168,176, 179, 181, 188, 191,194, 195, 196, 197, 205, 209, 212, 217, 218, 221, 224, 231, 235, 237, 238, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 338, 339, 340, 342, 343, 344, 345, 346, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1, wherein the xylanase variant has xylanase activity and has at least 70% sequence identity to SEQ ID NO: 1; and 
     (b) recovering the xylanase variant. 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the xylanase variant has at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NO: 1. 
     In one embodiment, the parent xylanase has at least 70%, e.g., at at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 1. In one embodiment, the parent xylanase is obtained or obtainable from the taxonomic order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus  Bacillus  or  Paenibacillus , or even more preferably from the taxonomic species  Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis  or  Paenibacillus pabuli . In one embodiment, the parent xylanase has at least 70%, e.g., at at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 1 and is obtained or obtainable from the taxonomic order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus  Bacillus  or  Paenibacillus , or even more preferably from the taxonomic species  Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis  or  Paenibacillus pabuli . In one embodiment, the xylanase is a GH30 subfamily 8 xylanase (herein referred to as GH30_8 xylanases). 
     In one embodiment, the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 1, is a fragment of SEQ ID NO: 1 wherein the fragment has xylanase activity or comprises the amino acid sequence of SEQ ID NO: 1 and an N- and/or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the substitution is selected from the group consisting of A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W and Y, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. 
     In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In one embodiment of the first aspect, the invention relates to a method for obtaining a xylanase variant, comprising: 
     (a) introducing into a parent xylanase having at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or 100%) sequence identity to SEQ ID NO: 1 a substitution at one or more positions corresponding to positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 31, 32, 33, 34, 39, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 64, 65, 67, 68, 79, 82, 88, 90, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 127, 128, 129, 131, 135, 143, 145, 146, 159,160, 165, 168, 176, 179, 181, 188, 191, 194, 195, 196, 197, 205, 209, 212, 217, 218, 221, 224, 231, 235, 237, 238, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 338, 339, 340, 342, 343, 344, 345, 346, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1, wherein the xylanase variant has xylanase activity, has improved thermostability relative to the parent xylanase and has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 95%) sequence identity to SEQ ID NO: 1; and 
     (b) recovering the xylanase variant. 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the parent xylanase is obtained or obtainable from the taxonomic order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus  Bacillus  or  Paenibacillus , or even more preferably from the taxonomic species  Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis  or  Paenibacillus pabuli . In one embodiment, the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 1, is a fragment of SEQ ID NO: 1 wherein the fragment has xylanase activity or comprises the amino acid sequence of SEQ ID NO: 1 and an N- and/or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the substitution is selected from the group consisting of A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W and Y, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. 
     In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In one embodiment of the first aspect, the invention relates to a method for obtaining a xylanase variant, comprising: 
     (a) introducing into a parent xylanase having at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or 100%) sequence identity to SEQ ID NO: 1 a substitution at one or more positions corresponding to positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 31, 32, 33, 34, 39, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 64, 65, 67, 68, 79, 82, 88, 90, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 127, 128, 129, 131, 135, 143, 145, 146, 159, 160, 165, 168,176, 179, 181, 188, 191, 194, 195, 196, 197, 205, 209, 212, 217, 218, 221, 224, 231, 235, 237, 238, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 338, 339, 340, 342, 343, 344, 345, 346, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1, wherein the xylanase variant has xylanase activity, has improved thermostability relative to SEQ ID NO: 1 of at least 0.1° C. (such as at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C.) and has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 95%) sequence identity to SEQ ID NO: 1; and 
     (b) recovering the xylanase variant. 
     In one embodiment, the parent xylanase is obtained or obtainable from the taxonomic order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus  Bacillus  or  Paenibacillus , or even more preferably from the taxonomic species  Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis  or  Paenibacillus pabuli . In one embodiment, the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 1, is a fragment of SEQ ID NO: 1 wherein the fragment has xylanase activity or comprises the amino acid sequence of SEQ ID NO: 1 and an N- and/or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the substitution is selected from the group consisting of A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W and Y, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. 
     In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In one embodiment of the first aspect, the invention relates to a method for obtaining a xylanase variant, comprising 
     (a) introducing into a parent xylanase one or more substitutions selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, A2L, A2Y, S3W, S3F, S3H, S3L, S3G, S3M, S3T, S3P, D4L, D4C, D4Y, D4Q, D4A, D4K, D4P, V5H, V5G, V5P, T6K, T6Q, T6L, T6N, T6R, T6D, T6F, T6H, V7F, V7S, V7C, V7A, V7W, N8Q, N8R, N8D, N8F, N8W, N8Y, N8S, N8M, N8L, N8V, N8T, N8I, N8A, V9H, V9R, V9M, S10A, S10H, S10L, S10I, S10D, S10K, S10V, A11P, A11I, A11N, A11G, A11Y, A11C, A11S, A11F, A11M, A11D, A11L, A11H, A11W, A11E, A11V, A11R, A11Q, E12G, E12R, E12K, E12T, E12V, E12W, E12C, K13Q, K13H, K13N, K13L, K13S, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, Q14D, V15F, V15L, V15N, V15K, V15H, G18H, G18Y, G18W, G18F, G18C, G18S, G18A, F19H, F19Y, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, L31V, T32N, T32D, A33Q, A33H, A33M, A33Y, A33K, A33E, A33R, A33C, A33N, A34F, A34N, A34C, A34L, A34P, A34S, A34Q, A39S, G43W, G43A, G43N, Q44D, Q44N, Q44R, Q44Y, Q44K, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, N45G, N45P, N45T, N45Y, Q46D, Q46H, Q46C, Q46S, Q46T, Q46N, Q46K, G48L, G48V, G48I, G48Q, G48C, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, S50T, E58P, E58K, E58R, N59C, N59V, N59D, N59K, N59L, N59S, N61W, N61L, N61D, N61E, N61H, N61M, N61Y, N61I, N61T, N61F, N61Q, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, N62Q, Y64F, Y64N, K65I, K65L, V67A, V67S, V67F, V67G, V67K, E68W, E68V, E68I, E68A, E68H, E68N, I79K, I79R, I79V, I79A, A82G, P88M, P88F, P88T, P88W, P88Q, D90R, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A112G, A112T, A112V, A113E, A113Q, A113L, A113D, A113S, Q116E, Q116A, Q116G, N119G, N119S, N119V, N119L, N119C, N119R, D120R, D120A, D120S, D120Y, D120L, D120W, D120T, D120G, T123E, T123Y, T123C, T123H, T123Q, T123K, T123V, T123G, T123R, T123I, K126R, K126A, K126Y, K126L, K126F, K126W, K126E, K126H, K126Q, N127P, N127W, N128H, N128K, G129M, G129Q, G129A, G129F, G129W, N131K, N131R, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, H145W, E146R, E146H, E146Y, E146F, E146W, E146A, E146K, E146G, E146S, M159C, R160I, S165Y, S165M, S165I, A168I, A168R, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N181A, N181T, N188M, N188E, N188L, Q191I, Q191K, Q191V, Q191R, Q191L, Q191M, A194H, A194R, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, G205C, G205Q, S209N, S209C, S209W, P212A, P212K, P212Q, P212R, P212E, P212S, P212N, K217Q, K217M, Q218H, Q218I, A221R, A221K, A221H, A221Q, A221C, A221N, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, N238G, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, D280N, D280R, T282M, T282H, T282R, T282C, T282V, T282L, T282E, T282F, K295W, K295T, K295I, K295V, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, R298P, R298Y, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, P299G, P299S, G300A, G300R, V302I, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, V302F, D305W, D305F, D305I, D305M, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307S, T307H, T307E, T307Y, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, N313L, N313C, N313G, N313F, D322F, D322G, D322L, N323A, N323C, N323Q, N323L, N323G, N323R, N323E, N323S, N323Y, N323P, K324S, K324P, S333I, S333R, S333T, N334I, N334A, N334L, T335I, T335A, G336C, G336A, G336E, V337A, V337Q, V337D, V337M, V337E, V337G, N338H, Q339I, Q339T, Q339A, N340S, N340A, N340C, V342A, V342L, V342I, V342R, V342D, L343C, L343Q, L343I, L343A, L343P, L343S, L343D, L343Y, L343F, L343K, L343H, L343E, L343N, Q344I, Q344R, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, N345I, N345V, N345P, G346H, S347R, S347H, S347I, S347A, S347G, S347K, S347Y, S347W, S347T, S347L, S347F, S349R, S349C, S349A, S349V, S349I, S349F, S349Y, S349T, S349M, S349D, N350K, N350A, W354L, S357V, S357Q, S359H, S359Q, S359F, S359R, S359I, S359G, S359Y, S359A, S359P, S359N, S359W, S359E, S360R, S360G, Q363V, Q363R, Q363A, Q363G, Q363H, Q363L, Q363N, Q363F, P364Q, P364H, P364W, P364I, P364L, T366S, T366N, T366W, T366Q, T366C, T366V, T366A, T366S, T366L, T366K, T366R, T366G, T366I, T366Q, N367Y, N367P, N367L, N367A, N367F, N367Q, N367W, N367D, N367E, L368D, L368H, S371F, S371W, S371V, S371E, S371R, S371H, S371Q, S371D, S371I, N373D, N373I, N373E, N373W, N373Y, N373A, N373H, N373Q, H374E, H374F, H374D, H374T, H374S, H374I, H374L, H374W, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, W376Y, W376L, W376E, W376G, W376F, W376R, A377I, A377V, A377M, H378A, H378T, H378I, H378R, H378C, H378M, H378Q, H378N, H378G, H378L, H378V, H378S, H378Y, H378K, H378D, H378P, H378E, H378F, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, P380K, P380H, T385F, T385M, T385R, V388E, V388D, V388Y, V388K, V388H, V388L, V388Q, N390R, N390M, N390P, R391C, R391M, R391G, R391P, R391H and R391V, wherein the position corresponds to the position of SEQ ID NO: 1 and wherein the xylanase variant has xylanase activity and has at least 70% sequence identity to SEQ ID NO: 1; and 
     (b) recovering the xylanase variant. 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the xylanase variant has at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NO: 1. 
     In one embodiment, the parent xylanase has at least 70%, e.g., at at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 1. In one embodiment, the parent xylanase is obtained or obtainable from the taxonomic order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus  Bacillus  or  Paenibacillus , or even more preferably from the taxonomic species  Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis  or  Paenibacillus pabuli . In one embodiment, the parent xylanase has at least 70%, e.g., at at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 1 and is obtained or obtainable from the taxonomic order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus  Bacillus  or  Paenibacillus , or even more preferably from the taxonomic species  Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis  or  Paenibacillus pabuli.    
     In one embodiment, the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 1, is a fragment of SEQ ID NO: 1 wherein the fragment has xylanase activity or comprises the amino acid sequence of SEQ ID NO: 1 and an N- and/or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In one embodiment of the first aspect, the invention relates to a method for obtaining a xylanase variant, comprising 
     (a) introducing into a parent xylanase having at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or 100%) sequence identity to SEQ ID NO: 1 one or more substitutions selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, A2L, A2Y, S3W, S3F, S3H, S3L, S3G, S3M, S3T, S3P, D4L, D4C, D4Y, D4Q, D4A, D4K, D4P, V5H, V5G, V5P, T6K, T6Q, T6L, T6N, T6R, T6D, T6F, T6H, V7F, V7S, V7C, V7A, V7W, N8Q, N8R, N8D, N8F, N8W, N8Y, N8S, N8M, N8L, N8V, N8T, N8I, N8A, V9H, V9R, V9M, S10A, S10H, S10L, S10I, S10D, S10K, S10V, A11P, A11I, A11N, A11G, A11Y, A11C, A11S, A11F, A11M, A11D, A11L, A11H, A11W, A11E, A11V, A11R, A11Q, E12G, E12R, E12K, E12T, E12V, E12W, E12C, K13Q, K13H, K13N, K13L, K13S, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, Q14D, V15F, V15L, V15N, V15K, V15H, G18H, G18Y, G18W, G18F, G18C, G18S, G18A, F19H, F19Y, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, L31V, T32N, T32D, A33Q, A33H, A33M, A33Y, A33K, A33E, A33R, A33C, A33N, A34F, A34N, A34C, A34L, A34P, A34S, A34Q, A39S, G43W, G43A, G43N, Q44D, Q44N, Q44R, Q44Y, Q44K, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, N45G, N45P, N45T, N45Y, Q46D, Q46H, Q46C, Q46S, Q46T, Q46N, Q46K, G48L, G48V, G48I, G48Q, G48C, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, S50T, E58P, E58K, E58R, N59C, N59V, N59D, N59K, N59L, N59S, N61W, N61L, N61D, N61E, N61H, N61M, N61Y, N61I, N61T, N61F, N61Q, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, N62Q, Y64F, Y64N, K65I, K65L, V67A, V67S, V67F, V67G, V67K, E68W, E68V, E68I, E68A, E68H, E68N, I79K, I79R, I79V, I79A, A82G, P88M, P88F, P88T, P88W, P88Q, D90R, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A112G, A112T, A112V, A113E, A113Q, A113L, A113D, A113S, Q116E, Q116A, Q116G, N119G, N119S, N119V, N119L, N119C, N119R, D120R, D120A, D120S, D120Y, D120L, D120W, D120T, D120G, T123E, T123Y, T123C, T123H, T123Q, T123K, T123V, T123G, T123R, T123I, K126R, K126A, K126Y, K126L, K126F, K126W, K126E, K126H, K126Q, N127P, N127W, N128H, N128K, G129M, G129Q, G129A, G129F, G129W, N131K, N131R, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, H145W, E146R, E146H, E146Y, E146F, E146W, E146A, E146K, E146G, E146S, M159C, R160I, S165Y, S165M, S165I, A168I, A168R, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N181A, N181T, N188M, N188E, N188L, Q191I, Q191K, Q191V, Q191R, Q191L, Q191M, A194H, A194R, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, G205C, G205Q, S209N, S209C, S209W, P212A, P212K, P212Q, P212R, P212E, P212S, P212N, K217Q, K217M, Q218H, Q218I, A221R, A221K, A221H, A221Q, A221C, A221N, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, N238G, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, D280N, D280R, T282M, T282H, T282R, T282C, T282V, T282L, T282E, T282F, K295W, K295T, K295I, K295V, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, R298P, R298Y, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, P299G, P299S, G300A, G300R, V302I, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, V302F, D305W, D305F, D305I, D305M, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307S, T307H, T307E, T307Y, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, N313L, N313C, N313G, N313F, D322F, D322G, D322L, N323A, N323C, N323Q, N323L, N323G, N323R, N323E, N323S, N323Y, N323P, K324S, K324P, S333I, S333R, S333T, N334I, N334A, N334L, T335I, T335A, G336C, G336A, G336E, V337A, V337Q, V337D, V337M, V337E, V337G, N338H, Q339I, Q339T, Q339A, N340S, N340A, N340C, V342A, V342L, V342I, V342R, V342D, L343C, L343Q, L343I, L343A, L343P, L343S, L343D, L343Y, L343F, L343K, L343H, L343E, L343N, Q344I, Q344R, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, N345I, N345V, N345P, G346H, S347R, S347H, S347I, S347A, S347G, S347K, S347Y, S347W, S347T, S347L, S347F, S349R, S349C, S349A, S349V, S349I, S349F, S349Y, S349T, S349M, S349D, N350K, N350A, W354L, S357V, S357Q, S359H, S359Q, S359F, S359R, S359I, S359G, S359Y, S359A, S359P, S359N, S359W, S359E, S360R, S360G, Q363V, Q363R, Q363A, Q363G, Q363H, Q363L, Q363N, Q363F, P364Q, P364H, P364W, P364I, P364L, T366S, T366N, T366W, T366Q, T366C, T366V, T366A, T366S, T366L, T366K, T366R, T366G, T366I, T366Q, N367Y, N367P, N367L, N367A, N367F, N367Q, N367W, N367D, N367E, L368D, L368H, S371F, S371W, S371V, S371E, S371R, S371H, S371Q, S371D, S371I, N373D, N373I, N373E, N373W, N373Y, N373A, N373H, N373Q, H374E, H374F, H374D, H374T, H374S, H374I, H374L, H374W, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, W376Y, W376L, W376E, W376G, W376F, W376R, A377I, A377V, A377M, H378A, H378T, H378I, H378R, H378C, H378M, H378Q, H378N, H378G, H378L, H378V, H378S, H378Y, H378K, H378D, H378P, H378E, H378F, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, P380K, P380H, T385F, T385M, T385R, V388E, V388D, V388Y, V388K, V388H, V388L, V388Q, N390R, N390M, N390P, R391C, R391M, R391G, R391P, R391H and R391V, wherein the position corresponds to the position of SEQ ID NO: 1 and wherein the xylanase variant has xylanase activity, has improved thermostability relative to the parent xylanase and has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 95%) sequence identity to SEQ ID NO: 1; and 
     (b) recovering the xylanase variant. 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the parent xylanase is obtained or obtainable from the taxonomic order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus  Bacillus  or  Paenibacillus , or even more preferably from the taxonomic species  Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis  or  Paenibacillus pabuli . In one embodiment, the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 1, is a fragment of SEQ ID NO: 1 wherein the fragment has xylanase activity or comprises the amino acid sequence of SEQ ID NO: 1 and an N- and/or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In one embodiment of the first aspect, the invention relates to a method for obtaining a xylanase variant, comprising 
     (a) introducing into a parent xylanase having at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or 100%) sequence identity to SEQ ID NO: 1 one or more substitutions selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, A2L, A2Y, S3W, S3F, S3H, S3L, S3G, S3M, S3T, S3P, D4L, D4C, D4Y, D4Q, D4A, D4K, D4P, V5H, V5G, V5P, T6K, T6Q, T6L, T6N, T6R, T6D, T6F, T6H, V7F, V7S, V7C, V7A, V7W, N8Q, N8R, N8D, N8F, N8W, N8Y, N8S, N8M, N8L, N8V, N8T, N8I, N8A, V9H, V9R, V9M, S10A, S10H, S10L, S10I, S10D, S10K, S10V, A11P, A11I, A11N, A11G, A11Y, A11C, A11S, A11F, A11M, A11D, A11L, A11H, A11W, A11E, A11V, A11R, A11Q, E12G, E12R, E12K, E12T, E12V, E12W, E12C, K13Q, K13H, K13N, K13L, K13S, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, Q14D, V15F, V15L, V15N, V15K, V15H, G18H, G18Y, G18W, G18F, G18C, G18S, G18A, F19H, F19Y, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, L31V, T32N, T32D, A33Q, A33H, A33M, A33Y, A33K, A33E, A33R, A33C, A33N, A34F, A34N, A34C, A34L, A34P, A34S, A34Q, A39S, G43W, G43A, G43N, Q44D, Q44N, Q44R, Q44Y, Q44K, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, N45G, N45P, N45T, N45Y, Q46D, Q46H, Q46C, Q46S, Q46T, Q46N, Q46K, G48L, G48V, G48I, G48Q, G48C, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, S50T, E58P, E58K, E58R, N59C, N59V, N59D, N59K, N59L, N59S, N61W, N61L, N61D, N61E, N61H, N61M, N61Y, N61I, N61T, N61F, N61Q, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, N62Q, Y64F, Y64N, K65I, K65L, V67A, V67S, V67F, V67G, V67K, E68W, E68V, E68I, E68A, E68H, E68N, I79K, I79R, I79V, I79A, A82G, P88M, P88F, P88T, P88W, P88Q, D90R, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A112G, A112T, A112V, A113E, A113Q, A113L, A113D, A113S, Q116E, Q116A, Q116G, N119G, N119S, N119V, N119L, N119C, N119R, D120R, D120A, D120S, D120Y, D120L, D120W, D120T, D120G, T123E, T123Y, T123C, T123H, T123Q, T123K, T123V, T123G, T123R, T123I, K126R, K126A, K126Y, K126L, K126F, K126W, K126E, K126H, K126Q, N127P, N127W, N128H, N128K, G129M, G129Q, G129A, G129F, G129W, N131K, N131R, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, H145W, E146R, E146H, E146Y, E146F, E146W, E146A, E146K, E146G, E146S, M159C, R160I, S165Y, S165M, S165I, A168I, A168R, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N181A, N181T, N188M, N188E, N188L, Q191I, Q191K, Q191V, Q191R, Q191L, Q191M, A194H, A194R, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, G205C, G205Q, S209N, S209C, S209W, P212A, P212K, P212Q, P212R, P212E, P212S, P212N, K217Q, K217M, Q218H, Q218I, A221R, A221K, A221H, A221Q, A221C, A221N, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, N238G, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, D280N, D280R, T282M, T282H, T282R, T282C, T282V, T282L, T282E, T282F, K295W, K295T, K295I, K295V, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, R298P, R298Y, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, P299G, P299S, G300A, G300R, V302I, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, V302F, D305W, D305F, D305I, D305M, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307S, T307H, T307E, T307Y, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, N313L, N313C, N313G, N313F, D322F, D322G, D322L, N323A, N323C, N323Q, N323L, N323G, N323R, N323E, N323S, N323Y, N323P, K324S, K324P, S333I, S333R, S333T, N334I, N334A, N334L, T335I, T335A, G336C, G336A, G336E, V337A, V337Q, V337D, V337M, V337E, V337G, N338H, Q339I, Q339T, Q339A, N340S, N340A, N340C, V342A, V342L, V342I, V342R, V342D, L343C, L343Q, L343I, L343A, L343P, L343S, L343D, L343Y, L343F, L343K, L343H, L343E, L343N, Q344I, Q344R, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, N345I, N345V, N345P, G346H, S347R, S347H, S347I, S347A, S347G, S347K, S347Y, S347W, S347T, S347L, S347F, S349R, S349C, S349A, S349V, S349I, S349F, S349Y, S349T, S349M, S349D, N350K, N350A, W354L, S357V, S357Q, S359H, S359Q, S359F, S359R, S359I, S359G, S359Y, S359A, S359P, S359N, S359W, S359E, S360R, S360G, Q363V, Q363R, Q363A, Q363G, Q363H, Q363L, Q363N, Q363F, P364Q, P364H, P364W, P364I, P364L, T366S, T366N, T366W, T366Q, T366C, T366V, T366A, T366S, T366L, T366K, T366R, T366G, T366I, T366Q, N367Y, N367P, N367L, N367A, N367F, N367Q, N367W, N367D, N367E, L368D, L368H, S371F, S371W, S371V, S371E, S371R, S371H, S371Q, S371D, S371I, N373D, N373I, N373E, N373W, N373Y, N373A, N373H, N373Q, H374E, H374F, H374D, H374T, H374S, H374I, H374L, H374W, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, W376Y, W376L, W376E, W376G, W376F, W376R, A377I, A377V, A377M, H378A, H378T, H378I, H378R, H378C, H378M, H378Q, H378N, H378G, H378L, H378V, H378S, H378Y, H378K, H378D, H378P, H378E, H378F, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, P380K, P380H, T385F, T385M, T385R, V388E, V388D, V388Y, V388K, V388H, V388L, V388Q, N390R, N390M, N390P, R391C, R391M, R391G, R391P, R391H and R391V, wherein the position corresponds to the position of SEQ ID NO: 1 and wherein the xylanase variant has xylanase activity, has improved thermostability relative to SEQ ID NO: 1 of at least 0.1° C. (such as at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C.) and has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 95%) sequence identity to SEQ ID NO: 1; and 
     (b) recovering the xylanase variant. 
     In one embodiment, the parent xylanase is obtained or obtainable from the taxonomic order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus  Bacillus  or  Paenibacillus , or even more preferably from the taxonomic species  Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis  or  Paenibacillus pabuli . In one embodiment, the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 1, is a fragment of SEQ ID NO: 1 wherein the fragment has xylanase activity or comprises the amino acid sequence of SEQ ID NO: 1 and an N- and/or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In a further embodiment, the invention relates to xylanase variants produced by the methods disclosed in the first aspect. 
     The variants can be prepared using any mutagenesis procedure known in the art, such as site-directed mutagenesis, synthetic gene construction, semi-synthetic gene construction, random mutagenesis, shuffling, etc. 
     Site-directed mutagenesis is a technique in which one or more (e.g., several) mutations are introduced at one or more defined sites in a polynucleotide encoding the parent. 
     Site-directed mutagenesis can be accomplished in vitro by PCR involving the use of oligonucleotide primers containing the desired mutation. Site-directed mutagenesis can also be performed in vitro by cassette mutagenesis involving the cleavage by a restriction enzyme at a site in the plasmid comprising a polynucleotide encoding the parent and subsequent ligation of an oligonucleotide containing the mutation in the polynucleotide. Usually the restriction enzyme that digests the plasmid and the oligonucleotide is the same, permitting sticky ends of the plasmid and the insert to ligate to one another. See, e.g., Scherer and Davis, 1979 , Proc. Natl. Acad. Sci. USA  76: 4949-4955; and Barton et al., 1990 , Nucleic Acids Res.  18: 7349-4966. 
     Site-directed mutagenesis can also be accomplished in vivo by methods known in the art. See, e.g., U.S. Patent Application Publication No. 2004/0171154; Storici et al., 2001 , Nature Biotechnol.  19: 773-776; Kren et al., 1998 , Nat. Med.  4: 285-290; and Calissano and Macino, 1996 , Fungal Genet. Newslett.  43: 15-16. 
     Any site-directed mutagenesis procedure can be used in the present invention. There are many commercial kits available that can be used to prepare variants. 
     Synthetic gene construction entails in vitro synthesis of a designed polynucleotide molecule to encode a polypeptide of interest. Gene synthesis can be performed utilizing a number of techniques, such as the multiplex microchip-based technology described by Tian et al. (2004 , Nature  432: 1050-1054) and similar technologies wherein oligonucleotides are synthesized and assembled upon photo-programmable microfluidic chips. 
     Single or multiple amino acid substitutions, deletions, and/or insertions can be made and tested using known methods of mutagenesis, recombination, and/or shuffling, followed by a relevant screening procedure, such as those disclosed by Reidhaar-Olson and Sauer, 1988 , Science  241: 53-57; Bowie and Sauer, 1989 , Proc. Natl. Acad. Sci. USA  86: 2152-2156; WO 95/17413; or WO 95/22625. Other methods that can be used include error-prone PCR, phage display (e.g., Lowman et al., 1991 , Biochemistry  30: 10832-10837; U.S. Pat. No. 5,223,409; WO 92/06204) and region-directed mutagenesis (Derbyshire et al., 1986 , Gene  46: 145; Ner et al., 1988 , DNA  7: 127). 
     Mutagenesis/shuffling methods can be combined with high-throughput, automated screening methods to detect activity of cloned, mutagenized polypeptides expressed by host cells (Ness et al., 1999 , Nature Biotechnology  17: 893-896). Mutagenized DNA molecules that encode active polypeptides can be recovered from the host cells and rapidly sequenced using standard methods in the art. These methods allow the rapid determination of the importance of individual amino acid residues in a polypeptide. 
     Semi-synthetic gene construction is accomplished by combining aspects of synthetic gene construction, and/or site-directed mutagenesis, and/or random mutagenesis, and/or shuffling. Semi-synthetic construction is typified by a process utilizing polynucleotide fragments that are synthesized, in combination with PCR techniques. Defined regions of genes may thus be synthesized de novo, while other regions may be amplified using site-specific mutagenic primers, while yet other regions may be subjected to error-prone PCR or non-error prone PCR amplification. Polynucleotide subsequences may then be shuffled. 
     Xylanase Variants 
     In a second aspect, the present invention relates to xylanase variants having xylanase activity, wherein the variant has at least 70% sequence identity to SEQ ID NO: 1 and comprises an alteration at one or more positions corresponding to positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 31, 32, 33, 34, 39, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 64, 65, 67, 68, 79, 82, 88, 90, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 127, 128, 129, 131, 135, 143, 145, 146, 159, 160, 165, 168, 176, 179, 181, 188, 191, 194, 195, 196, 197, 205, 209, 212, 217, 218, 221, 224, 231, 235, 237, 238, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 338, 339, 340, 342, 343, 344, 345, 346, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1. 
     In an embodiment, the variant has a sequence identity of at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%, but less than 100%, to SEQ ID NO: 1. 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the number of alterations is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In one embodiment of the second aspect, the present invention relates to xylanase variants having xylanase activity, wherein the variant has at least 70% (such as at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%) sequence identity to SEQ ID NO: 1 and comprises an alteration at one or more positions corresponding to positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 31, 32, 33, 34, 39, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 64, 65, 67, 68, 79, 82, 88, 90, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 127, 128, 129, 131, 135, 143, 145, 146, 159, 160, 165, 168, 176, 179, 181, 188, 191,194, 195, 196, 197, 205, 209, 212, 217, 218, 221, 224, 231, 235, 237, 238, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 338, 339, 340, 342, 343, 344, 345, 346, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1, and wherein the variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1). In one embodiment, the thermostability is improved by at least 0.1° C., such as at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the number of alterations in the variants of the present invention is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 alterations. 
     In an embodiment, the one or more positions are selected from the group consisting of positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 31, 32, 33, 34, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 65, 67, 68, 79, 82, 88, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 128, 129, 135, 143, 145, 146, 159, 160, 165, 168, 176, 179, 181, 188, 191, 194, 195, 196, 197, 209, 212, 217, 218, 221, 224, 231, 235, 237, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 339, 340, 342, 343, 344, 345, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1 and the thermostability is improved by at least 0.5° C. 
     In an embodiment, the one or more positions are selected from the group consisting of positions 2, 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 18, 31, 34, 43, 45, 46, 48, 50, 58, 59, 61, 62, 67, 79, 88, 94, 101, 102, 104, 112, 113, 120, 128, 143, 145, 146, 159, 165, 176, 179, 181, 188, 194, 195, 196, 197, 209, 212, 221, 224, 231, 235, 237, 269, 282, 295, 298, 299, 302, 307, 311, 312, 313, 322, 323, 333, 334, 335, 336, 337, 339, 340, 342, 343, 344, 345, 347, 357, 359, 363, 366, 367, 368, 371, 373, 374, 376, 378, 380, 388 and 391 of SEQ ID NO: 1 and the thermostability is improved by at least 1.0° C. 
     In an embodiment, the one or more positions are selected from the group consisting of positions 2, 4, 9, 11, 12, 14, 18, 31, 45, 48, 50, 59, 61, 79, 88, 94, 101, 102, 104, 143, 145, 146, 159, 165, 176, 179, 181, 196, 197, 209, 212, 224, 231, 235, 269, 282, 295, 298, 299, 302, 307, 312, 322, 333, 335, 336, 340, 344, 357, 359, 366, 368, 371, 376, 378 and 380 of SEQ ID NO: 1 and the thermostability is improved by at least 1.5° C. 
     In an embodiment, the one or more positions are selected from the group consisting of positions 2, 4, 14, 18, 50, 61, 79, 94, 102, 143, 145, 146, 165, 176, 179, 196, 197, 224, 231, 269, 298, 299, 302, 307, 333, 340 and 366 of SEQ ID NO: 1 and the thermostability is improved by at least 2.0° C. 
     In an embodiment, the one or more positions are selected from the group consisting of positions 2, 4, 14, 18, 50, 94, 102, 143, 145, 146, 165, 176, 179, 196, 197, 231, 269, 299, 302 and 333 of SEQ ID NO: 1 and the thermostability is improved by at least 2.5° C. 
     The present invention further relates to novel xylanase variants having xylanase activity, wherein the variant has at least 70% sequence identity to SEQ ID NO: 1 and comprises a substitution at one or more positions corresponding to positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 31, 32, 33, 34, 39, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 64, 65, 67, 68, 79, 82, 88, 90, 94, 101, 102, 104,110, 112, 113, 116, 119, 120, 123, 126, 127, 128, 129, 131, 135, 143, 145, 146, 159, 160, 165, 168, 176, 179, 181, 188, 191, 194, 195, 196, 197, 205, 209, 212, 217, 218, 221, 224, 231, 235, 237, 238, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 338, 339, 340, 342, 343, 344, 345, 346, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1. 
     In an embodiment, the variant has a sequence identity of at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%, but less than 100%, to SEQ ID NO: 1. 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the substitution is selected from the group consisting of A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W and Y, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. 
     In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In one embodiment of the second aspect, the present invention relates to xylanase variants having xylanase activity, wherein the variant has at least 70% (such as at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%) sequence identity to SEQ ID NO: 1 and comprises a substitution at one or more positions corresponding to positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 31, 32, 33, 34, 39, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 64, 65, 67, 68, 79, 82, 88, 90, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 127, 128, 129, 131, 135, 143, 145, 146, 159, 160, 165, 168, 176, 179, 181, 188, 191, 194, 195, 196, 197, 205, 209, 212, 217, 218, 221, 224, 231, 235, 237, 238, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 338, 339, 340, 342, 343, 344, 345, 346, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1, and wherein the variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1). In one embodiment, the thermostability is improved by at least 0.1° C., such as at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the substitution is selected from the group consisting of A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W and Y, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. 
     In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In an embodiment, the one or more positions are selected from the group consisting of positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 31, 32, 33, 34, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 65, 67, 68, 79, 82, 88, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 128, 129, 135, 143, 145, 146, 159, 160, 165, 168, 176, 179, 181, 188, 191, 194, 195, 196, 197, 209, 212, 217, 218, 221, 224, 231, 235, 237, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 339, 340, 342, 343, 344, 345, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1 and the thermostability is improved by at least 0.5° C. 
     In an embodiment, the one or more positions are selected from the group consisting of positions 2, 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 18, 31, 34, 43, 45, 46, 48, 50, 58, 59, 61, 62, 67, 79, 88, 94, 101, 102, 104, 112, 113, 120, 128, 143, 145, 146, 159, 165, 176, 179, 181, 188, 194, 195, 196, 197, 209, 212, 221, 224, 231, 235, 237, 269, 282, 295, 298, 299, 302, 307, 311, 312, 313, 322, 323, 333, 334, 335, 336, 337, 339, 340, 342, 343, 344, 345, 347, 357, 359, 363, 366, 367, 368, 371, 373, 374, 376, 378, 380, 388 and 391 of SEQ ID NO: 1 and the thermostability is improved by at least 1.0° C. 
     In an embodiment, the one or more positions are selected from the group consisting of positions 2, 4, 9, 11, 12, 14, 18, 31, 45, 48, 50, 59, 61, 79, 88, 94, 101, 102, 104, 143, 145, 146, 159, 165, 176, 179, 181, 196, 197, 209, 212, 224, 231, 235, 269, 282, 295, 298, 299, 302, 307, 312, 322, 333, 335, 336, 340, 344, 357, 359, 366, 368, 371, 376, 378 and 380 of SEQ ID NO: 1 and the thermostability is improved by at least 1.5° C. 
     In an embodiment, the one or more positions are selected from the group consisting of positions 2, 4, 14, 18, 50, 61, 79, 94, 102, 143, 145, 146, 165, 176, 179, 196, 197, 224, 231, 269, 298, 299, 302, 307, 333, 340 and 366 of SEQ ID NO: 1 and the thermostability is improved by at least 2.0° C. 
     In an embodiment, the one or more positions are selected from the group consisting of positions 2, 4, 14, 18, 50, 94, 102, 143, 145, 146, 165, 176, 179, 196, 197, 231, 269, 299, 302 and 333 of SEQ ID NO: 1 and the thermostability is improved by at least 2.5° C. 
     In one embodiment of the second aspect, the present invention relates to xylanase variants having xylanase activity, wherein the variant has at least 70% sequence identity to SEQ ID NO: 1 and comprises one or more substitutions selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, A2L, A2Y, S3W, S3F, S3H, S3L, S3G, S3M, S3T, S3P, D4L, D4C, D4Y, D4Q, D4A, D4K, D4P, V5H, V5G, V5P, T6K, T6Q, T6L, T6N, T6R, T6D, T6F, T6H, V7F, V7S, V7C, V7A, V7W, N8Q, N8R, N8D, N8F, N8W, N8Y, N8S, N8M, N8L, N8V, N8T, N8I, N8A, V9H, V9R, V9M, S10A, S10H, S10L, S10I, S10D, S10K, S10V, A11P, A11I, A11N, A11G, A11Y, A11C, A11S, A11F, A11M, A11D, A11L, A11H, A11W, A11E, A11V, A11R, A11Q, E12G, E12R, E12K, E12T, E12V, E12W, E12C, K13Q, K13H, K13N, K13L, K13S, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, Q14D, V15F, V15L, V15N, V15K, V15H, G18H, G18Y, G18W, G18F, G18C, G18S, G18A, F19H, F19Y, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, L31V, T32N, T32D, A33Q, A33H, A33M, A33Y, A33K, A33E, A33R, A33C, A33N, A34F, A34N, A34C, A34L, A34P, A34S, A34Q, A39S, G43W, G43A, G43N, Q44D, Q44N, Q44R, Q44Y, Q44K, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, N45G, N45P, N45T, N45Y, Q46D, Q46H, Q46C, Q46S, Q46T, Q46N, Q46K, G48L, G48V, G48I, G48Q, G48C, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, S50T, E58P, E58K, E58R, N59C, N59V, N59D, N59K, N59L, N59S, N61W, N61L, N61D, N61E, N61H, N61M, N61Y, N61I, N61T, N61F, N61Q, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, N62Q, Y64F, Y64N, K65I, K65L, V67A, V67S, V67F, V67G, V67K, E68W, E68V, E68I, E68A, E68H, E68N, I79K, I79R, I79V, I79A, A82G, P88M, P88F, P88T, P88W, P88Q, D90R, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A112G, A112T, A112V, A113E, A113Q, A113L, A113D, A113S, Q116E, Q116A, Q116G, N119G, N119S, N119V, N119L, N119C, N119R, D120R, D120A, D120S, D120Y, D120L, D120W, D120T, D120G, T123E, T123Y, T123C, T123H, T123Q, T123K, T123V, T123G, T123R, T123I, K126R, K126A, K126Y, K126L, K126F, K126W, K126E, K126H, K126Q, N127P, N127W, N128H, N128K, G129M, G129Q, G129A, G129F, G129W, N131K, N131R, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, H145W, E146R, E146H, E146Y, E146F, E146W, E146A, E146K, E146G, E146S, M159C, R160I, S165Y, S165M, S165I, A168I, A168R, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N181A, N181T, N188M, N188E, N188L, Q191I, Q191K, Q191V, Q191R, Q191L, Q191M, A194H, A194R, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, G205C, G205Q, S209N, S209C, S209W, P212A, P212K, P212Q, P212R, P212E, P212S, P212N, K217Q, K217M, Q218H, Q218I, A221R, A221K, A221H, A221Q, A221C, A221N, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, N238G, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, D280N, D280R, T282M, T282H, T282R, T282C, T282V, T282L, T282E, T282F, K295W, K295T, K295I, K295V, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, R298P, R298Y, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, P299G, P299S, G300A, G300R, V302I, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, V302F, D305W, D305F, D305I, D305M, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307S, T307H, T307E, T307Y, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, N313L, N313C, N313G, N313F, D322F, D322G, D322L, N323A, N323C, N323Q, N323L, N323G, N323R, N323E, N323S, N323Y, N323P, K324S, K324P, S333I, S333R, S333T, N334I, N334A, N334L, T335I, T335A, G336C, G336A, G336E, V337A, V337Q, V337D, V337M, V337E, V337G, N338H, Q339I, Q339T, Q339A, N340S, N340A, N340C, V342A, V342L, V342I, V342R, V342D, L343C, L343Q, L343I, L343A, L343P, L343S, L343D, L343Y, L343F, L343K, L343H, L343E, L343N, Q344I, Q344R, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, N345I, N345V, N345P, G346H, S347R, S347H, S347I, S347A, S347G, S347K, S347Y, S347W, S347T, S347L, S347F, S349R, S349C, S349A, S349V, S349I, S349F, S349Y, S349T, S349M, S349D, N350K, N350A, W354L, S357V, S357Q, S359H, S359Q, S359F, S359R, S359I, S359G, S359Y, S359A, S359P, S359N, S359W, S359E, S360R, S360G, Q363V, Q363R, Q363A, Q363G, Q363H, Q363L, Q363N, Q363F, P364Q, P364H, P364W, P364I, P364L, T366S, T366N, T366W, T366Q, T366C, T366V, T366A, T366S, T366L, T366K, T366R, T366G, T366I, T366Q, N367Y, N367P, N367L, N367A, N367F, N367Q, N367W, N367D, N367E, L368D, L368H, S371F, S371W, S371V, S371E, S371R, S371H, S371Q, S371D, S371I, N373D, N373I, N373E, N373W, N373Y, N373A, N373H, N373Q, H374E, H374F, H374D, H374T, H374S, H374I, H374L, H374W, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, W376Y, W376L, W376E, W376G, W376F, W376R, A377I, A377V, A377M, H378A, H378T, H378I, H378R, H378C, H378M, H378Q, H378N, H378G, H378L, H378V, H378S, H378Y, H378K, H378D, H378P, H378E, H378F, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, P380K, P380H, T385F, T385M, T385R, V388E, V388D, V388Y, V388K, V388H, V388L, V388Q, N390R, N390M, N390P, R391C, R391M, R391G, R391P, R391H and R391V (wherein the position corresponds to the position of SEQ ID NO: 1). 
     In an embodiment, the variant has a sequence identity of at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%, but less than 100%, to SEQ ID NO: 1. 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In one embodiment of the second aspect, the present invention relates to xylanase variants having xylanase activity, wherein the variant has at least 70% (such as at least 75%, e.g at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%) sequence identity to SEQ ID NO: 1 and comprises one or more substitutions selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, A2L, A2Y, S3W, S3F, S3H, S3L, S3G, S3M, S3T, S3P, D4L, D4C, D4Y, D4Q, D4A, D4K, D4P, V5H, V5G, V5P, T6K, T6Q, T6L, T6N, T6R, T6D, T6F, T6H, V7F, V7S, V7C, V7A, V7W, N8Q, N8R, N8D, N8F, N8W, N8Y, N8S, N8M, N8L, N8V, N8T, N8I, N8A, V9H, V9R, V9M, S10A, S10H, S10L, S10I, S10D, S10K, S10V, A11P, A11I, A11N, A11G, A11Y, A11C, A11S, A11F, A11M, A11D, A11L, A11H, A11W, A11E, A11V, A11R, A11Q, E12G, E12R, E12K, E12T, E12V, E12W, E12C, K13Q, K13H, K13N, K13L, K13S, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, Q14D, V15F, V15L, V15N, V15K, V15H, G18H, G18Y, G18W, G18F, G18C, G18S, G18A, F19H, F19Y, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, L31V, T32N, T32D, A33Q, A33H, A33M, A33Y, A33K, A33E, A33R, A33C, A33N, A34F, A34N, A34C, A34L, A34P, A34S, A34Q, A39S, G43W, G43A, G43N, Q44D, Q44N, Q44R, Q44Y, Q44K, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, N45G, N45P, N45T, N45Y, Q46D, Q46H, Q46C, Q46S, Q46T, Q46N, Q46K, G48L, G48V, G48I, G48Q, G48C, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, S50T, E58P, E58K, E58R, N59C, N59V, N59D, N59K, N59L, N59S, N61W, N61L, N61D, N61E, N61H, N61M, N61Y, N61I, N61T, N61F, N61Q, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, N62Q, Y64F, Y64N, K65I, K65L, V67A, V67S, V67F, V67G, V67K, E68W, E68V, E68I, E68A, E68H, E68N, I79K, I79R, I79V, I79A, A82G, P88M, P88F, P88T, P88W, P88Q, D90R, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A112G, A112T, A112V, A113E, A113Q, A113L, A113D, A113S, Q116E, Q116A, Q116G, N119G, N119S, N119V, N119L, N119C, N119R, D120R, D120A, D120S, D120Y, D120L, D120W, D120T, D120G, T123E, T123Y, T123C, T123H, T123Q, T123K, T123V, T123G, T123R, T123I, K126R, K126A, K126Y, K126L, K126F, K126W, K126E, K126H, K126Q, N127P, N127W, N128H, N128K, G129M, G129Q, G129A, G129F, G129W, N131K, N131R, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, H145W, E146R, E146H, E146Y, E146F, E146W, E146A, E146K, E146G, E146S, M159C, R160I, S165Y, S165M, S165I, A168I, A168R, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N181A, N181T, N188M, N188E, N188L, Q191I, Q191K, Q191V, Q191R, Q191L, Q191M, A194H, A194R, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, G205C, G205Q, S209N, S209C, S209W, P212A, P212K, P212Q, P212R, P212E, P212S, P212N, K217Q, K217M, Q218H, Q218I, A221R, A221K, A221H, A221Q, A221C, A221N, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, N238G, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, D280N, D280R, T282M, T282H, T282R, T282C, T282V, T282L, T282E, T282F, K295W, K295T, K295I, K295V, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, R298P, R298Y, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, P299G, P299S, G300A, G300R, V302I, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, V302F, D305W, D305F, D305I, D305M, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307S, T307H, T307E, T307Y, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, N313L, N313C, N313G, N313F, D322F, D322G, D322L, N323A, N323C, N323Q, N323L, N323G, N323R, N323E, N323S, N323Y, N323P, K324S, K324P, S333I, S333R, S333T, N334I, N334A, N334L, T335I, T335A, G336C, G336A, G336E, V337A, V337Q, V337D, V337M, V337E, V337G, N338H, Q339I, Q339T, Q339A, N340S, N340A, N340C, V342A, V342L, V342I, V342R, V342D, L343C, L343Q, L343I, L343A, L343P, L343S, L343D, L343Y, L343F, L343K, L343H, L343E, L343N, Q344I, Q344R, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, N345I, N345V, N345P, G346H, S347R, S347H, S347I, S347A, S347G, S347K, S347Y, S347W, S347T, S347L, S347F, S349R, S349C, S349A, S349V, S349I, S349F, S349Y, S349T, S349M, S349D, N350K, N350A, W354L, S357V, S357Q, S359H, S359Q, S359F, S359R, S359I, S359G, S359Y, S359A, S359P, S359N, S359W, S359E, S360R, S360G, Q363V, Q363R, Q363A, Q363G, Q363H, Q363L, Q363N, Q363F, P364Q, P364H, P364W, P364I, P364L, T366S, T366N, T366W, T366Q, T366C, T366V, T366A, T366S, T366L, T366K, T366R, T366G, T366I, T366Q, N367Y, N367P, N367L, N367A, N367F, N367Q, N367W, N367D, N367E, L368D, L368H, S371F, S371W, S371V, S371E, S371R, S371H, S371Q, S371D, S371I, N373D, N373I, N373E, N373W, N373Y, N373A, N373H, N373Q, H374E, H374F, H374D, H374T, H374S, H374I, H374L, H374W, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, W376Y, W376L, W376E, W376G, W376F, W376R, A377I, A377V, A377M, H378A, H378T, H378I, H378R, H378C, H378M, H378Q, H378N, H378G, H378L, H378V, H378S, H378Y, H378K, H378D, H378P, H378E, H378F, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, P380K, P380H, T385F, T385M, T385R, V388E, V388D, V388Y, V388K, V388H, V388L, V388Q, N390R, N390M, N390P, R391C, R391M, R391G, R391P, R391H and R391V, wherein the variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) (wherein the position corresponds to the position of SEQ ID NO: 1). 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, S3W, S3F, S3H, S3L, D4L, D4C, V5H, T6K, T6Q, T6L, T6N, V7F, V7S, V7C, V7A, N8Q, N8R, N8D, N8F, N8W, N8Y, N8S, N8M, N8L, V9H, V9R, V9M, S10A, S10H, S10L, S10I, A11P, A11I, A11N, A11G, A11Y, A11C, A11S, A11F, A11M, A11D, A11L, A11H, A11W, A11E, E12G, E12R, E12K, E12T, E12V, E12W, K13Q, K13H, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, V15F, V15L, V15N, V15K, G18H, G18Y, G18W, G18F, G18C, G18S, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, T32N, T32D, A33Q, A33H, A33M, A33Y, A34F, A34N, G43W, G43A, G43N, Q44D, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, Q46D, Q46H, Q46C, Q46S, Q46T, G48L, G48V, G48I, G48Q, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, S50T, E58P, E58K, N59C, N59V, N59D, N59K, N61W, N61L, N61D, N61E, N61H, N61M, N61Y, N61I, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, K65I, K65L, V67A, V67S, V67F, E68W, E68V, E68I, I79K, I79R, A82G, P88M, P88F, P88T, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A112G, A112T, A113E, A113Q, A113L, Q116E, Q116A, Q116G, N119G, N119S, D120R, D120A, D120S, D120Y, D120L, T123E, T123Y, T123C, T123H, K126R, N128H, G129M, G129Q, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, E146R, E146H, E146Y, E146F, E146W, E146A, M159C, R160I, S165Y, S165M, A168I, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N181A, N188M, Q191I, Q191K, Q191V, A194H, A194R, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, S209N, S209C, P212A, P212K, P212Q, P212R, P212E, P212S, P212N, K217Q, Q218H, A221R, A221K, A221H, A221Q, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, D280N, T282M, T282H, T282R, T282C, T282V, T282L, K295W, K295T, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, G300A, G300R, V302I, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, D305W, D305F, D305I, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307S, T307H, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, D322F, D322G, N323A, N323C, K324S, K324P, S333I, S333R, S333T, N334I, N334A, T335I, T335A, G336C, V337A, V337Q, Q339I, N340S, V342A, V342L, L343C, L343Q, L343I, L343A, L343P, L343S, L343D, L343Y, Q344I, Q344R, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, S347R, S347H, S347I, S347A, S347G, S347K, S349R, S349C, S349A, S349V, N350K, W354L, S357V, S359H, S359Q, S359F, S359R, S359I, S359G, S359Y, S359A, S359P, S360R, Q363V, Q363R, Q363A, Q363G, P364Q, P364H, T366S, T366N, T366W, T366Q, T366C, T366V, T366A, N367Y, N367P, N367L, N367A, N367F, L368D, L368H, S371F, S371W, S371V, S371E, N373D, N373I, N373E, N373W, H374E, H374F, H374D, H374T, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, A377I, H378A, H378T, H378I, H378R, H378C, H378M, H378Q, H378N, H378G, H378L, H378V, H378S, H378Y, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, T385F, T385M, V388E, V388D, V388Y, V388K, N390R, R391C, R391M, R391G and R391 and the thermostability is improved by at least 0.5° C. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, D4L, D4C, V5H, T6K, N8Q, N8R, V9H, S10A, S10H, A11P, A11I, A11N, A11G, A11Y, A11C, A11S, E12G, E12R, E12K, K13Q, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, G18H, G18Y, G18W, G18F, L31Q, L31H, L31P, L31G, L31S, A34F, G43W, N45D, N45W, N45S, N45F, Q46D, Q46H, G48L, G48V, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, S50T, E58P, N59C, N59V, N59D, N61W, N61L, N61D, N61E, N61H, N62A, N62V, N62L, N62C, V67A, V67S, I79K, P88M, P88F, T94H, T101L, T101R, S102R, K104R, A112G, A113E, A113Q, D120R, D120A, D120S, N128H, Y143H, Y143R, H145Y, E146R, E146H, E146Y, E146F, M159C, S165Y, S165M, F176H, F176R, F176Y, F176K, L179D, L179N, L179C, L179A, L179R, L179K, L179S, N181C, N188M, A194H, A194R, N195H, M196L, D197A, D197S, D197Q, D197G, D197P, S209N, S209C, P212A, P212K, P212Q, P212R, P212E, A221R, A221K, D224Q, Y231T, Y231V, Y231S, Y231A, S235A, T237P, Y269Q, Y269M, Y269I, Y269F, Y269L, T282M, T282H, T282R, T282C, T282V, K295W, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, V302I, V302S, V302R, V302T, V302A, V302Q, V302G, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, N311R, N311M, N311I, A312I, A312R, A312M, N313D, D322F, D322G, N323A, S333I, S333R, N334I, N334A, T335I, G336C, V337A, Q339I, N340S, V342A, L343C, L343Q, Q344I, N345C, S347R, S347H, S357V, S359H, S359Q, S359F, Q363V, T366S, T366N, T366W, N367Y, L368D, S371F, S371W, S371V, N373D, N373I, N373E, H374E, H374F, W376A, W376Q, W376D, W376M, H378A, H378T, H378I, H378R, H378C, H378M, P380M, P380D, P380E, P380C, P380V, P380I, P380L, V388E, V388D and R391C and the thermostability is improved by at least 1.0° C. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q, D4L, D4C, V9H, A11P, E12G, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, G18H, G18Y, L31Q, L31H, N45D, G48L, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, S50T, N59C, N61W, N61L, I79K, P88M, P88F, T94H, T101L, T101R, S102R, K104R, Y143H, Y143R, H145Y, E146R, E146H, E146Y, E146F, M159C, S165Y, S165M, F176H, F176R, F176Y, F176K, L179D, L179N, L179C, L179A, L179R, N181C, M196L, D197A, D197S, D197Q, D197G, S209N, S209C, P212A, D224Q, Y231T, Y231V, Y231S, Y231A, S235A, Y269Q, Y269M, T282M, K295W, R298Q, R298A, R298E, R298M, R298T, P299W, P299A, P299K, P299F, P299Y, P299Q, V302I, V302S, V302R, T307I, T307N, T307R, A312I, D322F, S333I, S333R, T335I, G336C, N340S, Q344I, S357V, S359H, T366S, L368D, S371F, W376A, H378A, P380M and P380D and the thermostability is improved by at least 1.5° C. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, D4L, Q14K, Q14Y, Q14A, Q14V, Q14W, G18H, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, N61W, I79K, T94H, S102R, Y143H, Y143R, H145Y, E146R, E146H, S165Y, S165M, F176H, F176R, L179D, L179N, L179C, L179A, M196L, D197A, D197S, D197Q, D197G, D224Q, Y231T, Y231V, Y231S, Y231A, Y269Q, R298Q, P299W, P299A, P299K, P299F, V302I, V302S, T307I, S333I, N340S and T366S and the thermostability is improved by at least 2.0° C. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, D4L, Q14K, Q14Y, G18H, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, T94H, S102R, Y143H, H145Y, E146R, S165Y, F176H, F176R, L179D, L179N, L179C, L179A, M196L, D197A, D197S, D197Q, Y231T, Y231V, Y269Q, P299W, P299A, P299K, V302I and S333I and the thermostability is improved by at least 2.5° C. 
     In one embodiment of the second aspect, the present invention relates to xylanase variants having xylanase activity, wherein the variant has at least 70% (such as at least 75%, e.g at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%) sequence identity to SEQ ID NO: 1 and comprises one or more substitutions selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, A2L, A2Y, S3W, S3F, S3H, S3L, S3G, S3M, S3T, S3P, D4L, D4C, D4Y, D4Q, D4A, D4K, D4P, V5H, V5G, V5P, T6Q, T6L, T6R, T6D, T6F, T6H, V7F, V7S, V7C, V7A, V7W, N8Q, N8F, N8W, N8Y, N8S, N8M, N8L, N8V, N8T, N8I, N8A, V9H, V9R, V9M, S10H, S10L, S10I, S10D, S10K, S10V, A11P, A11I, A11N, A11G, A11Y, A11C, A11F, A11M, A11D, A11L, A11H, A11W, A11E, A11V, A11R, A11Q, E12G, E12R, E12K, E12T, E12V, E12W, E12C, K13Q, K13H, K13N, K13L, K13S, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, Q14D, V15F, V15N, V15K, V15H, G18H, G18Y, G18W, G18F, G18C, G18S, G18A, F19H, F19Y, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, L31V, T32N, T32D, A33Q, A33H, A33M, A33Y, A33K, A33R, A33C, A33N, A34F, A34C, A34L, A34Q, A39S, G43W, G43A, G43N, Q44R, Q44Y, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, N45G, N45P, N45T, N45Y, Q46D, Q46H, Q46C, Q46S, Q46T, Q46N, Q46K, G48L, G48V, G48I, G48Q, G48C, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, E58K, E58R, N59C, N59V, N59K, N59L, N59S, N61W, N61L, N61E, N61H, N61M, N61Y, N61I, N61T, N61F, N61Q, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, Y64F, Y64N, K65I, K65L, V67A, V67S, V67F, V67G, V67K, E68W, E68V, E68I, E68H, E68N, I79K, I79R, I79V, I79A, A82G, P88M, P88F, P88T, P88W, P88Q, D90R, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A112V, A113E, A113Q, A113L, A113S, Q116E, Q116A, Q116G, N119G, N119S, N119V, N119L, N119C, N119R, D120R, D120A, D120S, D120Y, D120L, D120W, D120T, T123E, T123Y, T123C, T123H, T123Q, T123K, T123V, T123G, T123R, T123I, K126A, K126Y, K126L, K126F, K126W, K126E, K126H, K126Q, N127P, N127W, N128H, N128K, G129M, G129Q, G129A, G129F, G129W, N131K, N131R, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, H145W, E146R, E146H, E146Y, E146F, E146W, E146A, E146K, E146G, E146S, M159C, R160I, S165Y, S165M, S165I, A168I, A168R, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N181T, N188M, N188E, N188L, Q191I, Q191V, Q191R, Q191L, Q191M, A194H, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, G205C, G205Q, S209C, S209W, P212K, P212Q, P212R, P212E, P212N, K217Q, K217M, Q218H, Q218I, A221R, A221K, A221H, A221Q, A221C, A221N, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, N238G, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, D280R, T282H, T282R, T282C, T282V, T282E, T282F, K295W, K295T, K295I, K295V, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, R298P, R298Y, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, P299G, P299S, G300A, G300R, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, V302F, D305W, D305F, D305I, D305M, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307H, T307E, T307Y, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, N313L, N313C, N313G, N313F, D322F, D322G, D322L, N323A, N323C, N323Q, N323L, N323G, N323R, N323E, N323S, N323Y, N323P, K324S, K324P, S333I, S333R, N334I, N334L, T335I, G336C, V337Q, V337D, V337M, V337E, V337G, N338H, Q339I, Q339T, Q339A, N340A, N340C, V342L, V342I, V342R, V342D, L343C, L343Q, L343A, L343P, L343S, L343D, L343Y, L343K, L343H, L343E, L343N, Q344I, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, N345I, N345V, N345P, G346H, S347R, S347H, S347I, S347G, S347Y, S347W, S347L, S347F, S349R, S349C, S349V, S349I, S349F, S349Y, S349T, S349M, S349D, N350A, W354L, S357V, S357Q, S359H, S359Q, S359F, S359R, S359I, S359Y, S359A, S359P, S359W, S359E, S360G, Q363V, Q363R, Q363G, Q363H, Q363L, Q363N, Q363F, P364Q, P364H, P364W, P364I, P364L, T366S, T366N, T366W, T366Q, T366C, T366V, T366L, T366K, T366R, T366G, T366I, T366Q, N367Y, N367L, N367F, N367Q, N367W, L368D, L368H, S371F, S371W, S371V, S371E, S371R, S371H, S371Q, S371D, S371I, N373D, N373I, N373W, N373Y, N373A, N373H, N373Q, H374E, H374F, H374D, H374I, H374L, H374W, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, W376Y, W376L, W376E, W376G, W376F, W376R, A377I, A377V, A377M, H378A, H378T, H378I, H378R, H378C, H378M, H378N, H378G, H378L, H378V, H378S, H378Y, H378K, H378D, H378P, H378E, H378F, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, P380K, P380H, T385F, T385M, T385R, V388E, V388D, V388Y, V388K, V388H, V388L, V388Q, N390R, N390M, N390P, R391C, R391M, R391P, R391H and R391V, wherein the variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) (wherein the position corresponds to the position of SEQ ID NO: 1). 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, S3W, S3F, S3H, S3L, D4L, D4C, V5H, T6Q, T6L, V7F, V7S, V7C, V7A, N8Q, N8F, N8W, N8Y, N8S, N8M, N8L, V9H, V9R, V9M, S10H, S10L, S10I, A11P, A11I, A11N, A11G, A11Y, A11C, A11F, A11M, A11D, A11L, A11H, A11W, A11E, E12G, E12R, E12K, E12T, E12V, E12W, K13Q, K13H, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, V15F, V15N, V15K, G18H, G18Y, G18W, G18F, G18C, G18S, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, T32N, T32D, A33Q, A33H, A33M, A33Y, A34F, A34N, G43W, G43A, G43N, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, Q46D, Q46H, Q46C, Q46S, Q46T, G48L, G48V, G48I, G48Q, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, E58K, N59C, N59V, N59K, N61W, N61L, N61E, N61H, N61M, N61Y, N61I, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, K65I, K65L, V67A, V67S, V67F, E68W, E68V, E68I, I79K, I79R, A82G, P88M, P88F, P88T, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A113E, A113Q, A113L, Q116E, Q116A, Q116G, N119G, N119S, D120R, D120A, D120S, D120Y, D120L, T123E, T123Y, T123C, T123H, N128H, G129M, G129Q, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, E146R, E146H, E146Y, E146F, E146W, E146A, M159C, R160I, S165Y, S165M, A168I, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N188M, Q191I, Q191V, A194H, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, S209C, P212K, P212Q, P212R, P212E, P212N, K217Q, Q218H, A221R, A221K, A221H, A221Q, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, T282H, T282R, T282C, T282V, K295W, K295T, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, G300A, G300R, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, D305W, D305F, D305I, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307H, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, D322F, D322G, N323A, N323C, K324S, K324P, S333I, S333R, N334I, T335I, G336C, V337Q, Q339I, V342L, L343C, L343Q, L343A, L343P, L343S, L343D, L343Y, Q344I, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, S347R, S347H, S347I, S347G, S349R, S349C, S349V, W354L, S357V, S359H, S359Q, S359F, S359R, S359I, S359Y, S359A, S359P, Q363V, Q363R, Q363G, P364Q, P364H, T366N, T366W, T366Q, T366C, T366V, N367Y, N367L, N367F, L368D, L368H, S371F, S371W, S371V, S371E, N373D, N373I, N373W, H374E, H374F, H374D, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, A377I, H378A, H378T, H378I, H378R, H378C, H378M, H378N, H378G, H378L, H378V, H378S, H378Y, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, T385F, T385M, V388E, V388D, V388Y, V388K, N390R, R391C, R391M and R391 and the thermostability is improved by at least 0.5° C. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, D4L, D4C, V5H, N8Q, V9H, S10H, A11P, A11I, A11N, A11G, A11Y, A11C, E12G, E12R, E12K, K13Q, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, G18H, G18Y, G18W, G18F, L31Q, L31H, L31P, L31G, L31S, A34F, G43W, N45D, N45W, N45S, N45F, Q46D, Q46H, G48L, G48V, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, N59C, N59V, N61W, N61L, N61E, N61H, N62A, N62V, N62L, N62C, V67A, V67S, I79K, P88M, P88F, T94H, T101L, T101R, S102R, K104R, A113E, A113Q, D120R, D120A, D120S, N128H, Y143H, Y143R, H145Y, E146R, E146H, E146Y, E146F, M159C, S165Y, S165M, F176H, F176R, F176Y, F176K, L179D, L179N, L179C, L179A, L179R, L179K, L179S, N181C, N188M, A194H, N195H, M196L, D197A, D197S, D197Q, D197G, D197P, S209C, P212K, P212Q, P212R, P212E, A221R, A221K, D224Q, Y231T, Y231V, Y231S, Y231A, S235A, T237P, Y269Q, Y269M, Y269I, Y269F, Y269L, T282H, T282R, T282C, T282V, K295W, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, V302S, V302R, V302T, V302A, V302Q, V302G, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, N311R, N311M, N311I, A312I, A312R, A312M, N313D, D322F, D322G, N323A, S333I, S333R, N334I, T335I, G336C, Q339I, L343C, L343Q, Q344I, N345C, S347R, S347H, S357V, S359H, S359Q, S359F, Q363V, T366N, T366W, N367Y, L368D, S371F, S371W, S371V, N373D, N373I, H374E, H374F, W376A, W376Q, W376D, W376M, H378A, H378T, H378I, H378R, H378C, H378M, P380M, P380D, P380E, P380C, P380V, P380I, P380L, V388E, V388D and R391C and the thermostability is improved by at least 1.0° C. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q, D4L, D4C, V9H, A11P, E12G, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, G18H, G18Y, L31Q, L31H, N45D, G48L, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, N59C, N61W, N61L, I79K, P88M, P88F, T94H, T101L, T101R, S102R, K104R, Y143H, Y143R, H145Y, E146R, E146H, E146Y, E146F, M159C, S165Y, S165M, F176H, F176R, F176Y, F176K, L179D, L179N, L179C, L179A, L179R, N181C, M196L, D197A, D197S, D197Q, D197G, S209C, D224Q, Y231T, Y231V, Y231S, Y231A, S235A, Y269Q, Y269M, K295W, R298Q, R298A, R298E, R298M, R298T, P299W, P299A, P299K, P299F, P299Y, P299Q, V302S, V302R, T307I, T307N, T307R, A312I, D322F, S333I, S333R, T335I, G336C, Q344I, S357V, S359H, L368D, S371F, W376A, H378A, P380M and P380D and the thermostability is improved by at least 1.5° C. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, D4L, Q14K, Q14Y, Q14A, Q14V, Q14W, G18H, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, N61W, I79K, T94H, S102R, Y143H, Y143R, H145Y, E146R, E146H, S165Y, S165M, F176H, F176R, L179D, L179N, L179C, L179A, M196L, D197A, D197S, D197Q, D197G, D224Q, Y231T, Y231V, Y231S, Y231A, Y269Q, R298Q, P299W, P299A, P299K, P299F, V302S, T307I and S333I and the thermostability is improved by at least 2.0° C. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, D4L, Q14K, Q14Y, G18H, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, T94H, S102R, Y143H, H145Y, E146R, S165Y, F176H, F176R, L179D, L179N, L179C, L179A, M196L, D197A, D197S, D197Q, Y231T, Y231V, Y269Q, P299W, P299A, P299K and S333I and the thermostability is improved by at least 2.5° C. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 2 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution A2D, A2Q, A2G, A2W, A2P, A2L or A2Y. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 3 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution S3W, S3F, S3H, S3L, S3G, S3M, S3T or S3P. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 4 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution D4L, D4C, D4Y, D4Q, D4A, D4K or D4P. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 5 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution V5H, V5G or V5P. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 6 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution T6K, T6Q, T6L, T6N, T6R, T6D, T6F or T6H. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 7 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution V7F, V7S, V7C, V7A or V7W. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 8 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N8Q, N8R, N8D, N8F, N8W, N8Y, N8S, N8M, N8L, N8V, N8T, N8I or N8A. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 9 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution V9H, V9R or V9M. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 10 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution S10A, S10H, S10L, S10I, S10D, S10K or S10V. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 11 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution A11P, A11I, A11N, A11G, A11Y, A11C, A11S, A11F, A11M, A11D, A11L, A11H, A11W, A11E, A11V, A11R or A11Q. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 12 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution E12G, E12R, E12K, E12T, E12V, E12W or E12C. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 13 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution K13Q, K13H, K13N, K13L or K13S. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 14 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C or Q14D. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 15 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution V15F, V15L, V15N, V15K or V15H. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 18 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution G18H, G18Y, G18W, G18F, G18C, G18S or G18A. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 19 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution F19H or F19Y. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 31 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I or L31V. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 32 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution T32N or T32D. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 33 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution A33Q, A33H, A33M, A33Y, A33K, A33E, A33R, A33C or A33N. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 34 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution A34F, A34N, A34C, A34L, A34P, A34S or A34Q. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 39 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution A39S. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 43 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution G43W, G43A or G43N. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 44 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution Q44D, Q44N, Q44R, Q44Y or Q44K. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 45 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, N45G, N45P, N45T or N45Y. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 46 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution Q46D, Q46H, Q46C, Q46S, Q46T, Q46N or Q46K. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 48 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution G48L, G48V, G48I, G48Q or G48C. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 50 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E or S50T. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 58 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution E58P, E58K or E58R. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 59 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N59C, N59V, N59D, N59K, N59L or N59S. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 61 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N61W, N61L, N61D, N61E, N61H, N61M, N61Y, N61I, N61T, N61F or N61Q. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 62 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W or N62Q. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 64 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution Y64F or Y64N. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 65 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution K65I or K65L. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 67 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution V67A, V67S, V67F, V67G or V67K. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 68 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution E68W, E68V, E68I, E68A, E68H or E68N. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 79 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution I79K, I79R, I79V or I79A. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 82 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution A82G. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 88 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution P88M, P88F, P88T, P88W or P88Q. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 90 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution D90R. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 94 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution T94H. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 101 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution T101 L or T101R. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 102 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution S102R. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 104 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution K104R or K104H. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 110 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution K110E or K110M. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 112 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution A112G, A112T or A112V. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 113 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution A113E, A113Q, A113L, A113D or A113S. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 116 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution Q116E, Q116A or Q116G. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 119 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N119G, N119S, N119V, N119L, N119C or N119R. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 120 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution D120R, D120A, D120S, D120Y, D120L, D120W, D120T or D120G. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 123 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution T123E, T123Y, T123C, T123H, T123Q, T123K, T123V, T123G, T123R or T123I. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 126 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution K126R, K126A, K126Y, K126L, K126F, K126W, K126E, K126H or K126Q. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 127 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N127P or N127W. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 128 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N128H or N128K. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 129 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution G129M, G129Q, G129A, G129F or G129W. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 131 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N131K or N131R. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 135 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution I135T. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 143 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution Y143H, Y143R or Y143N. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 145 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution H145Y, H145C, H145K, H145A or H145W. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 146 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution E146R, E146H, E146Y, E146F, E146W, E146A, E146K, E146G or E146S. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 159 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution M159C. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 160 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution R160I. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 165 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution S165Y, S165M or S165I. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 168 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution A168I or A168R. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 176 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution F176H, F176R, F176Y, F176K or F176W. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 179 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q or L179W. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 181 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N181C, N181A or N181T. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 188 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N188M, N188E or N188L. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 191 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution Q191I, Q191K, Q191V, Q191R, Q191L or Q191M. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 194 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution A194H, A194R or A194K. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 195 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N195H. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 196 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution M196L or M196I. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 197 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution D197A, D197S, D197Q, D197G, D197P, D197T or D197N. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 205 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution G205C or G205Q. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 209 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution S209N, S209C or S209W. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 212 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution P212A, P212K, P212Q, P212R, P212E, P212S or P212N. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 217 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution K217Q or K217M. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 218 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution Q218H or Q218I. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 221 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution A221R, A221K, A221H, A221Q, A221C or A221N. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 224 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution D224Q. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 231 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution Y231T, Y231V, Y231S, Y231A or Y231C. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 235 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution S235A or S235G. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 237 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution T237P, T237R or T237K. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 238 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N238G. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 242 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution R242I. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 269 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution Y269Q, Y269M, Y269I, Y269F or Y269L. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 280 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution D280S, D280N or D280R. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 282 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution T282M, T282H, T282R, T282C, T282V, T282L, T282E or T282F. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 295 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution K295W, K295T, K295I or K295V. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 298 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, R298P or R298Y. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 299 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, P299G or P299S. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 300 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution G300A or G300R. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 302 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution V302I, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D or V302F. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 305 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution D305W, D305F, D305I or D305M. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 306 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution A306I or A306T. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 307 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307S, T307H, T307E or T307Y. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 311 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N311R, N311M, N311I, N311C or N311V. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 312 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution A312I, A312R, A312M or A312F. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 313 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N313D, N313R, N313I, N313L, N313C, N313G or N313F. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 322 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution D322F, D322G or D322L. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 323 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N323A, N323C, N323Q, N323L, N323G, N323R, N323E, N323S, N323Y or N323P. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 324 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution K324S or K324P. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 333 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution S333I, S333R or S333T. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 334 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N334I, N334A or N334L. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 335 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution T335I or T335A. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 336 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution G336C, G336A or G336E. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 337 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution V337A, V337Q, V337D, V337M, V337E or V337G. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 338 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N338H. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 339 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution Q339I, Q339T or Q339A. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 340 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N340S, N340A or N340C. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 342 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution V342A, V342L, V342I, V342R or V342D. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 343 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution L343C, L343Q, L343I, L343A, L343P, L343S, L343D, L343Y, L343F, L343K, L343H, L343E or L343N. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 344 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution Q344I, Q344R or Q344S. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 345 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N345C, N345A, N345H, N345W, N345Q, N345R, N345I, N345V or N345P. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 346 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution G346H. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 347 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution S347R, S347H, S347I, S347A, S347G, S347K, S347Y, S347W, S347T, S347L or S347F. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 349 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution S349R, S349C, S349A, S349V, S349I, S349F, S349Y, S349T, S349M or S349D. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 350 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N350K or N350A. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 354 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution W354L. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 357 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution S357V or S357Q. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 359 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution S359H, S359Q, S359F, S359R, S359I, S359G, S359Y, S359A, S359P, S359N, S359W or S359E. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 360 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution S360R or S360G. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 363 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution Q363V, Q363R, Q363A, Q363G, Q363H, Q363L, Q363N or Q363F. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 364 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution P364Q, P364H, P364W, P364I or P364L. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 366 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution T366S, T366N, T366W, T366Q, T366C, T366V, T366A, T366S, T366L, T366K, T366R, T366G, T366I or T366Q. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 367 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N367Y, N367P, N367L, N367A, N367F, N367Q, N367W, N367D or N367E. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 368 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution L368D or L368H. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 371 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution S371F, S371W, S371V, S371E, S371R, S371H, S371Q, S371D or S371I. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 373 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N373D, N373I, N373E, N373W, N373Y, N373A, N373H or N373Q. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 374 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution H374E, H374F, H374D, H374T, H374S, H374I, H374L or H374W. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 376 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution W376A, W376Q, W376D, W376M, W376N, W376P, W376H, W376Y, W376L, W376E, W376G, W376F or W376R. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 377 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution A377I, A377V or A377M. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 378 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution H378A, H378T, H378I, H378R, H378C, H378M, H378Q, H378N, H378G, H378L, H378V, H378S, H378Y, H378K, H378D, H378P, H378E or H378F. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 380 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, P380K or P380H. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 385 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution T385F, T385M or T385R. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 388 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution V388E, V388D, V388Y, V388K, V388H, V388L or V388Q. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 390 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution N390R, N390M or N390P. 
     In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 70% (such as at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%) sequence identity to SEQ ID NO: 1 and comprises or consists of a substitution at a position corresponding to position 391 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) and comprises or consists of the substitution R391C, R391M, R391G, R391P, R391H or R391V. 
     The xylanase variants of the present invention may further comprise one or more additional alterations than those described above at one or more (e.g., several) other positions. 
     The amino acid changes may be of a minor nature, that is conservative amino acid substitutions or insertions that do not significantly affect the folding and/or activity of the protein; small deletions, typically of 1-30 amino acids; small amino- or carboxyl-terminal extensions, such as an amino-terminal methionine residue; a small linker peptide of up to 20-25 residues; or a small extension that facilitates purification by changing net charge or another function, such as a poly-histidine tract, an antigenic epitope or a binding domain. 
     Examples of conservative substitutions are within the groups of basic amino acids (arginine, lysine and histidine), acidic amino acids (glutamic acid and aspartic acid), polar amino acids (glutamine and asparagine), hydrophobic amino acids (leucine, isoleucine and valine), aromatic amino acids (phenylalanine, tryptophan and tyrosine), and small amino acids (glycine, alanine, serine, threonine and methionine). Amino acid substitutions that do not generally alter specific activity are known in the art and are described, for example, by H. Neurath and R. L. Hill, 1979, In,  The Proteins , Academic Press, New York. Common substitutions are Ala/Ser, Val/Ile, Asp/Glu, Thr/Ser, Ala/Gly, Ala/Thr, Ser/Asn, Ala/Val, Ser/Gly, Tyr/Phe, Ala/Pro, Lys/Arg, Asp/Asn, Leu/Ile, Leu/Val, Asn/Gln, Gln/Glu, Ala/Glu, and Asp/Gly. Other examples of conservative substitutions are G to A; A to G, S; V to I, L, A, T, S; I to V, L, M; L to I, M, V; M to L, I, V; P to A, S, N; F to Y, W, H; Y to F, W, H; W to Y, F, H; R to K, E, D; K to R, E, D; H to Q, N, S; D to N, E, K, R, Q; E to Q, D, K, R, N; S to T, A; T to S, V, A; C to S, T, A; N to D, Q, H, S; Q to E, N, H, K, R. 
     Alternatively, the amino acid changes are of such a nature that the physico-chemical properties of the polypeptides are altered. For example, amino acid changes may improve the thermal stability of the polypeptide, alter the substrate specificity, change the pH optimum, and the like. 
     Essential amino acids in a polypeptide can be identified according to procedures known in the art, such as site-directed mutagenesis or alanine-scanning mutagenesis (Cunningham and Wells, 1989 , Science  244: 1081-1085). In the latter technique, single alanine mutations are introduced at every residue in the molecule, and the resultant mutant molecules are tested for xylanase activity to identify amino acid residues that are critical to the activity of the molecule. See also, Hilton et al., 1996 , J. Biol. Chem.  271: 4699-4708. The active site of the enzyme or other biological interaction can also be determined by physical analysis of structure, as determined by such techniques as nuclear magnetic resonance, crystallography, electron diffraction, or photoaffinity labeling, in conjunction with mutation of putative contact site amino acids. See, for example, de Vos et al., 1992 , Science  255: 306-312; Smith et al., 1992 , J. Mol. Biol.  224: 899-904; Wlodaver et al., 1992 , FEBS Lett.  309: 59-64. The identity of essential amino acids can also be inferred from an alignment with a related polypeptide. 
     In one embodiment, the variant comprises a substitution at 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 positions. 
     In one embodiment of any part of the second aspect, the thermostability may be determined as described in Example 2 herein. 
     Granules Comprising Xylanase Variants 
     In a third aspect, the present invention relates to granules comprising the xylanase variants as disclosed in any part of the second aspect of the invention. 
     Thus in one embodiment of the third aspect, the invention relates to granules comprising xylanase variants having xylanase activity, wherein the variant has at least 70% sequence identity to SEQ ID NO: 1 and comprises an alteration at one or more positions corresponding to positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 31, 32, 33, 34, 39, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 64, 65, 67, 68, 79, 82, 88, 90, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 127, 128, 129, 131, 135, 143, 145, 146, 159, 160, 165, 168, 176,179, 181, 188, 191, 194,195, 196, 197, 205, 209, 212, 217, 218, 221, 224, 231, 235, 237, 238, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 338, 339, 340, 342, 343, 344, 345, 346, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1. 
     In an embodiment, the variant has a sequence identity of at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%, but less than 100%, to SEQ ID NO: 1. 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the number of alterations is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In one embodiment of the third aspect, the invention relates to granules comprising xylanase variants having xylanase activity, wherein the variant has at least 70% sequence identity to SEQ ID NO: 1 and comprises a substitution at one or more positions corresponding to positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 31, 32, 33, 34, 39, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 64, 65, 67, 68, 79, 82, 88, 90, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 127, 128,129, 131, 135, 143, 145, 146, 159, 160, 165, 168, 176, 179, 181,188, 191, 194, 195, 196, 197, 205, 209, 212, 217, 218, 221, 224, 231, 235, 237, 238, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 338, 339, 340, 342, 343, 344, 345, 346, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1. 
     In an embodiment, the variant has a sequence identity of at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%, but less than 100%, to SEQ ID NO: 1. 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the substitution is selected from the group consisting of A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W and Y, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. 
     In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In one embodiment of the third aspect, the invention relates to granules comprising xylanase variants having xylanase activity, wherein the variant has at least 70% sequence identity to SEQ ID NO: 1 and comprises one or more substitutions selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, A2L, A2Y, S3W, S3F, S3H, S3L, S3G, S3M, S3T, S3P, D4L, D4C, D4Y, D4Q, D4A, D4K, D4P, V5H, V5G, V5P, T6K, T6Q, T6L, T6N, T6R, T6D, T6F, T6H, V7F, V7S, V7C, V7A, V7W, N8Q, N8R, N8D, N8F, N8W, N8Y, N8S, N8M, N8L, N8V, N8T, N8I, N8A, V9H, V9R, V9M, S10A, S10H, S10L, S10I, S10D, S10K, S10V, A11P, A11I, A11N, A11G, A11Y, A11C, A11S, A11F, A11M, A11D, A11L, A11H, A11W, A11E, A11V, A11R, A11Q, E12G, E12R, E12K, E12T, E12V, E12W, E12C, K13Q, K13H, K13N, K13L, K13S, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, Q14D, V15F, V15L, V15N, V15K, V15H, G18H, G18Y, G18W, G18F, G18C, G18S, G18A, F19H, F19Y, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, L31V, T32N, T32D, A33Q, A33H, A33M, A33Y, A33K, A33E, A33R, A33C, A33N, A34F, A34N, A34C, A34L, A34P, A34S, A34Q, A39S, G43W, G43A, G43N, Q44D, Q44N, Q44R, Q44Y, Q44K, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, N45G, N45P, N45T, N45Y, Q46D, Q46H, Q46C, Q46S, Q46T, Q46N, Q46K, G48L, G48V, G48I, G48Q, G48C, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, S50T, E58P, E58K, E58R, N59C, N59V, N59D, N59K, N59L, N59S, N61W, N61L, N61D, N61E, N61H, N61M, N61Y, N61I, N61T, N61F, N61Q, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, N62Q, Y64F, Y64N, K65I, K65L, V67A, V67S, V67F, V67G, V67K, E68W, E68V, E68I, E68A, E68H, E68N, I79K, I79R, I79V, I79A, A82G, P88M, P88F, P88T, P88W, P88Q, D90R, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A112G, A112T, A112V, A113E, A113Q, A113L, A113D, A113S, Q116E, Q116A, Q116G, N119G, N119S, N119V, N119L, N119C, N119R, D120R, D120A, D120S, D120Y, D120L, D120W, D120T, D120G, T123E, T123Y, T123C, T123H, T123Q, T123K, T123V, T123G, T123R, T123I, K126R, K126A, K126Y, K126L, K126F, K126W, K126E, K126H, K126Q, N127P, N127W, N128H, N128K, G129M, G129Q, G129A, G129F, G129W, N131K, N131R, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, H145W, E146R, E146H, E146Y, E146F, E146W, E146A, E146K, E146G, E146S, M159C, R160I, S165Y, S165M, S165I, A168I, A168R, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N181A, N181T, N188M, N188E, N188L, Q191I, Q191K, Q191V, Q191R, Q191L, Q191M, A194H, A194R, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, G205C, G205Q, S209N, S209C, S209W, P212A, P212K, P212Q, P212R, P212E, P212S, P212N, K217Q, K217M, Q218H, Q218I, A221R, A221K, A221H, A221Q, A221C, A221N, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, N238G, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, D280N, D280R, T282M, T282H, T282R, T282C, T282V, T282L, T282E, T282F, K295W, K295T, K295I, K295V, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, R298P, R298Y, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, P299G, P299S, G300A, G300R, V302I, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, V302F, D305W, D305F, D305I, D305M, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307S, T307H, T307E, T307Y, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, N313L, N313C, N313G, N313F, D322F, D322G, D322L, N323A, N323C, N323Q, N323L, N323G, N323R, N323E, N323S, N323Y, N323P, K324S, K324P, S333I, S333R, S333T, N334I, N334A, N334L, T335I, T335A, G336C, G336A, G336E, V337A, V337Q, V337D, V337M, V337E, V337G, N338H, Q339I, Q339T, Q339A, N340S, N340A, N340C, V342A, V342L, V342I, V342R, V342D, L343C, L343Q, L343I, L343A, L343P, L343S, L343D, L343Y, L343F, L343K, L343H, L343E, L343N, Q344I, Q344R, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, N345I, N345V, N345P, G346H, S347R, S347H, S347I, S347A, S347G, S347K, S347Y, S347W, S347T, S347L, S347F, S349R, S349C, S349A, S349V, S349I, S349F, S349Y, S349T, S349M, S349D, N350K, N350A, W354L, S357V, S357Q, S359H, S359Q, S359F, S359R, S359I, S359G, S359Y, S359A, S359P, S359N, S359W, S359E, S360R, S360G, Q363V, Q363R, Q363A, Q363G, Q363H, Q363L, Q363N, Q363F, P364Q, P364H, P364W, P364I, P364L, T366S, T366N, T366W, T366Q, T366C, T366V, T366A, T366S, T366L, T366K, T366R, T366G, T366I, T366Q, N367Y, N367P, N367L, N367A, N367F, N367Q, N367W, N367D, N367E, L368D, L368H, S371F, S371W, S371V, S371E, S371R, S371H, S371Q, S371D, S371I, N373D, N373I, N373E, N373W, N373Y, N373A, N373H, N373Q, H374E, H374F, H374D, H374T, H374S, H374I, H374L, H374W, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, W376Y, W376L, W376E, W376G, W376F, W376R, A377I, A377V, A377M, H378A, H378T, H378I, H378R, H378C, H378M, H378Q, H378N, H378G, H378L, H378V, H378S, H378Y, H378K, H378D, H378P, H378E, H378F, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, P380K, P380H, T385F, T385M, T385R, V388E, V388D, V388Y, V388K, V388H, V388L, V388Q, N390R, N390M, N390P, R391C, R391M, R391G, R391P, R391H and R391V (wherein the position corresponds to the position of SEQ ID NO: 1). 
     In an embodiment, the variant has a sequence identity of at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%, but less than 100%, to SEQ ID NO: 1. 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In one embodiment of the third aspect, the invention relates to granules comprising xylanase variants having xylanase activity, wherein the variant has at least 70% (such as at least 75%, e.g at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%) sequence identity to SEQ ID NO: 1 and comprises one or more substitutions selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, A2L, A2Y, S3W, S3F, S3H, S3L, S3G, S3M, S3T, S3P, D4L, D4C, D4Y, D4Q, D4A, D4K, D4P, V5H, V5G, V5P, T6Q, T6L, T6R, T6D, T6F, T6H, V7F, V7S, V7C, V7A, V7W, N8Q, N8F, N8W, N8Y, N8S, N8M, N8L, N8V, N8T, N8I, N8A, V9H, V9R, V9M, S10H, S10L, S10I, S10D, S10K, S10V, A11P, A11I, A11N, A11G, A11Y, A11C, A11F, A11M, A11D, A11L, A11H, A11W, A11E, A11V, A11R, A11Q, E12G, E12R, E12K, E12T, E12V, E12W, E12C, K13Q, K13H, K13N, K13L, K13S, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, Q14D, V15F, V15N, V15K, V15H, G18H, G18Y, G18W, G18F, G18C, G18S, G18A, F19H, F19Y, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, L31V, T32N, T32D, A33Q, A33H, A33M, A33Y, A33K, A33R, A33C, A33N, A34F, A34C, A34L, A34Q, A39S, G43W, G43A, G43N, Q44R, Q44Y, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, N45G, N45P, N45T, N45Y, Q46D, Q46H, Q46C, Q46S, Q46T, Q46N, Q46K, G48L, G48V, G48I, G48Q, G48C, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, E58K, E58R, N59C, N59V, N59K, N59L, N59S, N61W, N61L, N61E, N61H, N61M, N61Y, N61I, N61T, N61F, N61Q, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, Y64F, Y64N, K65I, K65L, V67A, V67S, V67F, V67G, V67K, E68W, E68V, E68I, E68H, E68N, I79K, I79R, I79V, I79A, A82G, P88M, P88F, P88T, P88W, P88Q, D90R, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A112V, A113E, A113Q, A113L, A113S, Q116E, Q116A, Q116G, N119G, N119S, N119V, N119L, N119C, N119R, D120R, D120A, D120S, D120Y, D120L, D120W, D120T, T123E, T123Y, T123C, T123H, T123Q, T123K, T123V, T123G, T123R, T123I, K126A, K126Y, K126L, K126F, K126W, K126E, K126H, K126Q, N127P, N127W, N128H, N128K, G129M, G129Q, G129A, G129F, G129W, N131K, N131R, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, H145W, E146R, E146H, E146Y, E146F, E146W, E146A, E146K, E146G, E146S, M159C, R160I, S165Y, S165M, S165I, A168I, A168R, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N181T, N188M, N188E, N188L, Q191I, Q191V, Q191R, Q191L, Q191M, A194H, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, G205C, G205Q, S209C, S209W, P212K, P212Q, P212R, P212E, P212N, K217Q, K217M, Q218H, Q218I, A221R, A221K, A221H, A221Q, A221C, A221N, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, N238G, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, D280R, T282H, T282R, T282C, T282V, T282E, T282F, K295W, K295T, K295I, K295V, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, R298P, R298Y, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, P299G, P299S, G300A, G300R, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, V302F, D305W, D305F, D305I, D305M, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307H, T307E, T307Y, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, N313L, N313C, N313G, N313F, D322F, D322G, D322L, N323A, N323C, N323Q, N323L, N323G, N323R, N323E, N323S, N323Y, N323P, K324S, K324P, S333I, S333R, N334I, N334L, T335I, G336C, V337Q, V337D, V337M, V337E, V337G, N338H, Q339I, Q339T, Q339A, N340A, N340C, V342L, V342I, V342R, V342D, L343C, L343Q, L343A, L343P, L343S, L343D, L343Y, L343K, L343H, L343E, L343N, Q344I, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, N345I, N345V, N345P, G346H, S347R, S347H, S347I, S347G, S347Y, S347W, S347L, S347F, S349R, S349C, S349V, S349I, S349F, S349Y, S349T, S349M, S349D, N350A, W354L, S357V, S357Q, S359H, S359Q, S359F, S359R, S359I, S359Y, S359A, S359P, S359W, S359E, S360G, Q363V, Q363R, Q363G, Q363H, Q363L, Q363N, Q363F, P364Q, P364H, P364W, P364I, P364L, T366S, T366N, T366W, T366Q, T366C, T366V, T366L, T366K, T366R, T366G, T366I, T366Q, N367Y, N367L, N367F, N367Q, N367W, L368D, L368H, S371F, S371W, S371V, S371E, S371R, S371H, S371Q, S371D, S371I, N373D, N373I, N373W, N373Y, N373A, N373H, N373Q, H374E, H374F, H374D, H374I, H374L, H374W, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, W376Y, W376L, W376E, W376G, W376F, W376R, A377I, A377V, A377M, H378A, H378T, H378I, H378R, H378C, H378M, H378N, H378G, H378L, H378V, H378S, H378Y, H378K, H378D, H378P, H378E, H378F, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, P380K, P380H, T385F, T385M, T385R, V388E, V388D, V388Y, V388K, V388H, V388L, V388Q, N390R, N390M, N390P, R391C, R391M, R391P, R391H and R391V, wherein the variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) (wherein the position corresponds to the position of SEQ ID NO: 1). 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, S3W, S3F, S3H, S3L, D4L, D4C, V5H, T6Q, T6L, V7F, V7S, V7C, V7A, N8Q, N8F, N8W, N8Y, N8S, N8M, N8L, V9H, V9R, V9M, S10H, S10L, S10I, A11P, A11I, A11N, A11G, A11Y, A11C, A11F, A11M, A11D, A11L, A11H, A11W, A11E, E12G, E12R, E12K, E12T, E12V, E12W, K13Q, K13H, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, V15F, V15N, V15K, G18H, G18Y, G18W, G18F, G18C, G18S, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, T32N, T32D, A33Q, A33H, A33M, A33Y, A34F, A34N, G43W, G43A, G43N, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, Q46D, Q46H, Q46C, Q46S, Q46T, G48L, G48V, G48I, G48Q, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, E58K, N59C, N59V, N59K, N61W, N61L, N61E, N61H, N61M, N61Y, N61I, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, K65I, K65L, V67A, V67S, V67F, E68W, E68V, E68I, I79K, I79R, A82G, P88M, P88F, P88T, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A113E, A113Q, A113L, Q116E, Q116A, Q116G, N119G, N119S, D120R, D120A, D120S, D120Y, D120L, T123E, T123Y, T123C, T123H, N128H, G129M, G129Q, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, E146R, E146H, E146Y, E146F, E146W, E146A, M159C, R160I, S165Y, S165M, A168I, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N188M, Q191I, Q191V, A194H, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, S209C, P212K, P212Q, P212R, P212E, P212N, K217Q, Q218H, A221R, A221K, A221H, A221Q, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, T282H, T282R, T282C, T282V, K295W, K295T, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, G300A, G300R, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, D305W, D305F, D305I, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307H, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, D322F, D322G, N323A, N323C, K324S, K324P, S333I, S333R, N334I, T335I, G336C, V337Q, Q339I, V342L, L343C, L343Q, L343A, L343P, L343S, L343D, L343Y, Q344I, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, S347R, S347H, S347I, S347G, S349R, S349C, S349V, W354L, S357V, S359H, S359Q, S359F, S359R, S359I, S359Y, S359A, S359P, Q363V, Q363R, Q363G, P364Q, P364H, T366N, T366W, T366Q, T366C, T366V, N367Y, N367L, N367F, L368D, L368H, S371F, S371W, S371V, S371E, N373D, N373I, N373W, H374E, H374F, H374D, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, A377I, H378A, H378T, H378I, H378R, H378C, H378M, H378N, H378G, H378L, H378V, H378S, H378Y, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, T385F, T385M, V388E, V388D, V388Y, V388K, N390R, R391C, R391M and R391 and the thermostability is improved by at least 0.5° C. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, D4L, D4C, V5H, N8Q, V9H, S10H, A11P, A11I, A11N, A11G, A11Y, A11C, E12G, E12R, E12K, K13Q, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, G18H, G18Y, G18W, G18F, L31Q, L31H, L31P, L31G, L31S, A34F, G43W, N45D, N45W, N45S, N45F, Q46D, Q46H, G48L, G48V, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, N59C, N59V, N61W, N61L, N61E, N61H, N62A, N62V, N62L, N62C, V67A, V67S, I79K, P88M, P88F, T94H, T101L, T101R, S102R, K104R, A113E, A113Q, D120R, D120A, D120S, N128H, Y143H, Y143R, H145Y, E146R, E146H, E146Y, E146F, M159C, S165Y, S165M, F176H, F176R, F176Y, F176K, L179D, L179N, L179C, L179A, L179R, L179K, L179S, N181C, N188M, A194H, N195H, M196L, D197A, D197S, D197Q, D197G, D197P, S209C, P212K, P212Q, P212R, P212E, A221R, A221K, D224Q, Y231T, Y231V, Y231S, Y231A, S235A, T237P, Y269Q, Y269M, Y269I, Y269F, Y269L, T282H, T282R, T282C, T282V, K295W, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, V302S, V302R, V302T, V302A, V302Q, V302G, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, N311R, N311M, N311I, A312I, A312R, A312M, N313D, D322F, D322G, N323A, S333I, S333R, N334I, T335I, G336C, Q339I, L343C, L343Q, Q344I, N345C, S347R, S347H, S357V, S359H, S359Q, S359F, Q363V, T366N, T366W, N367Y, L368D, S371F, S371W, S371V, N373D, N373I, H374E, H374F, W376A, W376Q, W376D, W376M, H378A, H378T, H378I, H378R, H378C, H378M, P380M, P380D, P380E, P380C, P380V, P380I, P380L, V388E, V388D and R391C and the thermostability is improved by at least 1.0° C. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q, D4L, D4C, V9H, A11P, E12G, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, G18H, G18Y, L31Q, L31H, N45D, G48L, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, N59C, N61W, N61L, I79K, P88M, P88F, T94H, T101L, T101R, S102R, K104R, Y143H, Y143R, H145Y, E146R, E146H, E146Y, E146F, M159C, S165Y, S165M, F176H, F176R, F176Y, F176K, L179D, L179N, L179C, L179A, L179R, N181C, M196L, D197A, D197S, D197Q, D197G, S209C, D224Q, Y231T, Y231V, Y231S, Y231A, S235A, Y269Q, Y269M, K295W, R298Q, R298A, R298E, R298M, R298T, P299W, P299A, P299K, P299F, P299Y, P299Q, V302S, V302R, T307I, T307N, T307R, A312I, D322F, S333I, S333R, T335I, G336C, Q344I, S357V, S359H, L368D, S371F, W376A, H378A, P380M and P380D and the thermostability is improved by at least 1.5° C. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, D4L, Q14K, Q14Y, Q14A, Q14V, Q14W, G18H, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, N61W, I79K, T94H, S102R, Y143H, Y143R, H145Y, E146R, E146H, S165Y, S165M, F176H, F176R, L179D, L179N, L179C, L179A, M196L, D197A, D197S, D197Q, D197G, D224Q, Y231T, Y231V, Y231S, Y231A, Y269Q, R298Q, P299W, P299A, P299K, P299F, V302S, T307I and S333I and the thermostability is improved by at least 2.0° C. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, D4L, Q14K, Q14Y, G18H, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, T94H, S102R, Y143H, H145Y, E146R, S165Y, F176H, F176R, L179D, L179N, L179C, L179A, M196L, D197A, D197S, D197Q, Y231T, Y231V, Y269Q, P299W, P299A, P299K and S333I and the thermostability is improved by at least 2.5° C. 
     Liquid Formulations Comprising Polypeptides Having Alpha-Galactosidase Activity 
     In a fourth aspect, the present invention relates to liquid formulations comprising the xylanase variants as disclosed in any part of the second aspect of the invention. 
     Thus, in one embodiment of the fourth aspect, the invention relates to liquid formulations comprising:
         (A) 0.001% to 25% w/w of xylanase variants having xylanase activity, wherein the variant has at least 70% sequence identity to SEQ ID NO: 1 and comprises an alteration at one or more positions corresponding to positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 31, 32, 33, 34, 39, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 64, 65, 67, 68, 79, 82, 88, 90, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 127, 128, 129, 131, 135, 143, 145, 146, 159, 160, 165, 168, 176, 179, 181, 188, 191, 194, 195, 196, 197, 205, 209, 212, 217, 218, 221, 224, 231, 235, 237, 238, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 338, 339, 340, 342, 343, 344, 345, 346, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1; and   (B) water.       

     In an embodiment, the variant has a sequence identity of at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%, but less than 100%, to SEQ ID NO: 1. 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the number of alterations is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In one embodiment, the liquid formulation comprises 20% to 80% w/w of polyol. 
     In one embodiment, the liquid formulation comprises 0.001% to 2.0% w/w preservative. 
     Thus, in one embodiment of the fourth aspect, the invention relates to liquid formulations comprising:
         (A) 0.001% to 25% w/w of xylanase variants having xylanase activity, wherein the variant has at least 70% sequence identity to SEQ ID NO: 1 and comprises a substitution at one or more positions corresponding to positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 31, 32, 33, 34, 39, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 64, 65, 67, 68, 79, 82, 88, 90, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 127, 128, 129, 131, 135, 143, 145, 146, 159, 160, 165, 168, 176, 179, 181, 188, 191, 194, 195, 196, 197, 205, 209, 212, 217, 218, 221, 224, 231, 235, 237, 238, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 338, 339, 340, 342, 343, 344, 345, 346, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1; and   (B) water.       

     In an embodiment, the variant has a sequence identity of at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%, but less than 100%, to SEQ ID NO: 1. 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the substitution is selected from the group consisting of A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W and Y, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. 
     In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In one embodiment, the liquid formulation comprises 20% to 80% w/w of polyol. 
     In one embodiment, the liquid formulation comprises 0.001% to 2.0% w/w preservative. 
     Thus, in one embodiment of the fourth aspect, the invention relates to liquid formulations comprising:
         (A) 0.001% to 25% w/w of xylanase variants having xylanase activity, wherein the variant has at least 70% sequence identity to SEQ ID NO: 1 and comprises a substitution at one or more positions corresponding to positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 31, 32, 33, 34, 39, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 64, 65, 67, 68, 79, 82, 88, 90, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 127, 128, 129, 131, 135, 143, 145, 146, 159, 160, 165, 168, 176, 179, 181, 188, 191, 194, 195, 196, 197, 205, 209, 212, 217, 218, 221, 224, 231, 235, 237, 238, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 338, 339, 340, 342, 343, 344, 345, 346, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1;   (B) 20% to 80% w/w of polyol;   (C) 0.001% to 2.0% w/w preservative; and   (D) water.       

     In an embodiment, the variant has a sequence identity of at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%, but less than 100%, to SEQ ID NO: 1. 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the substitution is selected from the group consisting of A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W and Y, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. 
     In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     Thus, in one embodiment of the fourth aspect, the invention relates to liquid formulations comprising:
         (A) 0.001% to 25% w/w of xylanase variants having xylanase activity, wherein the variant has at least 70% sequence identity to SEQ ID NO: 1 and comprises one or more substitutions selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, A2L, A2Y, S3W, S3F, S3H, S3L, S3G, S3M, S3T, S3P, D4L, D4C, D4Y, D4Q, D4A, D4K, D4P, V5H, V5G, V5P, T6K, T6Q, T6L, T6N, T6R, T6D, T6F, T6H, V7F, V7S, V7C, V7A, V7W, N8Q, N8R, N8D, N8F, N8W, N8Y, N8S, N8M, N8L, N8V, N8T, N8I, N8A, V9H, V9R, V9M, S10A, S10H, S10L, S10I, S10D, S10K, S10V, A11P, A11I, A11N, A11G, A11Y, A11C, A11S, A11F, A11M, A11D, A11L, A11H, A11W, A11E, A11V, A11R, A11Q, E12G, E12R, E12K, E12T, E12V, E12W, E12C, K13Q, K13H, K13N, K13L, K13S, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, Q14D, V15F, V15L, V15N, V15K, V15H, G18H, G18Y, G18W, G18F, G18C, G18S, G18A, F19H, F19Y, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, L31V, T32N, T32D, A33Q, A33H, A33M, A33Y, A33K, A33E, A33R, A33C, A33N, A34F, A34N, A34C, A34L, A34P, A34S, A34Q, A39S, G43W, G43A, G43N, Q44D, Q44N, Q44R, Q44Y, Q44K, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, N45G, N45P, N45T, N45Y, Q46D, Q46H, Q46C, Q46S, Q46T, Q46N, Q46K, G48L, G48V, G48I, G48Q, G48C, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, S50T, E58P, E58K, E58R, N59C, N59V, N59D, N59K, N59L, N59S, N61W, N61L, N61D, N61E, N61H, N61M, N61Y, N61I, N61T, N61F, N61Q, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, N62Q, Y64F, Y64N, K65I, K65L, V67A, V67S, V67F, V67G, V67K, E68W, E68V, E68I, E68A, E68H, E68N, I79K, I79R, I79V, I79A, A82G, P88M, P88F, P88T, P88W, P88Q, D90R, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A112G, A112T, A112V, A113E, A113Q, A113L, A113D, A113S, Q116E, Q116A, Q116G, N119G, N119S, N119V, N119L, N119C, N119R, D120R, D120A, D120S, D120Y, D120L, D120W, D120T, D120G, T123E, T123Y, T123C, T123H, T123Q, T123K, T123V, T123G, T123R, T123I, K126R, K126A, K126Y, K126L, K126F, K126W, K126E, K126H, K126Q, N127P, N127W, N128H, N128K, G129M, G129Q, G129A, G129F, G129W, N131K, N131R, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, H145W, E146R, E146H, E146Y, E146F, E146W, E146A, E146K, E146G, E146S, M159C, R160I, S165Y, S165M, S165I, A168I, A168R, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N181A, N181T, N188M, N188E, N188L, Q191I, Q191K, Q191V, Q191R, Q191L, Q191M, A194H, A194R, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, G205C, G205Q, S209N, S209C, S209W, P212A, P212K, P212Q, P212R, P212E, P212S, P212N, K217Q, K217M, Q218H, Q218I, A221R, A221K, A221H, A221Q, A221C, A221N, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, N238G, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, D280N, D280R, T282M, T282H, T282R, T282C, T282V, T282L, T282E, T282F, K295W, K295T, K295I, K295V, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, R298P, R298Y, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, P299G, P299S, G300A, G300R, V302I, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, V302F, D305W, D305F, D305I, D305M, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307S, T307H, T307E, T307Y, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, N313L, N313C, N313G, N313F, D322F, D322G, D322L, N323A, N323C, N323Q, N323L, N323G, N323R, N323E, N323S, N323Y, N323P, K324S, K324P, S333I, S333R, S333T, N334I, N334A, N334L, T335I, T335A, G336C, G336A, G336E, V337A, V337Q, V337D, V337M, V337E, V337G, N338H, Q339I, Q339T, Q339A, N340S, N340A, N340C, V342A, V342L, V342I, V342R, V342D, L343C, L343Q, L343I, L343A, L343P, L343S, L343D, L343Y, L343F, L343K, L343H, L343E, L343N, Q344I, Q344R, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, N345I, N345V, N345P, G346H, S347R, S347H, S347I, S347A, S347G, S347K, S347Y, S347W, S347T, S347L, S347F, S349R, S349C, S349A, S349V, S349I, S349F, S349Y, S349T, S349M, S349D, N350K, N350A, W354L, S357V, S357Q, S359H, S359Q, S359F, S359R, S359I, S359G, S359Y, S359A, S359P, S359N, S359W, S359E, S360R, S360G, Q363V, Q363R, Q363A, Q363G, Q363H, Q363L, Q363N, Q363F, P364Q, P364H, P364W, P364I, P364L, T366S, T366N, T366W, T366Q, T366C, T366V, T366A, T366S, T366L, T366K, T366R, T366G, T366I, T366Q, N367Y, N367P, N367L, N367A, N367F, N367Q, N367W, N367D, N367E, L368D, L368H, S371F, S371W, S371V, S371E, S371R, S371H, S371Q, S371D, S371I, N373D, N373I, N373E, N373W, N373Y, N373A, N373H, N373Q, H374E, H374F, H374D, H374T, H374S, H374I, H374L, H374W, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, W376Y, W376L, W376E, W376G, W376F, W376R, A377I, A377V, A377M, H378A, H378T, H378I, H378R, H378C, H378M, H378Q, H378N, H378G, H378L, H378V, H378S, H378Y, H378K, H378D, H378P, H378E, H378F, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, P380K, P380H, T385F, T385M, T385R, V388E, V388D, V388Y, V388K, V388H, V388L, V388Q, N390R, N390M, N390P, R391C, R391M, R391G, R391P, R391H and R391V (wherein the position corresponds to the position of SEQ ID NO: 1); and   (B) water.       

     In an embodiment, the variant has a sequence identity of at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%, but less than 100%, to SEQ ID NO: 1. 
     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In one embodiment, the liquid formulation comprises 20% to 80% w/w of polyol. 
     In one embodiment, the liquid formulation comprises 0.001% to 2.0% w/w preservative. 
     Thus, in one embodiment of the fourth aspect, the invention relates to liquid formulations comprising:
         (A) 0.001% to 25% w/w of xylanase variants having xylanase activity, wherein the variant has at least 70% (such as at least 75%, e.g at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%) sequence identity to SEQ ID NO: 1 and comprises one or more substitutions selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, A2L, A2Y, S3W, S3F, S3H, S3L, S3G, S3M, S3T, S3P, D4L, D4C, D4Y, D4Q, D4A, D4K, D4P, V5H, V5G, V5P, T6Q, T6L, T6R, T6D, T6F, T6H, V7F, V7S, V7C, V7A, V7W, N8Q, N8F, N8W, N8Y, N8S, N8M, N8L, N8V, N8T, N8I, N8A, V9H, V9R, V9M, S10H, S10L, S10I, S10D, S10K, S10V, A11P, A11I, A11N, A11G, A11Y, A11C, A11F, A11M, A11D, A11L, A11H, A11W, A11E, A11V, A11R, A11Q, E12G, E12R, E12K, E12T, E12V, E12W, E12C, K13Q, K13H, K13N, K13L, K13S, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, Q14D, V15F, V15N, V15K, V15H, G18H, G18Y, G18W, G18F, G18C, G18S, G18A, F19H, F19Y, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, L31V, T32N, T32D, A33Q, A33H, A33M, A33Y, A33K, A33R, A33C, A33N, A34F, A34C, A34L, A34Q, A39S, G43W, G43A, G43N, Q44R, Q44Y, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, N45G, N45P, N45T, N45Y, Q46D, Q46H, Q46C, Q46S, Q46T, Q46N, Q46K, G48L, G48V, G48I, G48Q, G48C, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, E58K, E58R, N59C, N59V, N59K, N59L, N59S, N61W, N61L, N61E, N61H, N61M, N61Y, N61I, N61T, N61F, N61Q, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, Y64F, Y64N, K65I, K65L, V67A, V67S, V67F, V67G, V67K, E68W, E68V, E68I, E68H, E68N, I79K, I79R, I79V, I79A, A82G, P88M, P88F, P88T, P88W, P88Q, D90R, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A112V, A113E, A113Q, A113L, A113S, Q116E, Q116A, Q116G, N119G, N119S, N119V, N119L, N119C, N119R, D120R, D120A, D120S, D120Y, D120L, D120W, D120T, T123E, T123Y, T123C, T123H, T123Q, T123K, T123V, T123G, T123R, T123I, K126A, K126Y, K126L, K126F, K126W, K126E, K126H, K126Q, N127P, N127W, N128H, N128K, G129M, G129Q, G129A, G129F, G129W, N131K, N131R, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, H145W, E146R, E146H, E146Y, E146F, E146W, E146A, E146K, E146G, E146S, M159C, R160I, S165Y, S165M, S165I, A168I, A168R, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N181T, N188M, N188E, N188L, Q191I, Q191V, Q191R, Q191L, Q191M, A194H, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, G205C, G205Q, S209C, S209W, P212K, P212Q, P212R, P212E, P212N, K217Q, K217M, Q218H, Q218I, A221R, A221K, A221H, A221Q, A221C, A221N, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, N238G, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, D280R, T282H, T282R, T282C, T282V, T282E, T282F, K295W, K295T, K295I, K295V, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, R298P, R298Y, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, P299G, P299S, G300A, G300R, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, V302F, D305W, D305F, D305I, D305M, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307H, T307E, T307Y, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, N313L, N313C, N313G, N313F, D322F, D322G, D322L, N323A, N323C, N323Q, N323L, N323G, N323R, N323E, N323S, N323Y, N323P, K324S, K324P, S333I, S333R, N334I, N334L, T335I, G336C, V337Q, V337D, V337M, V337E, V337G, N338H, Q339I, Q339T, Q339A, N340A, N340C, V342L, V342I, V342R, V342D, L343C, L343Q, L343A, L343P, L343S, L343D, L343Y, L343K, L343H, L343E, L343N, Q344I, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, N345I, N345V, N345P, G346H, S347R, S347H, S347I, S347G, S347Y, S347W, S347L, S347F, S349R, S349C, S349V, S349I, S349F, S349Y, S349T, S349M, S349D, N350A, W354L, S357V, S357Q, S359H, S359Q, S359F, S359R, S359I, S359Y, S359A, S359P, S359W, S359E, S360G, Q363V, Q363R, Q363G, Q363H, Q363L, Q363N, Q363F, P364Q, P364H, P364W, P364I, P364L, T366S, T366N, T366W, T366Q, T366C, T366V, T366L, T366K, T366R, T366G, T366I, T366Q, N367Y, N367L, N367F, N367Q, N367W, L368D, L368H, S371F, S371W, S371V, S371E, S371R, S371H, S371Q, S371D, S371I, N373D, N373I, N373W, N373Y, N373A, N373H, N373Q, H374E, H374F, H374D, H374I, H374L, H374W, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, W376Y, W376L, W376E, W376G, W376F, W376R, A377I, A377V, A377M, H378A, H378T, H378I, H378R, H378C, H378M, H378N, H378G, H378L, H378V, H378S, H378Y, H378K, H378D, H378P, H378E, H378F, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, P380K, P380H, T385F, T385M, T385R, V388E, V388D, V388Y, V388K, V388H, V388L, V388Q, N390R, N390M, N390P, R391C, R391M, R391P, R391H and R391V, wherein the variant has improved thermostability compared to the parent xylanase (e.g. SEQ ID NO: 1) (wherein the position corresponds to the position of SEQ ID NO: 1);   (B) 20% to 80% w/w of polyol;   (C) 0.001% to 2.0% w/w preservative; and   (D) water.       

     In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase, preferably SEQ ID NO: 1, of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C. 
     In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, S3W, S3F, S3H, S3L, D4L, D4C, V5H, T6Q, T6L, V7F, V7S, V7C, V7A, N8Q, N8F, N8W, N8Y, N8S, N8M, N8L, V9H, V9R, V9M, S10H, S10L, S10I, A11P, A11I, A11N, A11G, A11Y, A11C, A11F, A11M, A11D, A11L, A11H, A11W, A11E, E12G, E12R, E12K, E12T, E12V, E12W, K13Q, K13H, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, V15F, V15N, V15K, G18H, G18Y, G18W, G18F, G18C, G18S, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, T32N, T32D, A33Q, A33H, A33M, A33Y, A34F, A34N, G43W, G43A, G43N, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, Q46D, Q46H, Q46C, Q46S, Q46T, G48L, G48V, G48I, G48Q, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, E58K, N59C, N59V, N59K, N61W, N61L, N61E, N61H, N61M, N61Y, N61I, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, K65I, K65L, V67A, V67S, V67F, E68W, E68V, E68I, I79K, I79R, A82G, P88M, P88F, P88T, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A113E, A113Q, A113L, Q116E, Q116A, Q116G, N119G, N119S, D120R, D120A, D120S, D120Y, D120L, T123E, T123Y, T123C, T123H, N128H, G129M, G129Q, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, E146R, E146H, E146Y, E146F, E146W, E146A, M159C, R160I, S165Y, S165M, A168I, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N188M, Q191I, Q191V, A194H, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, S209C, P212K, P212Q, P212R, P212E, P212N, K217Q, Q218H, A221R, A221K, A221H, A221Q, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, T282H, T282R, T282C, T282V, K295W, K295T, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, G300A, G300R, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, D305W, D305F, D305I, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307H, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, D322F, D322G, N323A, N323C, K324S, K324P, S333I, S333R, N334I, T335I, G336C, V337Q, Q339I, V342L, L343C, L343Q, L343A, L343P, L343S, L343D, L343Y, Q344I, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, S347R, S347H, S347I, S347G, S349R, S349C, S349V, W354L, S357V, S359H, S359Q, S359F, S359R, S359I, S359Y, S359A, S359P, Q363V, Q363R, Q363G, P364Q, P364H, T366N, T366W, T366Q, T366C, T366V, N367Y, N367L, N367F, L368D, L368H, S371F, S371W, S371V, S371E, N373D, N373I, N373W, H374E, H374F, H374D, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, A377I, H378A, H378T, H378I, H378R, H378C, H378M, H378N, H378G, H378L, H378V, H378S, H378Y, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, T385F, T385M, V388E, V388D, V388Y, V388K, N390R, R391C, R391M and R391 and the thermostability is improved by at least 0.5° C. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, D4L, D4C, V5H, N8Q, V9H, S10H, A11P, A11I, A11N, A11G, A11Y, A11C, E12G, E12R, E12K, K13Q, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, G18H, G18Y, G18W, G18F, L31Q, L31H, L31P, L31G, L31S, A34F, G43W, N45D, N45W, N45S, N45F, Q46D, Q46H, G48L, G48V, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, N59C, N59V, N61W, N61L, N61E, N61H, N62A, N62V, N62L, N62C, V67A, V67S, I79K, P88M, P88F, T94H, T101L, T101R, S102R, K104R, A113E, A113Q, D120R, D120A, D120S, N128H, Y143H, Y143R, H145Y, E146R, E146H, E146Y, E146F, M159C, S165Y, S165M, F176H, F176R, F176Y, F176K, L179D, L179N, L179C, L179A, L179R, L179K, L179S, N181C, N188M, A194H, N195H, M196L, D197A, D197S, D197Q, D197G, D197P, S209C, P212K, P212Q, P212R, P212E, A221R, A221K, D224Q, Y231T, Y231V, Y231S, Y231A, S235A, T237P, Y269Q, Y269M, Y269I, Y269F, Y269L, T282H, T282R, T282C, T282V, K295W, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, V302S, V302R, V302T, V302A, V302Q, V302G, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, N311R, N311M, N311I, A312I, A312R, A312M, N313D, D322F, D322G, N323A, S333I, S333R, N334I, T335I, G336C, Q339I, L343C, L343Q, Q344I, N345C, S347R, S347H, S357V, S359H, S359Q, S359F, Q363V, T366N, T366W, N367Y, L368D, S371F, S371W, S371V, N373D, N373I, H374E, H374F, W376A, W376Q, W376D, W376M, H378A, H378T, H378I, H378R, H378C, H378M, P380M, P380D, P380E, P380C, P380V, P380I, P380L, V388E, V388D and R391C and the thermostability is improved by at least 1.0° C. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q, D4L, D4C, V9H, A11P, E12G, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, G18H, G18Y, L31Q, L31H, N45D, G48L, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, N59C, N61W, N61L, I79K, P88M, P88F, T94H, T101L, T101R, S102R, K104R, Y143H, Y143R, H145Y, E146R, E146H, E146Y, E146F, M159C, S165Y, S165M, F176H, F176R, F176Y, F176K, L179D, L179N, L179C, L179A, L179R, N181C, M196L, D197A, D197S, D197Q, D197G, S209C, D224Q, Y231T, Y231V, Y231S, Y231A, S235A, Y269Q, Y269M, K295W, R298Q, R298A, R298E, R298M, R298T, P299W, P299A, P299K, P299F, P299Y, P299Q, V302S, V302R, T307I, T307N, T307R, A312I, D322F, S333I, S333R, T335I, G336C, Q344I, S357V, S359H, L368D, S371F, W376A, H378A, P380M and P380D and the thermostability is improved by at least 1.5° C. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, D4L, Q14K, Q14Y, Q14A, Q14V, Q14W, G18H, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, N61W, I79K, T94H, S102R, Y143H, Y143R, H145Y, E146R, E146H, S165Y, S165M, F176H, F176R, L179D, L179N, L179C, L179A, M196L, D197A, D197S, D197Q, D197G, D224Q, Y231T, Y231V, Y231S, Y231A, Y269Q, R298Q, P299W, P299A, P299K, P299F, V302S, T307I and S333I and the thermostability is improved by at least 2.0° C. 
     In an embodiment, the one or more substitutions are selected from the group consisting of A2D, D4L, Q14K, Q14Y, G18H, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, T94H, S102R, Y143H, H145Y, E146R, S165Y, F176H, F176R, L179D, L179N, L179C, L179A, M196L, D197A, D197S, D197Q, Y231T, Y231V, Y269Q, P299W, P299A, P299K and S333I and the thermostability is improved by at least 2.5° C. 
     In one embodiment to any part of the fourth aspect, the liquid formulation comprises one or more polyols, preferably a polyol selected from the group consisting of glycerol, sorbitol, propylene glycol (MPG), ethylene glycol, diethylene glycol, triethylene glycol, 1, 2-propylene glycol or 1, 3-propylene glycol, dipropylene glycol, polyethylene glycol (PEG) having an average molecular weight below about 600 and polypropylene glycol (PPG) having an average molecular weight below about 600, more preferably selected from the group consisting of glycerol, sorbitol and propylene glycol (MPG) or any combination thereof. 
     In one embodiment to any part of the fourth aspect, the liquid formulation comprises 20%-80% polyol (i.e. total amount of polyol), preferably 25%-75% polyol, more preferably 30%-70% polyol, more preferably 35%-65% polyol or most preferably 40%-60% polyol. In one embodiment to any part of the fourth aspect, the liquid formulation comprises 20%-80% polyol, preferably 25%-75% polyol, more preferably 30%-70% polyol, more preferably 35%-65% polyol or most preferably 40%-60% polyol wherein the polyol is selected from the group consisting of glycerol, sorbitol, propylene glycol (MPG), ethylene glycol, diethylene glycol, triethylene glycol, 1, 2-propylene glycol or 1, 3-propylene glycol, dipropylene glycol, polyethylene glycol (PEG) having an average molecular weight below about 600 and polypropylene glycol (PPG) having an average molecular weight below about 600. In one embodiment to any part of the fourth aspect, the liquid formulation comprises 20%-80% polyol (i.e. total amount of polyol), preferably 25%-75% polyol, more preferably 30%-70% polyol, more preferably 35%-65% polyol or most preferably 40%-60% polyol wherein the polyol is selected from the group consisting of glycerol, sorbitol and propylene glycol (MPG). 
     In one embodiment to any part of the fourth aspect, the preservative is selected from the group consisting of sodium sorbate, potassium sorbate, sodium benzoate and potassium benzoate or any combination thereof. In one embodiment, the liquid formulation comprises 0.02% to 1.5% w/w preservative, more preferably 0.05% to 1.0% w/w preservative or most preferably 0.1% to 0.5% w/w preservative. In one embodiment, the liquid formulation comprises 0.001% to 2.0% w/w preservative (i.e. total amount of preservative), preferably 0.02% to 1.5% w/w preservative, more preferably 0.05% to 1.0% w/w preservative or most preferably 0.1% to 0.5% w/w preservative wherein the preservative is selected from the group consisting of sodium sorbate, potassium sorbate, sodium benzoate and potassium benzoate or any combination thereof. 
     In one embodiment to any part of the fourth aspect, the liquid formulation comprises 0.01% to 25% w/w xylanase variant, preferably 0.05% to 20% w/w, more preferably 0.2% to 15% w/w, more preferably 0.5% to 15% w/w or most preferably 1.0% to 10% w/w xylanase variant. 
     In one embodiment to any part of the fourth aspect, the liquid formulation comprises one or more formulating agents (such as those described herein), preferably a formulating agent selected from the list consisting of glycerol, ethylene glycol, 1, 2-propylene glycol or 1, 3-propylene glycol, sodium chloride, sodium benzoate, potassium sorbate, sodium sulfate, potassium sulfate, magnesium sulfate, sodium thiosulfate, calcium carbonate, sodium citrate, dextrin, glucose, sucrose, sorbitol, lactose, starch, PVA, acetate and phosphate, preferably selected from the list consisting of 1, 2-propylene glycol, 1, 3-propylene glycol, sodium sulfate, dextrin, cellulose, sodium thiosulfate, kaolin and calcium carbonate. 
     In one embodiment to any part of the fourth aspect, the liquid formulation comprises one or more additional enzymes. The one or more additional enzymes is preferably selected from the group consisting of acetylxylan esterase, acylglycerol lipase, amylase, alpha-amylase, beta-amylase, arabinofuranosidase, cellobiohydrolases, cellulase, feruloyl esterase, galactanase, alpha-galactosidase, beta-galactosidase, beta-glucanase, beta-glucosidase, lysophospholipase, lysozyme, alpha-mannosidase, beta-mannosidase (mannanase), phytase, phospholipase A1, phospholipase A2, phospholipase D, protease, pullulanase, pectinesterase, triacylglycerol lipase, xylanase, beta-xylosidase or any combination thereof. 
     In one embodiment to any part of the fourth aspect, the liquid formulation comprises one or more probiotics. The one or more probiotics is preferably selected from the group consisting of  Bacillus subtilis, Bacillus licheniformis, Bacillus amyloliquefaciens, Bacillus cereus, Bacillus pumilus, Bacillus polymyxa, Bacillus megaterium, Bacillus coagulans, Bacillus circulans, Bifidobacterium bifidum, Bifidobacterium animalis, Bifidobacterium  sp.,  Carnobacterium  sp.,  Clostridium butyricum, Clostridium  sp.,  Enterococcus faecium, Enterococcus  sp.,  Lactobacillus  sp.,  Lactobacillus acidophilus, Lactobacillus farciminus, Lactobacillus rhamnosus, Lactobacillus reuteri, Lactobacillus salivarius, Lactococcus lactis, Lactococcus  sp.,  Leuconostoc  sp.,  Megasphaera elsdenii, Megasphaera  sp.,  Pediococcus acidilactici, Pediococcus  sp.,  Propionibacterium thoenii, Propionibacterium  sp. and  Streptococcus  sp. or any combination thereof. 
     Parent Xylanases 
     In one embodiment, the parent xylanase is obtained or obtainable from the taxonomic order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus  Bacillus  or  Paenibacillus , or even more preferably from the taxonomic species  Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis  or  Paenibacillus pabuli . In one embodiment, the parent xylanase has at least 70%, e.g., at at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 1 and is obtained or obtainable from the taxonomic order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus  Bacillus  or  Paenibacillus , or even more preferably from the taxonomic species  Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis  or  Paenibacillus pabuli . In one embodiment, the xylanase is a GH30 subfamily 8 xylanase (herein referred to as GH30_8 xylanases). 
     The parent xylanase may be (a) a polypeptide having at least 70% sequence identity to SEQ ID NO: 1, e.g., at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, which have xylanase activity. In one aspect, the amino acid sequence of the parent differs by up to 10 amino acids, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, from SEQ ID NO: 1. In one embodiment, the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 1, is a fragment of SEQ ID NO: 1 wherein the fragment has xylanase activity or comprises the amino acid sequence of SEQ ID NO: 1 and an N- and/or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids. 
     The parent xylanase may be (a) a polypeptide having at least 70% sequence identity to SEQ ID NO: 2, e.g., at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, which have xylanase activity. In one aspect, the amino acid sequence of the parent differs by up to 10 amino acids, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, from SEQ ID NO: 2. In one embodiment, the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 2, is a fragment of SEQ ID NO: 2 wherein the fragment has xylanase activity or comprises the amino acid sequence of SEQ ID NO: 2 and an N- and/or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids. 
     The parent xylanase may be (a) a polypeptide having at least 70% sequence identity to SEQ ID NO: 3, e.g., at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, which have xylanase activity. In one aspect, the amino acid sequence of the parent differs by up to 10 amino acids, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, from SEQ ID NO: 3. In one embodiment, the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 3, is a fragment of SEQ ID NO: 3 wherein the fragment has xylanase activity or comprises the amino acid sequence of SEQ ID NO: 3 and an N- and/or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids. 
     The parent xylanase may be (a) a polypeptide having at least 70% sequence identity to SEQ ID NO: 4, e.g., at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, which have xylanase activity. In one aspect, the amino acid sequence of the parent differs by up to 10 amino acids, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, from SEQ ID NO: 4. In one embodiment, the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 4, is a fragment of SEQ ID NO: 4 wherein the fragment has xylanase activity or comprises the amino acid sequence of SEQ ID NO: 4 and an N- and/or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids. 
     The parent xylanase may be (a) a polypeptide having at least 70% sequence identity to SEQ ID NO: 5, e.g., at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, which have xylanase activity. In one aspect, the amino acid sequence of the parent differs by up to 10 amino acids, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, from SEQ ID NO: 5. In one embodiment, the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 5, is a fragment of SEQ ID NO: 5 wherein the fragment has xylanase activity or comprises the amino acid sequence of SEQ ID NO: 5 and an N- and/or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids. 
     The parent xylanase may be (a) a polypeptide having at least 70% sequence identity to SEQ ID NO: 6, e.g., at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, which have xylanase activity. In one aspect, the amino acid sequence of the parent differs by up to 10 amino acids, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, from SEQ ID NO: 6. In one embodiment, the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 6, is a fragment of SEQ ID NO: 6 wherein the fragment has xylanase activity or comprises the amino acid sequence of SEQ ID NO: 6 and an N- and/or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids. 
     Other examples of parent xylanases are the following GENESEQP accession numbers: BCM03690, BBY25441, BBD43833, AZG87760, BBW75090, BCM03682, BBW96675, BCM03671, ADJ35022, BBW83525, BCM03685, BBW88031, BCM03707, AZH70238, AZG87766, BBX36748, BCM03686, AZQ23477, BCM03677, BCM03691, BCM03681, BCM03676, BCM03688, AZG68558, ADJ35028, BCM03687, BBG80964, AZX66647, AZH70244, BCM03689, AZM95903, BBW79314, BBX47049, BCM03683, BCM03679, BBW95840, BBX52401, BBW92246, BBX42063 and AZG68552. 
     Other examples of parent xylanases are following Uniprot accession numbers: A0A016QIT0, A0A024BEN2, A0A059N8P2, A0A060J1Q4, A0A060J3N3, A0A060MDP8, A0A063XEB2, A0A063Z3F5, A0A066ZQH2, A0A068QG80, A0A069DJA1, A0A074QA16, A0A076GH62, A0A076X095, A0A080UGI0, A0A081 DRH7, A0A081 L9P3, A0A085CCQ4, A0A086DRT4, A0A086SGC4, A0A086WWT9, A0A089J0T9, A0A089L7Q4, A0A089LS30, A0A089MA96, A0A089MMY5, A0A090ZY18, A0A093UG96, A0A097RET6, A0A097RT57, A0A0A0TJX0, A0A0A0TS05, A0A0A1STB1, A0A0A7GLZ8, A0A0A8C3V5, A0A0B0QGI0, A0A0B4S841, A0A0C2TMZ1, A0A0C5CYD2, A0A0D7XHL0, A0A0D7XPV8, A0A0D8JJW7, A0A0E1LNG3, A0A0E1P2T5, A0A0F5MCQ0, A0A0F5YUV2, A0A0G2M1V3, A0A0G2Z099, A0A0G3VDP8, A0A0H1RW51, A0A0H3DZC9, A0A0J1HNE5, A0A0J1I8S6, A0A0J5XBB3, A0A0J6E3H1, A0A0J6ENY2, A0A0J6MZ81, A0A0J6PTT5, A0A0K0HYL4, A0A0K6JZ62, A0A0K6L1E5, A0A0K6L5C0, A0A0K6LRC5, A0A0K6MBZ9, A0A0K9EI79, A0A0K9G2M8, A0A0L6C9N3, A0A0L7MT05, A0A0L7SGL4, A0A0M0HBT0, A0A0M2EI36, A0A0M2S6E2, A0A0M9X369, A0A0P0TKN9, A0A0P7GC51, A0A0Q3W7T1, A0A0Q4R8I7, A0A0Q7SDS0, A0A0R3K873, A0A0T6LD54, A0A0U3M226, A0A0U5Q000, A0A0V8QN06, A0A0V8QPQ0, A0A0V8RCK0, A0A0W1Q0Y8, A0A0W7XI48, A0A0W8K830, A0A0X1TCR2, A0A0X8C7K8, A0A0X8DHN5, A0A0X8KDH2, A0A101YC92, A0A101YL97, A0A117SZP6, A0A124JQM2, A0A125UIF6, A0A127DQZ4, A0A132BP80, A0A132TGU4, A0A132TSQ5, A0A136AEB9, A0A142F586, A0A150L2Y6, A0A160EHD0, A0A164XMN2, A0A172HNW1, A0A172XIR5, A0A199NI63, A0A199WHT5, A0A1A0CC44, A0A1A0G7Q3, A0A1A5VV23, A0A1A5YLD9, A0A1A7LKF3, A0A1B2AW76, A0A1C3SIT4, A0A1C4AHG6, A0A1D9PK78, A0A1E4Y0F1, A0A1G9MAD1, A0A1J0BBP6, A0A1J0C7I7, A0A1J5WRC5, A0A1J6F1D5, A0A1K1TBA7, A0A1L3PT45, A0A1L3QYI6, A0A1L3SH52, A0A1L4DM20, A0A1L5LNU4, A0A1L6CEM3, A0A1L6ZLN8, A0A1L6ZTD9, A0A1M7SMM4, A0A1N6S500, A0A1N7B930, A0A1N7E7E0, A0A1R1E8G3, A0A1R1ESJ7, A0A1R1FQ77, A0A1R1GBK8, A0A1R1GT02, A0A1R1HH77, A0A1S2F2R2, A0A1U3ULV5, A7Z5A1, A8FDV2, B3KF38, D1MEP8, D3EH02, D4FXC2, E0RDU2, E1ACF9, E1UV03, E3E322, E8VJ45, F4E4B0, F4EKU6, G0IKW9, G4EVQ6, G4HGL4, G4P7F1, G7W2J1, H0FNN1, H1ACZ7, H2AJ54, H3K352, H6CPJ0, H6WCZ0, H8XMR3, I4XB64, J0X3V6, J7JVZ4, K2HJT3, K2P3H7, L0BLZ3, L0CY72, L8AKB2, M1KJT1, M1U2J5, M1XAU4, M2U9N8, N0DFI8, Q45070, Q6YK37, Q70K02, R9TYN3, S6FS40, S6FXS9, U1T362, U1ZC44, U2TM90, U4PL99, U5X5B8, V5MRU9, V7Q6M1, V9REY3, W4AZH7, W4BXI4, W4C6X9, W4D801, W4DEL3, W8ILG7 and W9TFT6. 
     The polypeptide may be a hybrid polypeptide in which a region of one polypeptide is fused at the N-terminus or the C-terminus of a region of another polypeptide. 
     The parent may be a fusion polypeptide or cleavable fusion polypeptide in which another polypeptide is fused at the N-terminus or the C-terminus of the polypeptide of the present invention. A fusion polypeptide is produced by fusing a polynucleotide encoding another polypeptide to a polynucleotide of the present invention. Techniques for producing fusion polypeptides are known in the art, and include ligating the coding sequences encoding the polypeptides so that they are in frame and that expression of the fusion polypeptide is under control of the same promoter(s) and terminator. Fusion polypeptides may also be constructed using intein technology in which fusion polypeptides are created post-translationally (Cooper et al., 1993 , EMBO J.  12: 2575-2583; Dawson et al., 1994 , Science  266: 776-779). 
     A fusion polypeptide can further comprise a cleavage site between the two polypeptides. Upon secretion of the fusion protein, the site is cleaved releasing the two polypeptides. Examples of cleavage sites include, but are not limited to, the sites disclosed in Martin et al., 2003 , J. Ind. Microbiol. Biotechnol.  3: 568-576; Svetina et al., 2000 , J. Biotechnol.  76: 245-251; Rasmussen-Wilson et al., 1997 , Appl. Environ. Microbiol.  63: 3488-3493; Ward et al., 1995 , Biotechnology  13: 498-503; and Contreras et al., 1991 , Biotechnology  9: 378-381; Eaton et al., 1986 , Biochemistry  25: 505-512; Collins-Racie et al., 1995 , Biotechnology  13: 982-987; Carter et al., 1989 , Proteins: Structure, Function, and Genetics  6: 240-248; and Stevens, 2003 , Drug Discovery World  4: 35-48. 
     The parent may be obtained from microorganisms of any genus. For purposes of the present invention, the term “obtained from” as used herein in connection with a given source shall mean that the parent encoded by a polynucleotide is produced by the source or by a strain in which the polynucleotide from the source has been inserted. In one aspect, the parent is secreted extracellularly. 
     The polypeptide may be a bacterial polypeptide. For example, the polypeptide may be a Gram-positive bacterial polypeptide such as a  Bacillus, Clostridium, Enterococcus, Geobacillus, Lactobacillus, Lactococcus, Oceanobacillus, Staphylococcus, Streptococcus , or  Streptomyces  polypeptide having xylanase activity. In one embodiment, the polypeptide is from a bacterium of the class Bacilli, such as from the order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus  Bacillus  or  Paenibacillus , or even more preferably from the taxonomic species  Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis  or  Paenibacillus pabuli.    
     In one aspect, the parent is a  Bacillus alkalophilus, Bacillus amyloliquefaciens, Bacillus brevis, Bacillus circulans, Bacillus clausii, Bacillus coagulans, Bacillus firmus, Bacillus lautus, Bacillus lentus, Bacillus licheniformis, Bacillus megaterium, Bacillus pumilus, Bacillus stearothermophilus, Bacillus subtilis , or  Bacillus thuringiensis  xylanase. 
     In a preferred aspect, the parent is a  Bacillus subtilis  xylanase, e.g., the xylanase having the amino acid sequence of SEQ ID NO: 1. 
     It will be understood that for the aforementioned species, the invention encompasses both the perfect and imperfect states, and other taxonomic equivalents, e.g., anamorphs, regardless of the species name by which they are known. Those skilled in the art will readily recognize the identity of appropriate equivalents. 
     Strains of these species are readily accessible to the public in a number of culture collections, such as the American Type Culture Collection (ATCC), Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH (DSMZ), Centraalbureau Voor Schimmelcultures (CBS), and Agricultural Research Service Patent Culture Collection, Northern Regional Research Center (NRRL). 
     The parent may be identified and obtained from other sources including microorganisms isolated from nature (e.g., soil, composts, water, etc.) or DNA samples obtained directly from natural materials (e.g., soil, composts, water, etc.) using the above-mentioned probes. Techniques for isolating microorganisms and DNA directly from natural habitats are well known in the art. A polynucleotide encoding a parent may then be obtained by similarly screening a genomic DNA or cDNA library of another microorganism or mixed DNA sample. Once a polynucleotide encoding a parent has been detected with the probe(s), the polynucleotide can be isolated or cloned by utilizing techniques that are known to those of ordinary skill in the art (see, e.g., Sambrook et al., 1989, supra). 
     Polynucleotides 
     The present invention also relates to isolated polynucleotides encoding a variant of the present invention. 
     Nucleic Acid Constructs 
     The present invention also relates to nucleic acid constructs comprising a polynucleotide encoding a variant of the present invention operably linked to one or more control sequences that direct the expression of the coding sequence in a suitable host cell under conditions compatible with the control sequences. 
     The polynucleotide may be manipulated in a variety of ways to provide for expression of a variant. Manipulation of the polynucleotide prior to its insertion into a vector may be desirable or necessary depending on the expression vector. The techniques for modifying polynucleotides utilizing recombinant DNA methods are well known in the art. 
     The control sequence may be a promoter, a polynucleotide which is recognized by a host cell for expression of the polynucleotide. The promoter contains transcriptional control sequences that mediate the expression of the variant. The promoter may be any polynucleotide that shows transcriptional activity in the host cell including mutant, truncated, and hybrid promoters, and may be obtained from genes encoding extracellular or intracellular polypeptides either homologous or heterologous to the host cell. 
     Examples of suitable promoters for directing transcription of the nucleic acid constructs of the present invention in a bacterial host cell are the promoters obtained from the  Bacillus amyloliquefaciens  alpha-amylase gene (amyQ),  Bacillus licheniformis  alpha-amylase gene (amyL),  Bacillus licheniformis  penicillinase gene (penP),  Bacillus stearothermophilus  maltogenic amylase gene (amyM),  Bacillus subtilis  levansucrase gene (sacB),  Bacillus subtilis  xylA and xylB genes,  Bacillus thuringiensis  cryIIIA gene (Agaisse and Lereclus, 1994 , Molecular Microbiology  13: 97-107),  E. coli  lac operon,  E. coli  trc promoter (Egon et al., 1988 , Gene  69: 301-315),  Streptomyces coelicolor  agarase gene (dagA), and prokaryotic beta-lactamase gene (Villa-Kamaroff et al., 1978 , Proc. Natl. Acad. Sci. USA  75: 3727-3731), as well as the tac promoter (DeBoer et al., 1983 , Proc. Natl. Acad. Sci. USA  80: 21-25). Further promoters are described in “Useful proteins from recombinant bacteria” in Gilbert et al., 1980 , Scientific American  242: 74-94; and in Sambrook et al., 1989, supra. Examples of tandem promoters are disclosed in WO 99/43835. 
     Examples of suitable promoters for directing transcription of the nucleic acid constructs of the present invention in a filamentous fungal host cell are promoters obtained from the genes for  Aspergillus nidulans  acetamidase,  Aspergillus niger  neutral alpha-amylase,  Aspergillus niger  acid stable alpha-amylase,  Aspergillus niger  or  Aspergillus awamori  glucoamylase (glaA),  Aspergillus oryzae  TAKA amylase,  Aspergillus oryzae  alkaline protease,  Aspergillus oryzae  triose phosphate isomerase,  Fusarium oxysporum  trypsin-like protease (WO 96/00787),  Fusarium venenatum  amyloglucosidase (WO 00/56900),  Fusarium venenatum  Daria (WO 00/56900),  Fusarium venenatum  Quinn (WO 00/56900),  Rhizomucor miehei  lipase,  Rhizomucor miehei  aspartic proteinase,  Trichoderma reesei  beta-glucosidase,  Trichoderma reesei  cellobiohydrolase I,  Trichoderma reesei  cellobiohydrolase II,  Trichoderma reesei  endoglucanase I,  Trichoderma reesei  endoglucanase II,  Trichoderma reesei  endoglucanase III,  Trichoderma reesei  endoglucanase IV,  Trichoderma reesei  endoglucanase V,  Trichoderma reesei  xylanase I,  Trichoderma reesei  xylanase II,  Trichoderma reesei  beta-xylosidase, as well as the NA2-tpi promoter (a modified promoter from an  Aspergillus  neutral alpha-amylase gene in which the untranslated leader has been replaced by an untranslated leader from an  Aspergillus  triose phosphate isomerase gene; non-limiting examples include modified promoters from an  Aspergillus niger  neutral alpha-amylase gene in which the untranslated leader has been replaced by an untranslated leader from an  Aspergillus nidulans  or  Aspergillus oryzae  triose phosphate isomerase gene); and mutant, truncated, and hybrid promoters thereof. 
     In a yeast host, useful promoters are obtained from the genes for  Saccharomyces cerevisiae  enolase (ENO-1),  Saccharomyces cerevisiae  galactokinase (GAL1),  Saccharomyces cerevisiae  alcohol dehydrogenase/glyceraldehyde-3-phosphate dehydrogenase (ADH1, ADH2/GAP),  Saccharomyces cerevisiae  triose phosphate isomerase (TPI),  Saccharomyces cerevisiae  metallothionein (CUP1), and  Saccharomyces cerevisiae  3-phosphoglycerate kinase. Other useful promoters for yeast host cells are described by Romanos et al., 1992 , Yeast  8: 423-488. 
     The control sequence may also be a transcription terminator, which is recognized by a host cell to terminate transcription. The terminator sequence is operably linked to the 3′-terminus of the polynucleotide encoding the variant. Any terminator that is functional in the host cell may be used. 
     Preferred terminators for bacterial host cells are obtained from the genes for  Bacillus clausii  alkaline protease (aprH),  Bacillus licheniformis  alpha-amylase (amyL), and  Escherichia coli  ribosomal RNA (rrnB). 
     Preferred terminators for filamentous fungal host cells are obtained from the genes for  Aspergillus nidulans  anthranilate synthase,  Aspergillus niger  glucoamylase,  Aspergillus niger  alpha-glucosidase,  Aspergillus oryzae  TAKA amylase, and  Fusarium oxysporum  trypsin-like protease. 
     Preferred terminators for yeast host cells are obtained from the genes for  Saccharomyces cerevisiae  enolase,  Saccharomyces cerevisiae  cytochrome C (CYC1), and  Saccharomyces cerevisiae  glyceraldehyde-3-phosphate dehydrogenase. Other useful terminators for yeast host cells are described by Romanos et al., 1992, supra. 
     The control sequence may also be an mRNA stabilizer region downstream of a promoter and upstream of the coding sequence of a gene which increases expression of the gene. 
     Examples of suitable mRNA stabilizer regions are obtained from a  Bacillus thuringiensis  cryIIIA gene (WO 94/25612) and a  Bacillus subtilis  SP82 gene (Hue et al., 1995 , Journal of Bacteriology  177: 3465-3471). 
     The control sequence may also be a leader, a nontranslated region of an mRNA that is important for translation by the host cell. The leader sequence is operably linked to the 5′-terminus of the polynucleotide encoding the variant. Any leader that is functional in the host cell may be used. 
     Preferred leaders for filamentous fungal host cells are obtained from the genes for  Aspergillus oryzae  TAKA amylase and  Aspergillus nidulans  triose phosphate isomerase. 
     Suitable leaders for yeast host cells are obtained from the genes for  Saccharomyces cerevisiae  enolase (ENO-1),  Saccharomyces cerevisiae  3-phosphoglycerate kinase,  Saccharomyces cerevisiae  alpha-factor, and  Saccharomyces cerevisiae  alcohol dehydrogenase/glyceraldehyde-3-phosphate dehydrogenase (ADH2/GAP). 
     The control sequence may also be a polyadenylation sequence, a sequence operably linked to the 3′-terminus of the variant-encoding sequence and, when transcribed, is recognized by the host cell as a signal to add polyadenosine residues to transcribed mRNA. Any polyadenylation sequence that is functional in the host cell may be used. 
     Preferred polyadenylation sequences for filamentous fungal host cells are obtained from the genes for  Aspergillus nidulans  anthranilate synthase,  Aspergillus niger  glucoamylase,  Aspergillus niger  alpha-glucosidase,  Aspergillus oryzae  TAKA amylase, and  Fusarium oxysporum  trypsin-like protease. 
     Useful polyadenylation sequences for yeast host cells are described by Guo and Sherman, 1995 , Mol. Cellular Biol.  15: 5983-5990. 
     The control sequence may also be a signal peptide coding region that encodes a signal peptide linked to the N-terminus of a variant and directs the variant into the cell&#39;s secretory pathway. The 5′-end of the coding sequence of the polynucleotide may inherently contain a signal peptide coding sequence naturally linked in translation reading frame with the segment of the coding sequence that encodes the variant. Alternatively, the 5′-end of the coding sequence may contain a signal peptide coding sequence that is foreign to the coding sequence. A foreign signal peptide coding sequence may be required where the coding sequence does not naturally contain a signal peptide coding sequence. Alternatively, a foreign signal peptide coding sequence may simply replace the natural signal peptide coding sequence in order to enhance secretion of the variant. However, any signal peptide coding sequence that directs the expressed variant into the secretory pathway of a host cell may be used. 
     Effective signal peptide coding sequences for bacterial host cells are the signal peptide coding sequences obtained from the genes for  Bacillus  NCIB 11837 maltogenic amylase,  Bacillus licheniformis  subtilisin,  Bacillus licheniformis  beta-lactamase,  Bacillus stearothermophilus  alpha-amylase,  Bacillus stearothermophilus  neutral proteases (nprT, nprS, nprM), and  Bacillus subtilis  prsA. Further signal peptides are described by Simonen and Palva, 1993 , Microbiological Reviews  57: 109-137. 
     Effective signal peptide coding sequences for filamentous fungal host cells are the signal peptide coding sequences obtained from the genes for  Aspergillus niger  neutral amylase,  Aspergillus niger  glucoamylase,  Aspergillus oryzae  TAKA amylase,  Humicola insolens  cellulase,  Humicola insolens  endoglucanase V,  Humicola lanuginosa  lipase, and  Rhizomucor miehei  aspartic proteinase. 
     Useful signal peptides for yeast host cells are obtained from the genes for  Saccharomyces cerevisiae  alpha-factor and  Saccharomyces cerevisiae  invertase. Other useful signal peptide coding sequences are described by Romanos et al., 1992, supra. 
     The control sequence may also be a propeptide coding sequence that encodes a propeptide positioned at the N-terminus of a variant. The resultant polypeptide is known as a proenzyme or propolypeptide (or a zymogen in some cases). A propolypeptide is generally inactive and can be converted to an active polypeptide by catalytic or autocatalytic cleavage of the propeptide from the propolypeptide. The propeptide coding sequence may be obtained from the genes for  Bacillus subtilis  alkaline protease (aprE),  Bacillus subtilis  neutral protease (nprT),  Myceliophthora thermophila  laccase (WO 95/33836),  Rhizomucor miehei  aspartic proteinase, and  Saccharomyces cerevisiae  alpha-factor. 
     Where both signal peptide and propeptide sequences are present, the propeptide sequence is positioned next to the N-terminus of the variant and the signal peptide sequence is positioned next to the N-terminus of the propeptide sequence. 
     It may also be desirable to add regulatory sequences that regulate expression of the variant relative to the growth of the host cell. Examples of regulatory systems are those that cause expression of the gene to be turned on or off in response to a chemical or physical stimulus, including the presence of a regulatory compound. Regulatory systems in prokaryotic systems include the lac, tac, and trp operator systems. In yeast, the ADH2 system or GAL1 system may be used. In filamentous fungi, the  Aspergillus niger  glucoamylase promoter,  Aspergillus oryzae  TAKA alpha-amylase promoter, and  Aspergillus oryzae  glucoamylase promoter may be used. Other examples of regulatory sequences are those that allow for gene amplification. In eukaryotic systems, these regulatory sequences include the dihydrofolate reductase gene that is amplified in the presence of methotrexate, and the metallothionein genes that are amplified with heavy metals. In these cases, the polynucleotide encoding the variant would be operably linked with the regulatory sequence. 
     Expression Vectors 
     The present invention also relates to recombinant expression vectors comprising a polynucleotide encoding a variant of the present invention, a promoter, and transcriptional and translational stop signals. The various nucleotide and control sequences may be joined together to produce a recombinant expression vector that may include one or more convenient restriction sites to allow for insertion or substitution of the polynucleotide encoding the variant at such sites. Alternatively, the polynucleotide may be expressed by inserting the polynucleotide or a nucleic acid construct comprising the polynucleotide into an appropriate vector for expression. In creating the expression vector, the coding sequence is located in the vector so that the coding sequence is operably linked with the appropriate control sequences for expression. 
     The recombinant expression vector may be any vector (e.g., a plasmid or virus) that can be conveniently subjected to recombinant DNA procedures and can bring about expression of the polynucleotide. The choice of the vector will typically depend on the compatibility of the vector with the host cell into which the vector is to be introduced. The vector may be a linear or closed circular plasmid. 
     The vector may be an autonomously replicating vector, i.e., a vector that exists as an extrachromosomal entity, the replication of which is independent of chromosomal replication, e.g., a plasmid, an extrachromosomal element, a minichromosome, or an artificial chromosome. The vector may contain any means for assuring self-replication. Alternatively, the vector may be one that, when introduced into the host cell, is integrated into the genome and replicated together with the chromosome(s) into which it has been integrated. Furthermore, a single vector or plasmid or two or more vectors or plasmids that together contain the total DNA to be introduced into the genome of the host cell, or a transposon, may be used. 
     The vector may contain one or more selectable markers that permit easy selection of transformed, transfected, transduced, or the like cells. A selectable marker is a gene the product of which provides for biocide or viral resistance, resistance to heavy metals, prototrophy to auxotrophs, and the like. 
     Examples of bacterial selectable markers are  Bacillus licheniformis  or  Bacillus subtilis  dal genes, or markers that confer antibiotic resistance such as ampicillin, chloramphenicol, kanamycin, neomycin, spectinomycin or tetracycline resistance. Suitable markers for yeast host cells include, but are not limited to, ADE2, HIS3, LEU2, LYS2, MET3, TRP1, and URA3. Selectable markers for use in a filamentous fungal host cell include, but are not limited to, amdS (acetamidase), argB (ornithine carbamoyltransferase), bar (phosphinothricin acetyltransferase), hph (hygromycin phosphotransferase), niaD (nitrate reductase), pyrG (orotidine-5′-phosphate decarboxylase), sC (sulfate adenyltransferase), and trpC (anthranilate synthase), as well as equivalents thereof. Preferred for use in an  Aspergillus  cell are  Aspergillus nidulans  or  Aspergillus oryzae  amdS and pyrG genes and a  Streptomyces hygroscopicus  bar gene. 
     The vector may contain an element(s) that permits integration of the vector into the host cell&#39;s genome or autonomous replication of the vector in the cell independent of the genome. 
     For integration into the host cell genome, the vector may rely on the polynucleotide&#39;s sequence encoding the variant or any other element of the vector for integration into the genome by homologous or non-homologous recombination. Alternatively, the vector may contain additional polynucleotides for directing integration by homologous recombination into the genome of the host cell at a precise location(s) in the chromosome(s). To increase the likelihood of integration at a precise location, the integrational elements should contain a sufficient number of nucleic acids, such as 100 to 10,000 base pairs, 400 to 10,000 base pairs, and 800 to 10,000 base pairs, which have a high degree of sequence identity to the corresponding target sequence to enhance the probability of homologous recombination. The integrational elements may be any sequence that is homologous with the target sequence in the genome of the host cell. Furthermore, the integrational elements may be non-encoding or encoding polynucleotides. On the other hand, the vector may be integrated into the genome of the host cell by non-homologous recombination. 
     For autonomous replication, the vector may further comprise an origin of replication enabling the vector to replicate autonomously in the host cell in question. The origin of replication may be any plasmid replicator mediating autonomous replication that functions in a cell. The term “origin of replication” or “plasmid replicator” means a polynucleotide that enables a plasmid or vector to replicate in vivo. 
     Examples of bacterial origins of replication are the origins of replication of plasmids pBR322, pUC19, pACYC177, and pACYC184 permitting replication in  E. coli , and pUB110, pE194, pTA1060, and pAMß1 permitting replication in  Bacillus.    
     Examples of origins of replication for use in a yeast host cell are the 2 micron origin of replication, ARS1, ARS4, the combination of ARS1 and CEN3, and the combination of ARS4 and CEN6. 
     Examples of origins of replication useful in a filamentous fungal cell are AMA1 and ANS1 (Gems et al., 1991 , Gene  98: 61-67; Cullen et al., 1987 , Nucleic Acids Res.  15: 9163-9175; WO 00/24883). Isolation of the AMA1 gene and construction of plasmids or vectors comprising the gene can be accomplished according to the methods disclosed in WO 00/24883. 
     More than one copy of a polynucleotide of the present invention may be inserted into a host cell to increase production of a variant. An increase in the copy number of the polynucleotide can be obtained by integrating at least one additional copy of the sequence into the host cell genome or by including an amplifiable selectable marker gene with the polynucleotide where cells containing amplified copies of the selectable marker gene, and thereby additional copies of the polynucleotide, can be selected for by cultivating the cells in the presence of the appropriate selectable agent. 
     The procedures used to ligate the elements described above to construct the recombinant expression vectors of the present invention are well known to one skilled in the art (see, e.g., Sambrook et al., 1989, supra). 
     Host Cells 
     The present invention also relates to recombinant host cells, comprising a polynucleotide encoding a variant of the present invention operably linked to one or more control sequences that direct the production of a variant of the present invention. A construct or vector comprising a polynucleotide is introduced into a host cell so that the construct or vector is maintained as a chromosomal integrant or as a self-replicating extra-chromosomal vector as described earlier. The term “host cell” encompasses any progeny of a parent cell that is not identical to the parent cell due to mutations that occur during replication. The choice of a host cell will to a large extent depend upon the gene encoding the variant and its source. 
     The host cell may be any cell useful in the recombinant production of a variant, e.g., a prokaryote or a eukaryote. 
     The prokaryotic host cell may be any Gram-positive or Gram-negative bacterium. Gram-positive bacteria include, but are not limited to,  Bacillus, Clostridium, Enterococcus, Geobacillus, Lactobacillus, Lactococcus, Oceanobacillus, Staphylococcus, Streptococcus , and  Streptomyces.  Gram-negative bacteria include, but are not limited to,  Campylobacter, E. coli, Flavobacterium, Fusobacterium, Helicobacter, Ilyobacter, Neisseria, Pseudomonas, Salmonella , and  Ureaplasma.    
     The bacterial host cell may be any  Bacillus  cell including, but not limited to,  Bacillus alkalophilus, Bacillus amyloliquefaciens, Bacillus brevis, Bacillus circulans, Bacillus clausii, Bacillus coagulans, Bacillus firmus, Bacillus lautus, Bacillus lentus, Bacillus licheniformis, Bacillus megaterium, Bacillus pumilus, Bacillus stearothermophilus, Bacillus subtilis , and  Bacillus thuringiensis  cells. 
     The bacterial host cell may also be any  Streptococcus  cell including, but not limited to,  Streptococcus equisimilis, Streptococcus pyogenes, Streptococcus uberis , and  Streptococcus equi  subsp.  Zooepidemicus  cells. 
     The bacterial host cell may also be any  Streptomyces  cell, including, but not limited to,  Streptomyces achromogenes, Streptomyces avermitilis, Streptomyces coelicolor, Streptomyces griseus , and  Streptomyces lividans  cells. 
     The introduction of DNA into a  Bacillus  cell may be effected by protoplast transformation (see, e.g., Chang and Cohen, 1979 , Mol. Gen. Genet.  168: 111-115), competent cell transformation (see, e.g., Young and Spizizen, 1961 , J. Bacteriol.  81: 823-829, or Dubnau and Davidoff-Abelson, 1971 , J. Mol. Biol.  56: 209-221), electroporation (see, e.g., Shigekawa and Dower, 1988 , Biotechniques  6: 742-751), or conjugation (see, e.g., Koehler and Thorne, 1987 , J. Bacteriol.  169: 5271-5278). The introduction of DNA into an  E. coli  cell may be effected by protoplast transformation (see, e.g., Hanahan, 1983 , J. Mol. Biol.  166: 557-580) or electroporation (see, e.g., Dower et al., 1988 , Nucleic Acids Res.  16: 6127-6145). The introduction of DNA into a  Streptomyces  cell may be effected by protoplast transformation, electroporation (see, e.g., Gong et al., 2004 , Folia Microbiol.  (Praha) 49: 399-405), conjugation (see, e.g., Mazodier et al., 1989 , J. Bacteriol.  171: 3583-3585), or transduction (see, e.g., Burke et al., 2001 , Proc. Natl. Acad. Sci. USA  98: 6289-6294). The introduction of DNA into a  Pseudomonas  cell may be effected by electroporation (see, e.g., Choi et al., 2006 , J. Microbiol. Methods  64: 391-397), or conjugation (see, e.g., Pinedo and Smets, 2005 , Appl. Environ. Microbiol.  71: 51-57). The introduction of DNA into a  Streptococcus  cell may be effected by natural competence (see, e.g., Perry and Kuramitsu, 1981 , Infect. Immun.  32: 1295-1297), protoplast transformation (see, e.g., Catt and Jollick, 1991 , Microbios  68: 189-207), electroporation (see, e.g., Buckley et al., 1999 , Appl. Environ. Microbiol.  65: 3800-3804) or conjugation (see, e.g., Clewell, 1981 , Microbiol. Rev.  45: 409-436). However, any method known in the art for introducing DNA into a host cell can be used. 
     The host cell may also be a eukaryote, such as a mammalian, insect, plant, or fungal cell. 
     The host cell may be a fungal cell. “Fungi” as used herein includes the phyla Ascomycota, Basidiomycota, Chytridiomycota, and Zygomycota as well as the Oomycota and all mitosporic fungi (as defined by Hawksworth et al., In,  Ainsworth and Bisby&#39;s Dictionary of The Fungi,  8th edition, 1995, CAB International, University Press, Cambridge, UK). 
     The fungal host cell may be a yeast cell. “Yeast” as used herein includes ascosporogenous yeast (Endomycetales), basidiosporogenous yeast, and yeast belonging to the Fungi Imperfecti (Blastomycetes). Since the classification of yeast may change in the future, for the purposes of this invention, yeast shall be defined as described in  Biology and Activities of Yeast  (Skinner, Passmore, and Davenport, editors,  Soc. App. Bacteriol. Symposium Series  No. 9, 1980). 
     The yeast host cell may be a  Candida, Hansenula, Kluyveromyces, Pichia, Saccharomyces, Schizosaccharomyces , or  Yarrowia  cell such as a  Kluyveromyces lactis, Saccharomyces carlsbergensis, Saccharomyces cerevisiae, Saccharomyces diastaticus, Saccharomyces douglasii, Saccharomyces kluyveri, Saccharomyces norbensis, Saccharomyces oviformis , or  Yarrowia lipolytica  cell. 
     The fungal host cell may be a filamentous fungal cell. “Filamentous fungi” include all filamentous forms of the subdivision Eumycota and Oomycota (as defined by Hawksworth et al., 1995, supra). The filamentous fungi are generally characterized by a mycelial wall composed of chitin, cellulose, glucan, chitosan, mannan, and other complex polysaccharides. Vegetative growth is by hyphal elongation and carbon catabolism is obligately aerobic. In contrast, vegetative growth by yeasts such as  Saccharomyces cerevisiae  is by budding of a unicellular thallus and carbon catabolism may be fermentative. 
     The filamentous fungal host cell may be an  Acremonium, Aspergillus, Aureobasidium, Bjerkandera, Ceriporiopsis, Chrysosporium, Coprinus, Coriolus, Cryptococcus, Filibasidium, Fusarium, Humicola, Magnaporthe, Mucor, Myceliophthora, Neocallimastix, Neurospora, Paecilomyces, Penicillium, Phanerochaete, Phlebia, Piromyces, Pleurotus, Schizophyllum, Talaromyces, Thermoascus, Thielavia, Tolypocladium, Trametes , or  Trichoderma  cell. 
     For example, the filamentous fungal host cell may be an  Aspergillus awamori, Aspergillus foetidus, Aspergillus fumigatus, Aspergillus japonicus, Aspergillus nidulans, Aspergillus niger, Aspergillus oryzae, Bjerkandera adusta, Ceriporiopsis aneirina, Ceriporiopsis caregiea, Ceriporiopsis gilvescens, Ceriporiopsis pannocinta, Ceriporiopsis rivulosa, Ceriporiopsis subrufa, Ceriporiopsis subvermispora, Chrysosporium inops, Chrysosporium keratinophilum, Chrysosporium lucknowense, Chrysosporium merdarium, Chrysosporium pannicola, Chrysosporium queenslandicum, Chrysosporium tropicum, Chrysosporium zonatum, Coprinus cinereus, Coriolus hirsutus, Fusarium bactridioides, Fusarium cerealis, Fusarium crookwellense, Fusarium culmorum, Fusarium graminearum, Fusarium graminum, Fusarium heterosporum, Fusarium negundi, Fusarium oxysporum, Fusarium reticulatum, Fusarium roseum, Fusarium sambucinum, Fusarium sarcochroum, Fusarium sporotrichioides, Fusarium sulphureum, Fusarium torulosum, Fusarium trichothecioides, Fusarium venenatum, Humicola insolens, Humicola lanuginosa, Mucor miehei, Myceliophthora thermophila, Neurospora crassa, Penicillium purpurogenum, Phanerochaete chrysosporium, Phlebia radiata, Pleurotus eryngii, Thielavia terrestris, Trametes villosa, Trametes versicolor, Trichoderma harzianum, Trichoderma koningii, Trichoderma longibrachiatum, Trichoderma reesei , or  Trichoderma viride  cell. 
     Fungal cells may be transformed by a process involving protoplast formation, transformation of the protoplasts, and regeneration of the cell wall in a manner known per se. Suitable procedures for transformation of  Aspergillus  and  Trichoderma  host cells are described in EP 238023, Yelton et al., 1984 , Proc. Natl. Acad. Sci. USA  81: 1470-1474, and Christensen et al., 1988 , Bio/Technology  6: 1419-1422. Suitable methods for transforming  Fusarium  species are described by Malardier et al., 1989 , Gene  78: 147-156, and WO 96/00787. Yeast may be transformed using the procedures described by Becker and Guarente, In Abelson, J. N. and Simon, M. I., editors,  Guide to Yeast Genetics and Molecular Biology, Methods in Enzymology , Volume 194, pp 182-187, Academic Press, Inc., New York; Ito et al., 1983 , J. Bacteriol.  153: 163; and Hinnen et al., 1978 , Proc. Natl. Acad. Sci. USA  75: 1920. 
     Methods of Production 
     The present invention also relates to methods of producing a variant, comprising: (a) cultivating a host cell of the present invention under conditions suitable for expression of the variant; and (b) recovering the variant. 
     The host cells are cultivated in a nutrient medium suitable for production of the variant using methods known in the art. For example, the cell may be cultivated by shake flask cultivation, or small-scale or large-scale fermentation (including continuous, batch, fed-batch, or solid state fermentations) in laboratory or industrial fermentors performed in a suitable medium and under conditions allowing the variant to be expressed and/or isolated. The cultivation takes place in a suitable nutrient medium comprising carbon and nitrogen sources and inorganic salts, using procedures known in the art. Suitable media are available from commercial suppliers or may be prepared according to published compositions (e.g., in catalogues of the American Type Culture Collection). If the variant is secreted into the nutrient medium, the variant can be recovered directly from the medium. If the variant is not secreted, it can be recovered from cell lysates. 
     The variant may be detected using methods known in the art that are specific for the variants. These detection methods include, but are not limited to, use of specific antibodies, formation of an enzyme product, or disappearance of an enzyme substrate. For example, an enzyme assay may be used to determine the activity of the variant. 
     The variant may be recovered using methods known in the art. For example, the variant may be recovered from the nutrient medium by conventional procedures including, but not limited to, collection, centrifugation, filtration, extraction, spray-drying, evaporation, or precipitation. 
     The variant may be purified by a variety of procedures known in the art including, but not limited to, chromatography (e.g., ion exchange, affinity, hydrophobic, chromatofocusing, and size exclusion), electrophoretic procedures (e.g., preparative isoelectric focusing), differential solubility (e.g., ammonium sulfate precipitation), SDS-PAGE, or extraction (see, e.g.,  Protein Purification,  Janson and Ryden, editors, VCH Publishers, New York, 1989) to obtain substantially pure variants. 
     In an alternative aspect, the variant is not recovered, but rather a host cell of the present invention expressing the variant is used as a source of the variant. 
     Fermentation Broth Formulations or Cell Compositions 
     The present invention also relates to a fermentation broth formulation or a cell composition comprising a polypeptide of the present invention. The fermentation broth product further comprises additional ingredients used in the fermentation process, such as, for example, cells (including, the host cells containing the gene encoding the polypeptide of the present invention which are used to produce the polypeptide of interest), cell debris, biomass, fermentation media and/or fermentation products. In some embodiments, the composition is a cell-killed whole broth containing organic acid(s), killed cells and/or cell debris, and culture medium. 
     The term “fermentation broth” as used herein refers to a preparation produced by cellular fermentation that undergoes no or minimal recovery and/or purification. For example, fermentation broths are produced when microbial cultures are grown to saturation, incubated under carbon-limiting conditions to allow protein synthesis (e.g., expression of enzymes by host cells) and secretion into cell culture medium. The fermentation broth can contain unfractionated or fractionated contents of the fermentation materials derived at the end of the fermentation. Typically, the fermentation broth is unfractionated and comprises the spent culture medium and cell debris present after the microbial cells (e.g., filamentous fungal cells) are removed, e.g., by centrifugation. In some embodiments, the fermentation broth contains spent cell culture medium, extracellular enzymes, and viable and/or nonviable microbial cells. 
     In an embodiment, the fermentation broth formulation and cell compositions comprise a first organic acid component comprising at least one 1-5 carbon organic acid and/or a salt thereof and a second organic acid component comprising at least one 6 or more carbon organic acid and/or a salt thereof. In a specific embodiment, the first organic acid component is acetic acid, formic acid, propionic acid, a salt thereof, or a mixture of two or more of the foregoing and the second organic acid component is benzoic acid, cyclohexanecarboxylic acid, 4-methylvaleric acid, phenylacetic acid, a salt thereof, or a mixture of two or more of the foregoing. 
     In one aspect, the composition contains an organic acid(s), and optionally further contains killed cells and/or cell debris. In one embodiment, the killed cells and/or cell debris are removed from a cell-killed whole broth to provide a composition that is free of these components. 
     The fermentation broth formulations or cell compositions may further comprise a preservative and/or anti-microbial (e.g., bacteriostatic) agent, including, but not limited to, sorbitol, sodium chloride, potassium sorbate, and others known in the art. 
     The cell-killed whole broth or composition may contain the unfractionated contents of the fermentation materials derived at the end of the fermentation. Typically, the cell-killed whole broth or composition contains the spent culture medium and cell debris present after the microbial cells (e.g., filamentous fungal cells) are grown to saturation, incubated under carbon-limiting conditions to allow protein synthesis. In some embodiments, the cell-killed whole broth or composition contains the spent cell culture medium, extracellular enzymes, and killed filamentous fungal cells. In some embodiments, the microbial cells present in the cell-killed whole broth or composition can be permeabilized and/or lysed using methods known in the art. 
     A whole broth or cell composition as described herein is typically a liquid, but may contain insoluble components, such as killed cells, cell debris, culture media components, and/or insoluble enzyme(s). In some embodiments, insoluble components may be removed to provide a clarified liquid composition. 
     The whole broth formulations and cell compositions of the present invention may be produced by a method described in WO 90/15861 or WO 2010/096673. 
     Enzyme Compositions 
     The present invention also relates to compositions comprising a polypeptide of the present invention. Preferably, the compositions are enriched in the polypeptide of the invention. The term “enriched” indicates that the xylanase activity of the composition has been increased, e.g., with an enrichment factor of at least 1.1, such as at least 1.2, at least 1.3, at least 1.4, at least 1.5, at least 2.0, at least 3.0, at least 4.0, at least 5.0, at least 10. 
     In an embodiment, the composition comprises the polypeptide of the invention and one or more formulating agents, as described below. 
     The compositions may further comprise multiple enzymatic activities, such as one or more (e.g., several) enzymes selected from the group consisting of acetylxylan esterase, acylglycerol lipase, amylase, alpha-amylase, beta-amylase, arabinofuranosidase, cellobiohydrolases, cellulase, feruloyl esterase, galactanase, alpha-galactosidase, beta-galactosidase, beta-glucanase, beta-glucosidase, glucan 1,4-a-glucosidase, glucan 1,4-alpha-maltohydrolase, glucan 1,4-a-glucosidase, glucan 1,4-alpha-maltohydrolase, lysophospholipase, lysozyme, alpha-mannosidase, beta-mannosidase (mannanase), phytase, phospholipase A1, phospholipase A2, phospholipase D, protease, pullulanase, pectinesterase, triacylglycerol lipase, xylanase, beta-xylosidase or any combination thereof. 
     The compositions may further comprise one or more microbes. In an embodiment, the microbe is selected from the group consisting of  Bacillus subtilis, Bacillus licheniformis, Bacillus amyloliquefaciens, Bacillus cereus, Bacillus pumilus, Bacillus polymyxa, Bacillus megaterium, Bacillus coagulans, Bacillus circulans, Bifidobacterium bifidum, Bifidobacterium animalis, Bifidobacterium  sp.,  Carnobacterium  sp.,  Clostridium butyricum, Clostridium  sp.,  Enterococcus faecium, Enterococcus  sp.,  Lactobacillus  sp.,  Lactobacillus acidophilus, Lactobacillus farciminus, Lactobacillus rhamnosus, Lactobacillus reuteri, Lactobacillus salivarius, Lactococcus lactis, Lactococcus  sp.,  Leuconostoc  sp.,  Megasphaera elsdenii, Megasphaera  sp.,  Pediococcus acidilactici, Pediococcus  sp.,  Propionibacterium thoenii, Propionibacterium  sp. and  Streptococcus  sp. or any combination thereof. 
     In an embodiment, the composition comprises one or more formulating agents as disclosed herein, preferably one or more of the compounds selected from the list consisting of glycerol, ethylene glycol, 1, 2-propylene glycol or 1, 3-propylene glycol, sodium chloride, sodium benzoate, potassium sorbate, sodium sulfate, potassium sulfate, magnesium sulfate, sodium thiosulfate, calcium carbonate, sodium citrate, dextrin, glucose, sucrose, sorbitol, lactose, starch, kaolin and cellulose. 
     In an embodiment, the composition comprises one or more components selected from the list consisting of vitamins, minerals and amino acids. 
     In an embodiment, the composition comprises plant based material from the sub-family Panicoideae as disclosed herein, preferably maize, corn,  Sorghum , switchgrass, millet, pearl millet, foxtail millet or in a processed form such as milled corn, milled maize, defatted maize, defatted destarched maize, milled  Sorghum , milled switchgrass, milled millet, milled foxtail millet, milled pearl millet, or any combination thereof. 
     Formulation 
     The enzyme of the invention may be formulated as a liquid or a solid. For a liquid formulation, the formulating agent may comprise a polyol (such as e.g. glycerol, ethylene glycol or propylene glycol), a salt (such as e.g. sodium chloride, sodium benzoate, potassium sorbate) or a sugar or sugar derivative (such as e.g. dextrin, glucose, sucrose, and sorbitol). Thus in one embodiment, the composition is a liquid composition comprising the polypeptide of the invention and one or more formulating agents selected from the list consisting of glycerol, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, sodium chloride, sodium benzoate, potassium sorbate, dextrin, glucose, sucrose, and sorbitol. The liquid formulation may be sprayed onto the feed after it has been pelleted or may be added to drinking water given to the animals. 
     For a solid formulation, the formulation may be for example as a granule, spray dried powder or agglomerate (e.g. as disclosed in WO2000/70034). The formulating agent may comprise a salt (organic or inorganic zinc, sodium, potassium or calcium salts such as e.g. such as calcium acetate, calcium benzoate, calcium carbonate, calcium chloride, calcium citrate, calcium sorbate, calcium sulfate, potassium acetate, potassium benzoate, potassium carbonate, potassium chloride, potassium citrate, potassium sorbate, potassium sulfate, sodium acetate, sodium benzoate, sodium carbonate, sodium chloride, sodium citrate, sodium sulfate, zinc acetate, zinc benzoate, zinc carbonate, zinc chloride, zinc citrate, zinc sorbate, zinc sulfate), starch or a sugar or sugar derivative (such as e.g. sucrose, dextrin, glucose, lactose, sorbitol). 
     In one embodiment, the composition is a solid composition, such as a spray dried composition, comprising the xylanase of the invention and one or more formulating agents selected from the list consisting of sodium chloride, sodium benzoate, potassium sorbate, sodium sulfate, potassium sulfate, magnesium sulfate, sodium thiosulfate, calcium carbonate, sodium citrate, dextrin, glucose, sucrose, sorbitol, lactose, starch and cellulose. In a preferred embodiment, the formulating agent is selected from one or more of the following compounds: sodium sulfate, dextrin, cellulose, sodium thiosulfate, magnesium sulfate and calcium carbonate. 
     The present invention also relates to enzyme granules/particles comprising the xylanase of the invention optionally combined with one or more additional enzymes. The granule is composed of a core, and optionally one or more coatings (outer layers) surrounding the core. 
     Typically the granule/particle size, measured as equivalent spherical diameter (volume based average particle size), of the granule is 20-2000 μm, particularly 50-1500 μm, 100-1500 μm or 250-1200 μm. 
     The core can be prepared by granulating a blend of the ingredients, e.g., by a method comprising granulation techniques such as crystallization, precipitation, pan-coating, fluid bed coating, fluid bed agglomeration, rotary atomization, extrusion, prilling, spheronization, size reduction methods, drum granulation, and/or high shear granulation. 
     Methods for preparing the core can be found in Handbook of Powder Technology; Particle size enlargement by C. E. Capes; Volume 1; 1980; Elsevier. Preparation methods include known feed and granule formulation technologies, e.g.: 
     a) spray dried products, wherein a liquid enzyme-containing solution is atomized in a spray drying tower to form small droplets which during their way down the drying tower dry to form an enzyme-containing particulate material; 
     b) layered products, wherein the enzyme is coated as a layer around a pre-formed inert core particle, wherein an enzyme-containing solution is atomized, typically in a fluid bed apparatus wherein the pre-formed core particles are fluidized, and the enzyme-containing solution adheres to the core particles and dries up to leave a layer of dry enzyme on the surface of the core particle. Particles of a desired size can be obtained this way if a useful core particle of the desired size can be found. This type of product is described in, e.g., WO 97/23606; 
     c) absorbed core particles, wherein rather than coating the enzyme as a layer around the core, the enzyme is absorbed onto and/or into the surface of the core. Such a process is described in WO 97/39116. 
     d) extrusion or pelletized products, wherein an enzyme-containing paste is pressed to pellets or under pressure is extruded through a small opening and cut into particles which are subsequently dried. Such particles usually have a considerable size because of the material in which the extrusion opening is made (usually a plate with bore holes) sets a limit on the allowable pressure drop over the extrusion opening. Also, very high extrusion pressures when using a small opening increase heat generation in the enzyme paste, which is harmful to the enzyme; 
     e) prilled products, wherein an enzyme-containing powder is suspended in molten wax and the suspension is sprayed, e.g., through a rotating disk atomiser, into a cooling chamber where the droplets quickly solidify (Michael S. Showell (editor);  Powdered detergents ; Surfactant Science Series; 1998; vol. 71; page 140-142; Marcel Dekker). The product obtained is one wherein the enzyme is uniformly distributed throughout an inert material instead of being concentrated on its surface. Also U.S. Pat. Nos. 4,016,040 and 4,713,245 are documents relating to this technique; 
     f) mixer granulation products, wherein a liquid is added to a dry powder composition of, e.g., conventional granulating components, the enzyme being introduced either via the liquid or the powder or both. The liquid and the powder are mixed and as the moisture of the liquid is absorbed in the dry powder, the components of the dry powder will start to adhere and agglomerate and particles will build up, forming granulates comprising the enzyme. Such a process is described in U.S. Pat. No. 4,106,991 and related documents EP 170360, EP 304332, EP 304331, WO 90/09440 and WO 90/09428. In a particular product of this process wherein various high-shear mixers can be used as granulators, granulates consisting of enzyme as enzyme, fillers and binders etc. are mixed with cellulose fibres to reinforce the particles to give the so-called T-granulate. Reinforced particles, being more robust, release less enzymatic dust. 
     g) size reduction, wherein the cores are produced by milling or crushing of larger particles, pellets, tablets, briquettes etc. containing the enzyme. The wanted core particle fraction is obtained by sieving the milled or crushed product. Over and undersized particles can be recycled. Size reduction is described in (Martin Rhodes (editor); Principles of Powder Technology; 1990; Chapter 10; John Wiley &amp; Sons); 
     h) fluid bed granulation, which involves suspending particulates in an air stream and spraying a liquid onto the fluidized particles via nozzles. Particles hit by spray droplets get wetted and become tacky. The tacky particles collide with other particles and adhere to them and form a granule; 
     i) the cores may be subjected to drying, such as in a fluid bed drier. Other known methods for drying granules in the feed or detergent industry can be used by the skilled person. The drying preferably takes place at a product temperature of from 25 to 90° C. For some enzymes it is important the cores comprising the enzyme contain a low amount of water before coating. If water sensitive enzymes are coated before excessive water is removed, it will be trapped within the core and it may affect the activity of the enzyme negatively. After drying, the cores preferably contain 0.1-10% w/w water. 
     The core may include additional materials such as fillers, fibre materials (cellulose or synthetic fibres), stabilizing agents, solubilizing agents, suspension agents, viscosity regulating agents, light spheres, plasticizers, salts, lubricants and fragrances. 
     The core may include a binder, such as synthetic polymer, wax, fat, or carbohydrate. 
     The core may include a salt of a multivalent cation, a reducing agent, an antioxidant, a peroxide decomposing catalyst and/or an acidic buffer component, typically as a homogenous blend. 
     In one embodiment, the core comprises a material selected from the group consisting of salts (such as calcium acetate, calcium benzoate, calcium carbonate, calcium chloride, calcium citrate, calcium sorbate, calcium sulfate, potassium acetate, potassium benzoate, potassium carbonate, potassium chloride, potassium citrate, potassium sorbate, potassium sulfate, sodium acetate, sodium benzoate, sodium carbonate, sodium chloride, sodium citrate, sodium sulfate, zinc acetate, zinc benzoate, zinc carbonate, zinc chloride, zinc citrate, zinc sorbate, zinc sulfate), starch or a sugar or sugar derivative (such as e.g. sucrose, dextrin, glucose, lactose, sorbitol), sugar or sugar derivative (such as e.g. sucrose, dextrin, glucose, lactose, sorbitol), small organic molecules, starch, flour, cellulose and minerals and clay minerals (also known as hydrous aluminium phyllosilicates). In one embodiment, the core comprises a clay mineral such as kaolinite or kaolin. 
     The core may include an inert particle with the enzyme absorbed into it, or applied onto the surface, e.g., by fluid bed coating. 
     The core may have a diameter of 20-2000 μm, particularly 50-1500 μm, 100-1500 μm or 250-1200 μm. 
     The core may be surrounded by at least one coating, e.g., to improve the storage stability, to reduce dust formation during handling, or for coloring the granule. The optional coating(s) may include a salt and/or wax and/or flour coating, or other suitable coating materials. 
     The coating may be applied in an amount of at least 0.1% by weight of the core, e.g., at least 0.5%, 1% or 5%. The amount may be at most 100%, 70%, 50%, 40% or 30%. 
     The coating is preferably at least 0.1 μm thick, particularly at least 0.5 μm, at least 1 μm or at least 5 μm. In some embodiments the thickness of the coating is below 100 μm, such as below 60 μm, or below 40 μm. 
     The coating should encapsulate the core unit by forming a substantially continuous layer. A substantially continuous layer is to be understood as a coating having few or no holes, so that the core unit is encapsulated or enclosed with few or no uncoated areas. The layer or coating should in particular be homogeneous in thickness. 
     The coating can further contain other materials as known in the art, e.g., fillers, antisticking agents, pigments, dyes, plasticizers and/or binders, such as titanium dioxide, kaolin, calcium carbonate or talc. 
     A salt coating may comprise at least 60% by weight of a salt, e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or at least 99% by weight. 
     The salt may be added from a salt solution where the salt is completely dissolved or from a salt suspension wherein the fine particles are less than 50 μm, such as less than 10 μm or less than 5 μm. 
     The salt coating may comprise a single salt or a mixture of two or more salts. The salt may be water soluble, in particular having a solubility at least 0.1 g in 100 g of water at 20° C., preferably at least 0.5 g per 100 g water, e.g., at least 1 g per 100 g water, e.g., at least 5 g per 100 g water. 
     The salt may be an inorganic salt, e.g., salts of sulfate, sulfite, phosphate, phosphonate, nitrate, chloride or carbonate or salts of simple organic acids (less than 10 carbon atoms, e.g., 6 or less carbon atoms) such as citrate, malonate or acetate. Examples of cations in these salts are alkali or earth alkali metal ions, the ammonium ion or metal ions of the first transition series, such as sodium, potassium, magnesium, calcium, zinc or aluminium. Examples of anions include chloride, bromide, iodide, sulfate, sulfite, bisulfite, thiosulfate, phosphate, monobasic phosphate, dibasic phosphate, hypophosphite, dihydrogen pyrophosphate, tetraborate, borate, carbonate, bicarbonate, metasilicate, citrate, malate, maleate, malonate, succinate, sorbate, lactate, formate, acetate, butyrate, propionate, benzoate, tartrate, ascorbate or gluconate. In particular alkali- or earth alkali metal salts of sulfate, sulfite, phosphate, phosphonate, nitrate, chloride or carbonate or salts of simple organic acids such as citrate, malonate or acetate may be used. 
     The salt in the coating may have a constant humidity at 20° C. above 60%, particularly above 70%, above 80% or above 85%, or it may be another hydrate form of such a salt (e.g., anhydrate). The salt coating may be as described in WO1997/05245, WO1998/54980, WO1998/55599, WO2000/70034, WO2006/034710, WO2008/017661, WO2008/017659, WO2000/020569, WO2001/004279, WO1997/05245, WO2000/01793, WO2003/059086, WO2003/059087, WO2007/031483, WO2007/031485, WO2007/044968, WO2013/192043, WO2014/014647 and WO2015/197719 or polymer coating such as described in WO 2001/00042. 
     Specific examples of suitable salts are NaCl (CH20° C.=76%), Na2CO3 (CH20° C.=92%), NaNO3 (CH20° C.=73%), Na2HPO4 (CH20° C.=95%), Na3PO4 (CH25° C.=92%), NH4Cl (CH20° C.=79.5%), (NH4)2HPO4 (CH20° C.=93.0%), NH4H2PO4 (CH20° C.=93.1%), (NH4)2SO4 (CH20° C.=81.1%), KCl (CH20° C.=85%), K2HPO4 (CH20° C.=92%), KH2PO4 (CH20° C.=96.5%), KNO3 (CH20° C.=93.5%), Na2SO4 (CH20° C.=93%), K2SO4 (CH20° C.=98%), KHSO4 (CH20° C.=86%), MgSO4 (CH20° C.=90%), ZnSO4 (CH20° C.=90%) and sodium citrate (CH25° C.=86%). Other examples include NaH2PO4, (NH4)H2PO4, CuSO4, Mg(NO3)2, magnesium acetate, calcium acetate, calcium benzoate, calcium carbonate, calcium chloride, calcium citrate, calcium sorbate, calcium sulfate, potassium acetate, potassium benzoate, potassium carbonate, potassium chloride, potassium citrate, potassium sorbate, sodium acetate, sodium benzoate, sodium citrate, sodium sulfate, zinc acetate, zinc benzoate, zinc carbonate, zinc chloride, zinc citrate and zinc sorbate. 
     The salt may be in anhydrous form, or it may be a hydrated salt, i.e. a crystalline salt hydrate with bound water(s) of crystallization, such as described in WO 99/32595. Specific examples include anhydrous sodium sulfate (Na2SO4), anhydrous magnesium sulfate (MgSO4), magnesium sulfate heptahydrate (MgSO4.7H2O), zinc sulfate heptahydrate (ZnSO4.7H2O), sodium phosphate dibasic heptahydrate (Na2HPO4.7H2O), magnesium nitrate hexahydrate (Mg(NO3)2(6H2O)), sodium citrate dihydrate and magnesium acetate tetrahydrate. 
     Preferably the salt is applied as a solution of the salt, e.g., using a fluid bed. 
     A wax coating may comprise at least 60% by weight of a wax, e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or at least 99% by weight. 
     Specific examples of waxes are polyethylene glycols; polypropylenes; Carnauba wax; Candelilla wax; bees wax; hydrogenated plant oil or animal tallow such as polyethylene glycol (PEG), methyl hydroxy-propyl cellulose (MHPC), polyvinyl alcohol (PVA), hydrogenated ox tallow, hydrogenated palm oil, hydrogenated cotton seeds and/or hydrogenated soy bean oil; fatty acid alcohols; mono-glycerides and/or di-glycerides, such as glyceryl stearate, wherein stearate is a mixture of stearic and palmitic acid; micro-crystalline wax; paraffin&#39;s; and fatty acids, such as hydrogenated linear long chained fatty acids and derivatives thereof. A preferred wax is palm oil or hydrogenated palm oil. 
     The granule may comprise a core comprising the xylanase of the invention, one or more salt coatings and one or more wax coatings. Examples of enzyme granules with multiple coatings are shown in WO1993/07263, WO1997/23606 and WO2016/149636. 
     Non-dusting granulates may be produced, e.g., as disclosed in U.S. Pat. Nos. 4,106,991 and 4,661,452 and may optionally be coated by methods known in the art. The coating materials can be waxy coating materials and film-forming coating materials. Examples of waxy coating materials are poly(ethylene oxide) products (polyethyleneglycol, PEG) with mean molar weights of 1000 to 20000; ethoxylated nonylphenols having from 16 to 50 ethylene oxide units; ethoxylated fatty alcohols in which the alcohol contains from 12 to 20 carbon atoms and in which there are 15 to 80 ethylene oxide units; fatty alcohols; fatty acids; and mono- and di- and triglycerides of fatty acids. Examples of film-forming coating materials suitable for application by fluid bed techniques are given in GB 1483591. 
     The granulate may further comprise one or more additional enzymes. Each enzyme will then be present in more granules securing a more uniform distribution of the enzymes, and also reduces the physical segregation of different enzymes due to different particle sizes. Methods for producing multi-enzyme co-granulates is disclosed in the ip.com disclosure IPCOM000200739D. 
     Another example of formulation of enzymes by the use of co-granulates is disclosed in WO 2013/188331. 
     The present invention also relates to protected enzymes prepared according to the method disclosed in EP 238,216. 
     Thus, in a further aspect, the present invention provides a granule, which comprises: 
     (a) a core comprising an xylanase according to the invention, and 
     (b) a coating consisting of one or more layer(s) surrounding the core. 
     In one embodiment, the coating comprises a salt coating as described herein. In one embodiment, the coating comprises a wax coating as described herein. In one embodiment, the coating comprises a salt coating followed by a wax coating as described herein. 
     Animal Feed Additives 
     The present invention also relates to animal feed compositions and animal feed additives comprising one or more xylanases of the invention. In an embodiment, the animal feed or animal feed additive comprises a formulating agent and one or more xylanases of the invention. In a further embodiment, the formulating agent comprises one or more of the following compounds: glycerol, ethylene glycol, 1, 2-propylene glycol or 1, 3-propylene glycol, sodium chloride, sodium benzoate, potassium sorbate, sodium sulfate, potassium sulfate, magnesium sulfate, sodium thiosulfate, calcium carbonate, sodium citrate, dextrin, glucose, sucrose, sorbitol, lactose, starch and cellulose. 
     Thus the invention further relates to an animal feed additive comprising one or more vitamins and a xylanase variant of the invention. The invention also relates to an animal feed additive comprising one or more minerals and a xylanase variant of the invention. The invention also relates to an animal feed additive comprising one or more amino acids and a xylanase variant of the invention. 
     In an embodiment, the amount of enzyme in the animal feed additive is between 0.001% and 10% by weight of the composition. 
     In an embodiment, the animal feed additive comprises one or more formulating agents, preferably as described herein above. 
     In an embodiment, the animal feed additive comprises one or more additional enzymes, preferably as described herein below. 
     In an embodiment, the animal feed additive comprises one or more probiotics, preferably as described herein below. 
     In an embodiment, the animal feed additive comprises one or more vitamins, preferably as described herein below. 
     In an embodiment, the animal feed additive comprises one or more minerals, preferably as described herein below. 
     In an embodiment, the animal feed additive comprises one or more amino acids, preferably as described herein below. 
     In an embodiment, the animal feed additive comprises one or more prebiotics, preferably as described herein below. 
     In an embodiment, the animal feed additive comprises one or more organic acids, preferably as described herein below. 
     In an embodiment, the animal feed additive comprises one or more phytogenics, preferably as described herein below. 
     Animal Feed 
     The present invention also relates to animal feed compositions comprising one or more xylanase variants of the invention. The invention also relates to an animal feed comprising the granule as described herein and plant based material. The invention also relates to an animal feed comprising the animal feed additive as described herein and plant based material. In one embodiment, the plant based material is from the sub-family Panicoideae. 
     Animal feed compositions or diets have a relatively high content of protein. Poultry and pig diets can be characterised as indicated in Table B of WO 01/58275, columns 2-3. Fish diets can be characterised as indicated in column 4 of this Table B. Furthermore such fish diets usually have a crude fat content of 200-310 g/kg. 
     An animal feed composition according to the invention has a crude protein content of 50-800 g/kg, and furthermore comprises at least one xylanase as claimed herein. 
     Furthermore, or in the alternative (to the crude protein content indicated above), the animal feed composition of the invention has a content of metabolisable energy of 10-30 MJ/kg; and/or a content of calcium of 0.1-200 g/kg; and/or a content of available phosphorus of 0.1-200 g/kg; and/or a content of methionine of 0.1-100 g/kg; and/or a content of methionine plus cysteine of 0.1-150 g/kg; and/or a content of lysine of 0.5-50 g/kg. 
     In particular embodiments, the content of metabolisable energy, crude protein, calcium, phosphorus, methionine, methionine plus cysteine, and/or lysine is within any one of ranges 2, 3, 4 or 5 in Table B of WO 01/58275 (R. 2-5). 
     Crude protein is calculated as nitrogen (N) multiplied by a factor 6.25, i.e. Crude protein (g/kg)=N (g/kg)×6.25. The nitrogen content is determined by the Kjeldahl method (A.O.A.C., 1984, Official Methods of Analysis 14th ed., Association of Official Analytical Chemists, Washington D.C.). 
     Metabolisable energy can be calculated on the basis of the NRC publication Nutrient requirements in swine, ninth revised edition 1988, subcommittee on swine nutrition, committee on animal nutrition, board of agriculture, national research council. National Academy Press, Washington, D.C., pp. 2-6, and the European Table of Energy Values for Poultry Feed-stuffs, Spelderholt centre for poultry research and extension, 7361 DA Beekbergen, The Netherlands. Grafisch bedrijf Ponsen &amp; Iooijen bv, Wageningen. ISBN 90-71463-12-5. 
     The dietary content of calcium, available phosphorus and amino acids in complete animal diets is calculated on the basis of feed tables such as Veevoedertabel 1997, gegevens over chemische samenstelling, verteerbaarheid en voederwaarde van voedermiddelen, Central Veevoederbureau, Runderweg 6, 8219 pk Lelystad. ISBN 90-72839-13-7. 
     In a particular embodiment, the animal feed composition of the invention contains at least one vegetable protein as defined above. 
     The animal feed composition of the invention may also contain animal protein, such as Meat and Bone Meal, Feather meal, and/or Fish Meal, typically in an amount of 0-25%. The animal feed composition of the invention may also comprise Dried Distillers Grains with Solubles (DDGS), typically in amounts of 0-30%. 
     In still further particular embodiments, the animal feed composition of the invention contains 0-80% maize; and/or 0-80%  Sorghum ; and/or 0-70% wheat; and/or 0-70% Barley; and/or 0-30% oats; and/or 0-40% soybean meal; and/or 0-25% fish meal; and/or 0-25% meat and bone meal; and/or 0-20% whey. 
     The animal feed may comprise vegetable proteins. In particular embodiments, the protein content of the vegetable proteins is at least 10, 20, 30, 40, 50, 60, 70, 80, or 90% (w/w). Vegetable proteins may be derived from vegetable protein sources, such as legumes and cereals, for example, materials from plants of the families Fabaceae (Leguminosae), Cruciferaceae, Chenopodiaceae, and Poaceae, such as soy bean meal, lupin meal, rapeseed meal, and combinations thereof. 
     In a particular embodiment, the vegetable protein source is material from one or more plants of the family Fabaceae, e.g., soybean, lupine, pea, or bean. In another particular embodiment, the vegetable protein source is material from one or more plants of the family Chenopodiaceae, e.g. beet, sugar beet, spinach or  quinoa . Other examples of vegetable protein sources are rapeseed, and cabbage. In another particular embodiment, soybean is a preferred vegetable protein source. Other examples of vegetable protein sources are cereals such as barley, wheat, rye, oat, maize (corn), rice, and  Sorghum.    
     Animal diets can e.g. be manufactured as mash feed (non-pelleted) or pelleted feed. Typically, the milled feed-stuffs are mixed and sufficient amounts of essential vitamins and minerals are added according to the specifications for the species in question. Enzymes can be added as solid or liquid enzyme formulations. For example, for mash feed a solid or liquid enzyme formulation may be added before or during the ingredient mixing step. For pelleted feed the (liquid or solid) xylanase/enzyme preparation may also be added before or during the feed ingredient step. Typically a liquid xylanase/enzyme preparation comprises the xylanase of the invention optionally with a polyol, such as glycerol, ethylene glycol or propylene glycol, and is added after the pelleting step, such as by spraying the liquid formulation onto the pellets. The enzyme may also be incorporated in a feed additive or premix. 
     Alternatively, the xylanase can be prepared by freezing a mixture of liquid enzyme solution with a bulking agent such as ground soybean meal, and then lyophilizing the mixture. 
     The final enzyme concentration in the diet is within the range of 0.01-200 mg enzyme protein per kg diet, preferably between 0.05-100 mg/kg diet, more preferably 0.1-50 mg, even more preferably 0.2-20 mg enzyme protein per kg animal diet. 
     It is at present contemplated that the enzyme is administered in one or more of the following amounts (dosage ranges): 0.01-200; 0.05-100; 0.1-50; 0.2-20; 0.1-1; 0.2-2; 0.5-5; or 1-10; —all these ranges being in mg xylanase protein per kg feed (ppm). 
     For determining mg xylanase protein per kg feed, the xylanase is purified from the feed composition, and the specific activity of the purified xylanase is determined using a relevant assay (see under xylanase activity). The xylanase activity of the feed composition as such is also determined using the same assay, and on the basis of these two determinations, the dosage in mg xylanase protein per kg feed is calculated. 
     In a particular embodiment, the animal feed additive of the invention is intended for being included (or prescribed as having to be included) in animal diets or feed at levels of 0.01 to 10.0%; more particularly 0.05 to 5.0%; or 0.2 to 1.0% (% meaning g additive per 100 g feed). This is so in particular for premixes. 
     The same principles apply for determining mg xylanase protein in feed additives. Of course, if a sample is available of the xylanase used for preparing the feed additive or the feed, the specific activity is determined from this sample (no need to purify the xylanase from the feed composition or the additive). 
     Plant Based Material from the Sub-Family Panicoideae 
     In one embodiment, the plant based material from the sub-family Panicoideae is from the tribe Andropogoneae such as the rank  Andropogon  or  Andropterum  or  Apluda  or  Apocopis  or  Arthraxon  or  Bothriochloa  or  Capillipedium  or  Chionachne  or  Chrysopogon  or  Coelorachis  or  Coix  or  Cymbopogon  or  Dichanthium  or  Diheteropogon  or  Dimeria  or  Elionurus  or  Eremochloa  or  Euclasta  or  Eulalia  or  Germainia  or  Hemarthria  or  Heteropholis  or  Heteropogon  or  Hyparrhenia  or  Hyperthelia  or  Imperata  or  Ischaemum  or  Iseilema  or  Kerriochloa  or  Microstegium  or  Miscanthidium  or  Miscanthus  or  Mnesithea  or  Ophiuros  or  Oxyrhachis  or  Phacelurus  or  Pholiurus  or  Pogonatherum  or  Polytoca  or  Polytrias  or  Pseudopogonatherum  or  Pseudosorghum  or  Rhytachne  or  Rottboellia  or  Saccharum  (e.g. sugar cane) or  Sarga  or  Schizachyrium  or  Sehima  or  Sorghastrum  or  Sorghum  or  Spodiopogon  or  Thaumastochloa  or  Thelepogon  or  Themeda  or  Trachypogon  or  Triarrhena  or  Tripsacum  or  Urelytrum  or  Vetiveria  or  Vossia  or  Xerochloa  or  Zea.    
     In a preferred embodiment, the plant based material from the sub-family Panicoideae is from the rank  Zea , such as the species  Zea diploperennis, Zea luxurians, Zea mays, Zea nicaraguensis  or  Zea perennis.    
     In a preferred embodiment, the plant based material from the sub-family Panicoideae is from the rank  Sorghum , such as the species  Sorghum amplum, Sorghum angustum, Sorghum arundinaceum, Sorghum australiense, Sorghum bicolor, Sorghum brachypodum, Sorghum bulbosum, Sorghum ecarinatum, Sorghum exstans, Sorghum grande, Sorghum halepense, Sorghum  hybrid cultivar,  Sorghum interjectum, Sorghum intrans, Sorghum laxiflorum, Sorghum leiocladum, Sorghum macrospermum, Sorghum matarankense, Sorghum nitidum, Sorghum plumosum, Sorghum propinquum, Sorghum purpureosericeum, Sorghum stipoideum, Sorghum sudanense, Sorghum timorense, Sorghum versicolor, Sorghum  sp. ‘Silk’ or  Sorghum  sp. as defined in WO2007/002267. 
     In another embodiment, the plant based material from the sub-family Panicoideae is from the tribe Paniceae such as the rank  Acritochaete, Acroceras, Alexfloydia, Alloteropsis, Amphicarpum, Ancistrachne, Anthephora, Brachiaria  (e.g. signal grass),  Calyptochloa, Cenchrus, Chaetium, Chaetopoa, Chamaeraphis, Chlorocalymma, Cleistochloa, Cyphochlaena, Cyrtococcum, Dichanthelium, Digitaria, Dissochondrus, Echinochloa, Entolasia, Eriochloa, Homopholis, Hygrochloa, Hylebates, Ixophorus, Lasiacis, Leucophrys, Louisiella, Megaloprotachne, Megathyrsus, Melinis, Microcalamus, Moorochloa, Neurachne, Odontelytrum, Oplismenus, Ottochloa, Panicum, Paractaenum, Paraneurachne, Paratheria, Parodiophyllochloa, Paspalidium, Pennisetum, Plagiosetum, Poecilostachys, Pseudechinolaena, Pseudochaetochloa, Pseudoraphis, Rupichloa, Sacciolepis, Scutachne, Setaria, Setariopsis, Snowdenia, Spinifex, Stenotaphrum, Stereochlaena, Thrasya, Thuarea, Thyridolepis, Tricholaena , unclassified Paniceae,  Uranthoecium, Urochloa  (e.g. signal grass),  Walwhalleya, Whiteochloa, Yakirra, Yvesia, Zuloagaea  or  Zygochloa.    
     In a preferred embodiment, the plant based material from the sub-family Panicoideae is from the rank  Panicum , such as the species  Panicum adenophorum, Panicum  aff.  aquaticum  JKT-2012,  Panicum amarum, Panicum antidotale, Panicum aquaticum, Panicum arctum, Panicum arundinariae, Panicum atrosanguineum, Panicum auricomum, Panicum auritum, Panicum bartlettii, Panicum bergii, Panicum bisulcatum, Panicum boliviense, Panicum brazzavillense, Panicum brevifolium, Panicum caaguazuense, Panicum campestre, Panicum capillare, Panicum cayennense, Panicum cayoense, Panicum cervicatum, Panicum chloroleucum, Panicum claytonii, Panicum coloratum, Panicum cyanescens, Panicum decompositum, Panicum deustum, Panicum dichotomiflorum, Panicum dinklagei, Panicum distichophyllum, Panicum dregeanum, Panicum elephantipes, Panicum fauriei, Panicum flexile, Panicum fluviicola, Panicum gouinii, Panicum gracilicaule, Panicum granuliferum, Panicum guatemalense, Panicum hallii, Panicum heterostachyum, Panicum hirticaule, Panicum hirtum, Panicum hylaeicum, Panicum incumbens, Panicum infestum, Panicum italicum, Panicum laetum, Panicum laevinode, Panicum lanipes, Panicum larcomianum, Panicum longipedicellatum, Panicum machrisianum, Panicum malacotrichum, Panicum margaritiferum, Panicum micranthum, Panicum miliaceum, Panicum milioides, Panicum millegrana, Panicum mystasipum, Panicum natalense, Panicum nephelophilum, Panicum nervosum, Panicum notatum, Panicum olyroides, Panicum paludosum, Panicum pansum, Panicum pantrichum, Panicum parvifolium, Panicum parviglume, Panicum pedersenii, Panicum penicillatum, Panicum petersonii, Panicum phragmitoides, Panicum piauiense, Panicum pilosum, Panicum pleianthum, Panicum polycomum, Panicum polygonatum, Panicum pseudisachne, Panicum pygmaeum, Panicum pyrularium, Panicum queenslandicum, Panicum racemosum, Panicum repens, Panicum rhizogonum, Panicum rigidulum, Panicum rivale, Panicum rude, Panicum rudgei, Panicum schinzii, Panicum schwackeanum, Panicum sellowii, Panicum seminudum, Panicum stapfianum, Panicum stenodes, Panicum stramineum, Panicum subalbidum, Panicum subtiramulosum, Panicum sumatrense, Panicum tenellum, Panicum tenuifolium, Panicum trichanthum, Panicum trichidiachne, Panicum trichoides, Panicum tricholaenoides, Panicum tuerckheimii, Panicum turgidum, Panicum urvilleanum, Panicum validum, Panicum venezuelae, Panicum verrucosum, Panicum virgatum, Panicum wettsteinii, Panicum  sp.,  Panicum  sp. Christin 16-200,  Panicum  sp. ELS-2011,  Panicum  sp. EM389 or  Panicum  sp. Forest 761. 
     In a further embodiment, the plant based material from the sub-family Panicoideae is maize ( Zea ), corn ( Zea ),  Sorghum  ( Sorghum ), switchgrass ( Panicum virgatum ), millet ( Panicum miliaceum ), pearl millet ( Cenchrus violaceus  also called  Pennisetum glaucum ), foxtail millet ( Setaria italica  also called  Panicum italicum ) or in a processed form such as milled corn, milled maize, defatted maize, defatted destarched maize, milled  Sorghum , milled switchgrass, milled millet, milled foxtail millet, milled pearl millet, or any combination thereof. 
     In an embodiment, the plant based material from the sub-family Panicoideae is from the seed of the plant. In a preferred embodiment, the plant based material from the sub-family Panicoideae is from the seed of maize ( Zea ), corn ( Zea ),  Sorghum  ( Sorghum ), switchgrass ( Panicum virgatum ), millet ( Panicum miliaceum ), pearl millet ( Cenchrus violaceus  also called  Pennisetum glaucum ), foxtail millet ( Setaria italica  also called  Panicum italicum ) or wherein the seed has been processed such as milled corn, milled maize, defatted maize, defatted destarched maize, milled  Sorghum , milled switchgrass, milled millet, milled foxtail millet, milled pearl millet, or any combination thereof. 
     Additional Enzymes 
     In another embodiment, the compositions described herein optionally include one or more enzymes. Enzymes can be classified on the basis of the handbook Enzyme Nomenclature from NC-IUBMB, 1992), see also the ENZYME site at the internet: http://www.expasy.ch/enzyme/. ENZYME is a repository of information relative to the nomenclature of enzymes. It is primarily based on the recommendations of the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (IUB-MB), Academic Press, Inc., 1992, and it describes each type of characterized enzyme for which an EC (Enzyme Commission) number has been provided (Bairoch A. The ENZYME database, 2000, Nucleic Acids Res 28:304-305). This IUB-MB Enzyme nomenclature is based on their substrate specificity and occasionally on their molecular mechanism; such a classification does not reflect the structural features of these enzymes. 
     Another classification of certain glycoside hydrolase enzymes, such as endoglucanase, galactanase, mannanase, dextranase, lysozyme and galactosidase is described in Henrissat et al, “The carbohydrate-active enzymes database (CAZy) in 2013 ”, Nucl. Acids Res . (1 Jan. 2014) 42 (D1): D490-D495; see also www.cazy.org. 
     Thus the composition of the invention may also comprise at least one other enzyme selected from the group comprising of acetylxylan esterase (EC 3.1.1.23), acylglycerol lipase (EC 3.1.1.72), alpha-amylase (EC 3.2.1.1), beta-amylase (EC 3.2.1.2), arabinofuranosidase (EC 3.2.1.55), cellobiohydrolases (EC 3.2.1.91), cellulase (EC 3.2.1.4), feruloyl esterase (EC 3.1.1.73), galactanase (EC 3.2.1.89), alpha-galactosidase (EC 3.2.1.22), beta-galactosidase (EC 3.2.1.23), glucan 1,4-a-glucosidase (glucoamylase) (EC 3.2.1.3), glucan 1,4-alpha-maltohydrolase (maltogenic alpha-amylase) (EC 3.2.1.133), beta-glucanase (EC 3.2.1.6), beta-glucosidase (EC 3.2.1.21), triacylglycerol lipase (EC 3.1.1.3), lysophospholipase (EC 3.1.1.5), lysozyme (EC 3.2.1.17), alpha-mannosidase (EC 3.2.1.24), beta-mannosidase (mannanase) (EC 3.2.1.25), phytase (EC 3.1.3.8, EC 3.1.3.26, EC 3.1.3.72), phospholipase A1 (EC 3.1.1.32), phospholipase A2 (EC 3.1.1.4), phospholipase D (EC 3.1.4.4), protease (EC 3.4), pullulanase (EC 3.2.1.41), pectinesterase (EC 3.1.1.11), xylanase (EC 3.2.1.8, EC 3.2.1.136), beta-xylosidase (EC 3.2.1.37), or any combination thereof. 
     In a particular embodiment the composition of the invention comprises an alpha-galactosidase (EC 3.2.1.22). 
     In a particular embodiment, the composition of the invention comprises a phytase (EC 3.1.3.8 or 3.1.3.26). Examples of commercially available phytases include Bio-Feed™ Phytase (Novozymes), Ronozyme® P, Ronozyme® NP and Ronozyme® HiPhos (DSM Nutritional Products), Natuphos™ (BASF), Natuphos™ E (BASF), Finase® and Quantum® Blue (AB Enzymes), OptiPhos® (Huvepharma), AveMix® Phytase (Aveve Biochem), Phyzyme® XP (Verenium/DuPont) and Axtra® PHY (DuPont). Other preferred phytases include those described in e.g. WO 98/28408, WO 00/43503, and WO 03/066847. 
     In a particular embodiment, the composition of the invention comprises a xylanase (EC 3.2.1.8). Examples of commercially available xylanases include Ronozyme® WX (DSM Nutritional Products), Econase® XT and Barley (AB Vista), Xylathin® (Verenium), Hostazym® X (Huvepharma), Axtra® XB (Xylanase/beta-glucanase, DuPont) and Axtra® XAP (Xylanase/amylase/protease, DuPont), AveMix® XG 10 (xylanase/glucanase) and AveMix® 02 CS (xylanase/glucanase/pectinase, Aveve Biochem), and Naturgrain (BASF). 
     In a particular embodiment, the composition of the invention comprises a protease (EC 3.4). Examples of commercially available proteases include Ronozyme® ProAct (DSM Nutritional Products), Poultrygrow™ (Jefo) and Cibenza® DP100 and Cibenza® IND900 (Novus). 
     In a particular embodiment, the composition of the invention comprises an alpha-amylase (EC 3.2.1.1). Examples of commercially available alpha-amylases include Ronozyme® A and RONOZYME® RumiStar™ (DSM Nutritional Products). 
     In one embodiment, the composition of the invention comprises a multicomponent enzyme product, such as FRA® Octazyme (Framelco), Ronozyme® G2, Ronozyme® VP and Ronozyme® MultiGrain (DSM Nutritional Products), Rovabio® Excel or Rovabio® Advance (Adisseo). 
     Eubiotics 
     Eubiotics are compounds which are designed to give a healthy balance of the micro-flora in the gastrointestinal tract. Eubiotics cover a number of different feed additives, such as probiotics, prebiotics, phytogenics (essential oils) and organic acids which are described in more detail below. 
     Probiotics 
     In an embodiment, the animal feed composition further comprises one or more additional probiotic. In a particular embodiment, the animal feed composition further comprises a bacterium from one or more of the following genera:  Lactobacillus, Lactococcus, Streptococcus, Bacillus, Pediococcus, Enterococcus, Leuconostoc, Carnobacterium, Propionibacterium, Bifidobacterium, Clostridium, Saccharomyces, Pediococcus  and  Megasphaera  or any combination thereof. 
     In a preferred embodiment, animal feed composition further comprises a bacterium from one or more of the following strains:  Bacillus subtilis, Bacillus licheniformis, Bacillus amyloliquefaciens, Bacillus cereus, Bacillus pumilus, Bacillus polymyxa, Bacillus megaterium, Bacillus coagulans, Bacillus circulans, Enterococcus faecium, Enterococcus  spp, and  Pediococcus  spp,  Lactobacillus  spp,  Bifidobacterium  spp,  Lactobacillus acidophilus, Pediococsus acidilactici, Lactococcus lactis, Bifidobacterium bifidum, Propionibacterium thoenii, Lactobacillus farciminus, Lactobacillus rhamnosus, Clostridium butyricum, Bifidobacterium animalis  ssp.  animalis, Lactobacillus reuteri, Lactobacillus salivarius  ssp.  salivarius, Megasphaera elsdenii, Propionibacteria  sp,  Saccharomyces cerevisiae, Saccharomyces cerevisiae boulardii, Pediococcus acidilactici.    
     In a more preferred embodiment, composition, animal feed additive or animal feed further comprises a bacterium from one or more of the following strains of  Bacillus subtilis:  3A-P4 (PTA-6506), 15A-P4 (PTA-6507), 22C-P1 (PTA-6508), 2084 (NRRL B-500130), LSSA01 (NRRL-B-50104), BS27 (NRRL B-501 05), BS 18 (NRRL B-50633), BS 278 (NRRL B-50634), DSM 29870, DSM 29871, DSM 32315, NRRL B-50136, NRRL B-50605, NRRL B-50606, NRRL B-50622 and PTA-7547. 
     In a more preferred embodiment, composition, animal feed additive or animal feed further comprises a bacterium from one or more of the following strains of  Bacillus pumilus : NRRL B-50016, ATCC 700385, NRRL B-50885 or NRRL B-50886. 
     In a more preferred embodiment, composition, animal feed additive or animal feed further comprises a bacterium from one or more of the following strains of  Bacillus licheniformis : NRRL B 50015, NRRL B-50621 or NRRL B-50623. 
     In a more preferred embodiment, composition, animal feed additive or animal feed further comprises a bacterium from one or more of the following strains of  Bacillus amyloliquefaciens : DSM 29869, DSM 29869, NRRL B 50607, PTA-7543, PTA-7549, NRRL B-50349, NRRL B-50606, NRRL B-50013, NRRL B-50151, NRRL B-50141, NRRL B-50147 or NRRL B-50888. 
     The bacterial count of each of the bacterial strains in the animal feed composition is between 1×10 4  and 1×10 14  CFU/kg of dry matter, preferably between 1×10 6  and 1×10 12  CFU/kg of dry matter, and more preferably between 1×10 7  and 1×10 11  CFU/kg of dry matter. In a more preferred embodiment the bacterial count of each of the bacterial strains in the animal feed composition is between 1×10 8  and 1×10 10  CFU/kg of dry matter. 
     The bacterial count of each of the bacterial strains in the animal feed composition is between 1×10 5  and 1×10 15  CFU/animal/day, preferably between 1×10 7  and 1×10 13  CFU/animal/day, and more preferably between 1×10 8  and 1×10 12  CFU/animal/day. In a more preferred embodiment the bacterial count of each of the bacterial strains in the animal feed composition is between 1×10 9  and 1×10 11  CFU/animal/day. In one embodiment, the amount of probiotics is 0.001% to 10% by weight of the composition. 
     In another embodiment, the one or more bacterial strains are present in the form of a stable spore. 
     Examples of commercial products are Cylactin® (DSM Nutritional Products), Alterion (Adisseo), Enviva PRO (DuPont Animal Nutrition), Syncra® (mix enzyme+probiotic, DuPont Animal Nutrition), Ecobiol® and Fecinor® (Norel/Evonik), GutCare® PY1 (Evonik) Levucell SB, Levucell SC Ruminant and Bactocell (Lallamand). 
     Prebiotics 
     Prebiotics are substances that induce the growth or activity of microorganisms (e.g., bacteria and fungi) that contribute to the well-being of their host. Prebiotics are typically non-digestible fiber compounds that pass undigested through the upper part of the gastrointestinal tract and stimulate the growth or activity of advantageous bacteria that colonize the large bowel by acting as substrate for them. Normally, prebiotics increase the number or activity of bifidobacteria and lactic acid bacteria in the GI tract. 
     Yeast derivatives (inactivated whole yeasts or yeast cell walls) can also be considered as prebiotics. They often comprise mannan-oligosaccharides, yeast beta-glucans or protein contents and are normally derived from the cell wall of the yeast,  Saccharomyces cerevisiae.    
     In one embodiment, the amount of prebiotics is 0.001% to 10% by weight of the composition. Examples of yeast products are Yang® and Agrimos (Lallemand Animal Nutrition). 
     Phytogenics 
     Phytogenics are a group of natural growth promoters or non-antibiotic growth promoters used as feed additives, derived from herbs, spices or other plants. Phytogenics can be single substances prepared from essential oils/extracts, essential oils/extracts, single plants and mixture of plants (herbal products) or mixture of essential oils/extracts/plants (specialized products). 
     Examples of phytogenics are rosemary, sage, oregano, thyme, clove, and lemongrass. Examples of essential oils are thymol, eugenol, meta-cresol, vaniline, salicylate, resorcine, guajacol, gingerol, lavender oil, ionones, irone, eucalyptol, menthol, peppermint oil, alpha-pinene; limonene, anethol, linalool, methyl dihydrojasmonate, carvacrol, propionic acid/propionate, acetic acid/acetate, butyric acid/butyrate, rosemary oil, clove oil, geraniol, terpineol, citronellol, amyl and/or benzyl salicylate, cinnamaldehyde, plant polyphenol (tannin), turmeric and  curcuma  extract. 
     In one embodiment, the amount of phytogenics is 0.001% to 10% by weight of the composition. Examples of commercial products are Crina® (DSM Nutritional Products); Cinergy™, Biacid™, ProHacid™ Classic and ProHacid™ Advance™ (all Promivi/Cargill) and Envivo EO (DuPont Animal Nutrition). 
     Organic Acids 
     Organic acids (C1-C7) are widely distributed in nature as normal constituents of plants or animal tissues. They are also formed through microbial fermentation of carbohydrates mainly in the large intestine. They are often used in swine and poultry production as a replacement of antibiotic growth promoters since they have a preventive effect on the intestinal problems like necrotic enteritis in chickens and  Escherichia coli  infection in young pigs. Organic acids can be sold as mono component or mixtures of typically 2 or 3 different organic acids. Examples of organic acids are propionic acid, formic acid, citric acid, lactic acid, sorbic acid, malic acid, acetic acid, fumaric acid, benzoic acid, butyric acid and tartaric acid or their salt (typically sodium or potassium salt such as potassium diformate or sodium butyrate). 
     In one embodiment, the amount of organic acid is 0.001% to 10% by weight of the composition. Examples of commercial products are VevoVitall® (DSM Nutritional Products), Amasil®, Luprisil®, Lupro-Grain®, Lupro-Cid®, Lupro-Mix® (BASF), n-Butyric Acid AF (OXEA) and Adimix Precision (Nutriad) and Porcinat™ and Gallinat+™ (Jefo). 
     Premix 
     The incorporation of the composition of feed additives as exemplified herein above to animal feeds, for example poultry feeds, is in practice carried out using a concentrate or a premix. A premix designates a preferably uniform mixture of one or more microingredients with diluent and/or carrier. Premixes are used to facilitate uniform dispersion of micro-ingredients in a larger mix. A premix according to the invention can be added to feed ingredients or to the drinking water as solids (for example as water soluble powder) or liquids. 
     Amino Acids 
     The composition of the invention may further comprise one or more amino acids. Examples of amino acids which are used in animal feed are lysine, alanine, beta-alanine, threonine, methionine and tryptophan. In one embodiment, the amount of amino acid is 0.001% to 10% by weight of the composition. 
     Vitamins and Minerals 
     In another embodiment, the animal feed may include one or more vitamins, such as one or more fat-soluble vitamins and/or one or more water-soluble vitamins. In another embodiment, the animal feed may optionally include one or more minerals, such as one or more trace minerals and/or one or more macro minerals. 
     Usually fat- and water-soluble vitamins, as well as trace minerals form part of a so-called premix intended for addition to the feed, whereas macro minerals are usually separately added to the feed. 
     Non-limiting examples of fat-soluble vitamins include vitamin A, vitamin D3, vitamin E, and vitamin K, e.g., vitamin K3. 
     Non-limiting examples of water-soluble vitamins include vitamin C, vitamin B12, biotin and choline, vitamin B1, vitamin B2, vitamin B6, niacin, folic acid and panthothenate, e.g., Ca-D-panthothenate. 
     Non-limiting examples of trace minerals include boron, cobalt, chloride, chromium, copper, fluoride, iodine, iron, manganese, molybdenum, iodine, selenium and zinc. 
     Non-limiting examples of macro minerals include calcium, magnesium, phosphorus, potassium and sodium. 
     In one embodiment, the amount of vitamins is 0.001% to 10% by weight of the composition. In one embodiment, the amount of minerals is 0.001% to 10% by weight of the composition. 
     The nutritional requirements of these components (exemplified with poultry and piglets/pigs) are listed in Table A of WO 01/58275. Nutritional requirement means that these components should be provided in the diet in the concentrations indicated. 
     In the alternative, the animal feed additive of the invention comprises at least one of the individual components specified in Table A of WO 01/58275. At least one means either of, one or more of, one, or two, or three, or four and so forth up to all thirteen, or up to all fifteen individual components. More specifically, this at least one individual component is included in the additive of the invention in such an amount as to provide an in-feed-concentration within the range indicated in column four, or column five, or column six of Table A. 
     In a still further embodiment, the animal feed additive of the invention comprises at least one of the below vitamins, preferably to provide an in-feed-concentration within the ranges specified in the below Table 1 (for piglet diets, and broiler diets, respectively). 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Typical vitamin recommendations 
               
            
           
           
               
               
               
            
               
                 Vitamin 
                 Piglet diet 
                 Broiler diet 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 Vitamin A 
                 10,000-15,000 
                 IU/kg feed 
                 8-12,500 
                 IU/kg feed 
               
               
                 Vitamin D3 
                 1800-2000 
                 IU/kg feed 
                 3000-5000 
                 IU/kg feed 
               
               
                 Vitamin E 
                 60-100 
                 mg/kg feed 
                 150-240 
                 mg/kg feed 
               
               
                 Vitamin K3 
                 2-4 
                 mg/kg feed 
                 2-4 
                 mg/kg feed 
               
               
                 Vitamin B1 
                 2-4 
                 mg/kg feed 
                 2-3 
                 mg/kg feed 
               
               
                 Vitamin B2 
                 6-10 
                 mg/kg feed 
                 7-9 
                 mg/kg feed 
               
               
                 Vitamin B6 
                 4-8 
                 mg/kg feed 
                 3-6 
                 mg/kg feed 
               
               
                 Vitamin B12 
                 0.03-0.05 
                 mg/kg feed 
                 0.015-0.04 
                 mg/kg feed 
               
               
                 Niacin 
                 30-50 
                 mg/kg feed 
                 50-80 
                 mg/kg feed 
               
               
                 (Vitamin B3) 
               
               
                 Pantothenic 
                 20-40 
                 mg/kg feed 
                 10-18 
                 mg/kg feed 
               
               
                 acid 
               
               
                 Folic acid 
                 1-2 
                 mg/kg feed 
                 1-2 
                 mg/kg feed 
               
               
                 Biotin 
                 0.15-0.4 
                 mg/kg feed 
                 0.15-0.3 
                 mg/kg feed 
               
               
                 Choline 
                 200-400 
                 mg/kg feed 
                 300-600 
                 mg/kg feed 
               
               
                 chloride 
               
               
                   
               
            
           
         
       
     
     Other Ingredients 
     The composition of the invention may further comprise colouring agents, stabilisers, growth improving additives and aroma compounds/flavourings, polyunsaturated fatty acids (PUFAs); reactive oxygen generating species, antioxidants, anti-microbial peptides, anti-fungal polypeptides and mycotoxin management compounds. 
     Examples of colouring agents are carotenoids such as beta-carotene, astaxanthin, and lutein. 
     Examples of aroma compounds/flavourings are creosol, anethol, deca-, undeca- and/or dodeca-lactones, ionones, irone, gingerol, piperidine, propylidene phatalide, butylidene phatalide, capsaicin and tannin. 
     Examples of antimicrobial peptides (AMP&#39;s) are CAP18, Leucocin A, Tritrpticin, Protegrin-1, Thanatin, Defensin, Lactoferrin, Lactoferricin, and Ovispirin such as Novispirin (Robert Lehrer, 2000), Plectasins, and Statins, including the compounds and polypeptides disclosed in WO 03/044049 and WO 03/048148, as well as variants or fragments of the above that retain antimicrobial activity. 
     Examples of antifungal polypeptides (AFP&#39;s) are the  Aspergillus giganteus , and  Aspergillus niger  peptides, as well as variants and fragments thereof which retain antifungal activity, as disclosed in WO 94/01459 and WO 02/090384. 
     Examples of polyunsaturated fatty acids are C18, C20 and C22 polyunsaturated fatty acids, such as arachidonic acid, docosohexaenoic acid, eicosapentaenoic acid and gamma-linoleic acid. 
     Examples of reactive oxygen generating species are chemicals such as perborate, persulphate, or percarbonate; and enzymes such as an oxidase, an oxygenase or a syntethase. 
     Antioxidants can be used to limit the number of reactive oxygen species which can be generated such that the level of reactive oxygen species is in balance with antioxidants. Examples of antioxidants are Alkosel R397 and Melofeed (Lallamand). 
     Mycotoxins, such as deoxynivalenol, aflatoxin, zearalenone and fumonisin can be found in animal feed and can result in negative animal performance or illness. Compounds which can manage the levels of mycotoxin, such as via deactivation of the mycotoxin or via binding of the mycotoxin, can be added to the feed to ameliorate these negative effects. Examples of mycotoxin management compounds are Vitafix®, Vitafix Ultra (Nuscience), Mycofix®, Mycofix® Secure, FUMzyme®, Biomin® BBSH, Biomin® MTV (Biomin), Mold-Nil®, Toxy-Nil® and Unike® Plus (Nutriad). 
     Plants 
     The present invention also relates to isolated plants, e.g., a transgenic plant, plant part, or plant cell, comprising a polynucleotide of the present invention so as to express and produce a polypeptide or domain in recoverable quantities. The polypeptide or domain may be recovered from the plant or plant part. Alternatively, the plant or plant part containing the polypeptide or domain may be used as such for improving the quality of a food or feed, e.g., improving nutritional value, palatability, and rheological properties, or to destroy an antinutritive factor. 
     The transgenic plant can be dicotyledonous (a dicot) or monocotyledonous (a monocot). Examples of monocot plants are grasses, such as meadow grass (blue grass,  Poa ), forage grass such as  Festuca, Lolium , temperate grass, such as  Agrostis , and cereals, e.g., wheat, oats, rye, barley, rice,  Sorghum , and maize (corn). 
     Examples of dicot plants are tobacco, legumes, such as lupins, potato, sugar beet, pea, bean and soybean, and cruciferous plants (family Brassicaceae), such as cauliflower, rape seed, and the closely related model organism  Arabidopsis thaliana.    
     Examples of plant parts are stem, callus, leaves, root, fruits, seeds, and tubers as well as the individual tissues comprising these parts, e.g., epidermis, mesophyll, parenchyme, vascular tissues, meristems. 
     Plant cells and specific plant cell compartments, such as chloroplasts, apoplasts, mitochondria, vacuoles, peroxisomes and cytoplasm are also considered to be a plant part. 
     Also included within the scope of the present invention are the progeny of such plants, plant parts, and plant cells. 
     The transgenic plant or plant cell expressing the polypeptide or domain may be constructed in accordance with methods known in the art. 
     The present invention also relates to methods of producing a polypeptide or domain of the present invention comprising (a) cultivating a transgenic plant or a plant cell comprising a polynucleotide encoding the polypeptide or domain under conditions conducive for production of the polypeptide or domain; and (b) recovering the polypeptide or domain. 
     Uses 
     The present invention is also directed to methods for using the xylanase variants, or compositions thereof, for, e.g., animal feed, processes for producing a fermentation product, in baking or in brewing. The present invention is also directed to processes for using the xylanase variants, or compositions thereof, such as, e.g., those described below. 
     Use in Animal Feed 
     The present invention is also directed to methods for using the xylanase variants in animal feed. 
     The term animal includes all animals. Examples of animals are non-ruminants, and ruminants. Ruminant animals include, for example, animals such as sheep, goats, and cattle, e.g., beef cattle, cows, and young calves. In a particular embodiment, the animal is a non-ruminant animal. Non-ruminant animals include mono-gastric animals, e.g., pigs or swine (including, but not limited to, piglets, growing pigs, and sows); poultry such as turkeys, ducks and chicken (including but not limited to broiler chicks, layers); horses (including but not limited to hotbloods, coldbloods and warm bloods), young calves; and fish (including but not limited to salmon, trout, tilapia, catfish and carps; and crustaceans (including but not limited to shrimps and prawns). 
     In the use according to the invention the xylanase variants can be fed to the animal before, after, or simultaneously with the diet. The latter is preferred. 
     In a particular embodiment, the form in which the xylanase variant is added to the feed, or animal feed additive, is well-defined. Well-defined means that the xylanase and/or arabinofuranosidase preparation is at least 50% pure as determined by Size-exclusion chromatography (see Example 12 of WO 01/58275). In other particular embodiments the xylanase and/or arabinofuranosidase preparation is at least 60, 70, 80, 85, 88, 90, 92, 94, or at least 95% pure as determined by this method. 
     A well-defined xylanase preparation is advantageous. For instance, it is much easier to dose correctly to the feed a xylanase that is essentially free from interfering or contaminating other xylanases. The term dose correctly refers in particular to the objective of obtaining consistent and constant results, and the capability of optimizing dosage based upon the desired effect. 
     For the use in animal feed, however, the xylanase need not be that pure; it may, e.g., include other enzymes, in which case it could be termed a xylanase preparation. 
     The xylanase preparation can be (a) added directly to the feed, or (b) it can be used in the production of one or more intermediate compositions such as feed additives or premixes that is subsequently added to the feed (or used in a treatment process). The degree of purity described above refers to the purity of the original xylanase preparation, whether used according to (a) or (b) above. 
     Methods for Improving the Nutritional Value of Animal Feed 
     The present invention further relates to a method for improving the nutritional value of an animal feed comprising plant based material from the sub-family Panicoideae, comprising adding to the feed a xylanase variant. 
     The term improving the nutritional value of an animal feed means improving the availability of nutrients in the feed. The nutritional values refers in particular to improving the solubilization and degradation of the arabinoxylan-containing fraction (e.g., such as hemicellulose) of the feed, thereby leading to increased release of nutrients from cells in the endosperm that have cell walls composed of highly recalcitrant hemicellulose. Consequently, an increased release of arabinoxylan oligomers indicates a disruption of the cell walls and as a result the nutritional value of the feed is improved resulting in increased growth rate and/or weight gain and/or feed conversion (i.e., the weight of ingested feed relative to weight gain). In addition the arabinoxylan oligomer release may result in improved utilization of these components per se either directly or by bacterial fermentation in the hind gut thereby resulting in a production of short chain fatty acids that may be readily absorbed in the hind and utilised in the energy metabolism. 
     Methods of Improving Animal Performance 
     The invention further relates to a method of improving one or more performance parameters of an animal, comprising administering to one or more animals a xylanase variant and plant based material from the sub-family Panicoideae. 
     The plant based material from the sub-family Panicoideae may be administered together or separately with the xylanase variant. The xylanase variant may be administered in a composition or in an animal feed additive. In an embodiment, the plant based material from the sub-family Panicoideae is maize, corn,  Sorghum , switchgrass, millet, pearl millet, foxtail millet or in a processed form such as milled corn, milled maize, defatted maize, defatted destarched maize, milled  Sorghum , milled switchgrass, milled millet, milled foxtail millet, milled pearl millet, or any combination thereof. In a further embodiment, the the plant based material from the sub-family Panicoideae is from the seed fraction (such as endosperm and/or husk) of the plant. 
     In an embodiment, the improvement in the performance of an animal is an increase in body weight gain. In another embodiment, the improvement is an improved feed conversion ratio. In a further embodiment, the improvement is an increased feed efficiency. In a further embodiment, the improvement is an increase in body weight gain and/or an improved feed conversion ratio and/or an increased feed efficiency. 
     Methods of Solubilizing Xylan from Plant Based Materials 
     The invention further relates to methods of solubilizing xylan from a plant based material, e.g., by degrading the xylose backbone of sterically hindered arabinoxylan found in plant based material from the sub-family Panicoideae, thereby solubilizing increased amounts of arabinoxylan which is measured as arabinose and xylose. Increased degradation, and thereby increased arabinose and xylose release, can result in advantages for many industries which use plant based material from the sub-family Panicoideae. 
     The amount of starch present in untreated plant material makes it difficult to detect significant solubilization of arabinoxylan. Thus model substrates, wherein the starch and fat present in the plant material is removed without effecting the degree of substitution, can be used to aid the determination of improved enzyme combinations over known prior art combinations. One model substrate is defatted destarched maize (DFDSM) and can be prepared as described in the Examples. It is important that the model substrate is not prepared using strongly acidic or basic conditions or high temperatures, since such conditions can remove the side chain carbohydrate molecules and/or ester groups present on the xylan backbone. If these side chain groups are removed, then the complexity and degree of substitution will be reduced resulting in an arabinoxylan material which is easy to degrade by known solutions. It is for this reason that heat, acid and/or base pre-treatment is used in biomass conversion. 
     In order to measure the solubilization of the arabinoxylan, the soluble arabinoxylan is hydrolyzed with acid resulting in xylose and arabinose being released into the supernatant. This xylose and arabinose is then detected using, e.g., the HPLC method as described herein. The higher the degree of solubilization of the arabinoxylan, the higher the amount of xylose and arabinose released upon acid hydrolysis. It is believed that increasing the solubilization of the arabinoxylan opens up the cell walls that can result in the nutrients, such as starch and protein, which are trapped inside being released. The release of starch and other nutrients can result in improved animal performance and/or improve the nutritional value of an animal feed. 
     In an embodiment, the percentage solubilized xylan is at least 4% when the method is performed under the reaction conditions 20 μg xylanase variant per gram defatted destarched maize (DFDSM) and incubation at 40° C., pH 5 for 2.5 hours. 
     In another embodiment, the xylanase variant solubilizes at least 7% solubilized xylan from plant based material from the sub-family Panicoideae when the method is performed under the reaction conditions 20 μg xylanase variant per gram defatted destarched maize (DFDSM) and incubation at 40° C., pH 5 for 2.5 hours. 
     In a more preferred embodiment, the xylanase variant solubilizes at least 9.5% solubilized xylan from plant based material from the sub-family Panicoideae when the method is performed under the reaction conditions 20 μg xylanase variant per gram defatted destarched maize (DFDSM) and incubation at 40° C., pH 5 for 2.5 hours. 
     Methods of Releasing Starch 
     The invention further relates to a method of releasing starch from plant based material, comprising treating plant based material from the sub-family Panicoideae with a xylanase variant. 
     Processes for Producing Fermentation Products 
     Processes for Producing Fermentation Products from Un-Gelatinized Starch-Containing Material 
     The invention also relates to processes for producing fermentation products from starch-containing material without gelatinization (i.e., without cooking) of the starch-containing material (often referred to as a “raw starch hydrolysis” process). The fermentation product, such as ethanol, can be produced without liquefying the aqueous slurry containing the starch-containing material and water. In one embodiment a process of the invention includes saccharifying (e.g., milled) starch-containing material, e.g., granular starch, below the initial gelatinization temperature, preferably in the presence of alpha-amylase and/or carbohydrate-source generating enzyme(s) to produce sugars that can be fermented into the fermentation product by a suitable fermenting organism. In this embodiment the desired fermentation product, e.g., ethanol, is produced from un-gelatinized (i.e., uncooked), preferably milled, cereal grains, such as corn. 
     Accordingly, in one aspect the invention relates to processes for producing a fermentation product from starch-containing material comprising simultaneously saccharifying and fermenting starch-containing material using a carbohydrate-source generating enzymes and a fermenting organism at a temperature below the initial gelatinization temperature of said starch-containing material in the presence of a variant protease of the invention. Saccharification and fermentation may also be separate. Thus in another aspect the invention relates to processes of producing fermentation products, comprising the following steps: 
     (i) saccharifying a starch-containing material at a temperature below the initial gelatinization temperature using a carbohydrate-source generating enzyme, e.g., a glucoamylase; and 
     (ii) fermenting using a fermentation organism; 
     wherein step (i) is carried out using at least a glucoamylase and a xylanase variant of the invention. 
     In one embodiment, an alpha amylase, in particular a fungal alpha-amylase, is also added in step (i). Steps (i) and (ii) may be performed simultaneously. 
     Processes for Producing Fermentation Products from Gelatinized Starch-Containing Material 
     In this aspect, the invention relates to processes for producing fermentation products, especially ethanol, from starch-containing material, which process includes a liquefaction step and sequentially or simultaneously performed saccharification and fermentation steps. Consequently, the invention relates to a process for producing a fermentation product from starch-containing material comprising the steps of: 
     (a) liquefying starch-containing material in the presence of an alpha-amylase; 
     (b) saccharifying the liquefied material obtained in step (a) using a carbohydrate-source generating enzyme; 
     (c) fermenting using a fermenting organism; 
     wherein a xylanase variant of the invention is present during step a), b) and/or c). 
     The slurry is heated to above the gelatinization temperature and an alpha-amylase variant may be added to initiate liquefaction (thinning). The slurry may in an embodiment be jet-cooked to further gelatinize the slurry before being subjected to alpha-amylase in step (a). Liquefaction may in an embodiment be carried out as a three-step hot slurry process. The slurry is heated to between 60-95° C., preferably between 70-90° C., such as preferably between 80-85° C. at a pH of 4-6, in particular at a pH of 4.5-5.5, and alpha-amylase variant, optionally together with a pullulanase and/or protease, preferably metalloprotease, are added to initiate liquefaction (thinning). The liquefaction process is usually carried out at a pH of 4-6, in particular at a pH from 4.5 to 5.5. Saccharification step (b) may be carried out using conditions well known in the art. For instance, a full saccharification process may last up to from about 24 to about 72 hours, however, it is common only to do a pre-saccharification of typically 40-90 minutes at a temperature between 30-65° C., typically about 60° C., followed by complete saccharification during fermentation in a simultaneous saccharification and fermentation process (SSF process). Saccharification is typically carried out at a temperature from 20-75° C., in particular 40-70° C., typically around 60° C., and at a pH between 4 and 5, normally at about pH 4.5. The most widely used process to produce a fermentation product, especially ethanol, is a simultaneous saccharification and fermentation (SSF) process, in which there is no holding stage for the saccharification, meaning that a fermenting organism, such as yeast, and enzyme(s), may be added together. SSF may typically be carried out at a temperature from 25° C. to 40° C., such as from 28° C. to 35° C., such as from 30° C. to 34° C., preferably around about 32° C. In an embodiment fermentation is ongoing for 6 to 120 hours, in particular 24 to 96 hours. 
     Processes for Reducing Viscosity of a Post-Fermentation Process Stream 
     In this aspect, the invention relates to processes for reducing the viscosity of a post-fermentation process stream. As used herein, the phrase “post-fermentation process stream” refers to contents within and flowing between unit operations occurring downstream from fermentation in a fermentation product production process, such as especially ethanol production. Consequently, the invention relates to a process for reducing the viscosity of a post-fermentation process stream comprising the steps of: 
     (a) producing a fermentation product from a starch-containing material wherein a saccharified starch-containing material is fermented in the presence of a fermenting organism to produce a fermented mash; 
     (b) recovering a fermentation product from the fermented mash to form a whole stillage stream; 
     (c) separating the whole stillage stream into a thin stillage stream and wet cake; 
     (d) optionally evaporating the thin stillage stream to form at least a syrup stream; 
     (e) adding a xylanase variant of the invention to one or more of the saccharified starch-containing material or fermented mash in step (a), the whole stillage stream formed in step (b), the thin stillage stream formed in step (c), and/or the syrup stream optionally formed in step (d), thereby reducing the viscosity of the fermented mash, the whole stillage stream, the thin stillage stream, and/or optionally the syrup stream. 
     In an embodiment, producing the fermentation product in step (a) includes a pre-saccharification step, and a xylanase variant of the invention is added to or present during the pre-saccharification step. In an embodiment, producing the fermentation product in step (a) includes a saccharification step and/or a simultaneous saccharification and fermentation step, and a xylanase variant of the invention is added to or present during the saccharification step and/or the simultaneous saccharification and fermentation step. In an embodiment, a xylanase variant of the invention is added to the fermented mash in step (a). 
     In an embodiment, the process for reducing viscosity further includes adding an additional enzyme to one or more of the saccharified starch-containing material or fermented mash in step (a), the whole stillage stream formed in step (b), the thin stillage stream formed in step (c), and/or the syrup stream optionally formed in step (d), wherein the additional enzyme is selected from the group consisting of an amylase, a xyloglucanase, a cellulase, a pectinase, an endoglucanase, a beta-glucosidase, and mixtures thereof. 
     Starch-Containing Materials 
     Any suitable starch-containing starting material may be used in a process of the present invention. The starting material is generally selected based on the desired fermentation product. Examples of starch-containing starting materials, suitable for use in the processes of the present invention, include barley, beans, cassava, cereals, corn, milo, peas, potatoes, rice, rye, sago,  Sorghum , sweet potatoes, tapioca, wheat, and whole grains, or any mixture thereof. The starch-containing material may also be a waxy or non-waxy type of corn and barley. In a preferred embodiment the starch-containing material is corn. In a preferred embodiment the starch-containing material is wheat. 
     Fermentation Products 
     The term “fermentation product” means a product produced by a method or process including fermenting using a fermenting organism. Fermentation products include alcohols (e.g., ethanol, methanol, butanol); organic acids (e.g., citric acid, acetic acid, itaconic acid, lactic acid, succinic acid, gluconic acid); ketones (e.g., acetone); amino acids (e.g., glutamic acid); gases (e.g., H 2  and CO 2 ); antibiotics (e.g., penicillin and tetracycline); enzymes; vitamins (e.g., riboflavin, B 12 , beta-carotene); and hormones. In a preferred embodiment the fermentation product is ethanol, e.g., fuel ethanol; drinking ethanol, i.e., potable neutral spirits; or industrial ethanol or products used in the consumable alcohol industry (e.g., beer and wine), dairy industry (e.g., fermented dairy products), leather industry and tobacco industry. Preferred beer types comprise ales, stouts, porters, lagers, bitters, malt liquors, happoushu, high-alcohol beer, low-alcohol beer, low-calorie beer or light beer. In an embodiment the fermentation product is ethanol. 
     Fermenting Organisms 
     The term “fermenting organism” refers to any organism, including bacterial and fungal organisms, such as yeast and filamentous fungi, suitable for producing a desired fermentation product. Suitable fermenting organisms are able to ferment, i.e., convert, fermentable sugars, such as arabinose, fructose, glucose, maltose, mannose, or xylose, directly or indirectly into the desired fermentation product. 
     Examples of fermenting organisms include fungal organisms such as yeast. Preferred yeast include strains of  Saccharomyces , in particular  Saccharomyces cerevisiae  or  Saccharomyces uvarum ; strains of  Pichia , in particular  Pichia stipitis  such as  Pichia stipitis  CBS 5773 or  Pichia pastoris ; strains of  Candida , in particular  Candida arabinofermentans, Candida boidinii, Candida diddensii, Candida shehatae, Candida sonorensis, Candida tropicalis , or  Candida utilis . Other fermenting organisms include strains of  Hansenula , in particular  Hansenula anomala  or  Hansenula polymorpha ; strains of  Kluyveromyces , in particular  Kluyveromyces fragilis  or  Kluyveromyces marxianus ; and strains of  Schizosaccharomyces , in particular  Schizosaccharomyces pombe.    
     In an embodiment, the fermenting organism is a C6 sugar fermenting organism, such as a strain of, e.g.,  Saccharomyces cerevisiae.    
     In an embodiment, the fermenting organism is a C5 sugar fermenting organism, such as a strain of, e.g.,  Saccharomyces cerevisiae.    
     Fermentation 
     The fermentation conditions are determined based on, e.g., the kind of plant material, the available fermentable sugars, the fermenting organism(s) and/or the desired fermentation product. One skilled in the art can easily determine suitable fermentation conditions. The fermentation may be carried out at conventionally used conditions. Preferred fermentation processes are anaerobic processes. 
     For example, fermentations may be carried out at temperatures as high as 75° C., e.g., between 40-70° C., such as between 50-60° C. However, bacteria with a significantly lower temperature optimum down to around room temperature (around 20° C.) are also known. Examples of suitable fermenting organisms can be found in the “Fermenting Organisms” section above. 
     For ethanol production using yeast, the fermentation may go on for 24 to 96 hours, in particular for 35 to 60 hours. In an embodiment the fermentation is carried out at a temperature between 20 to 40° C., preferably 26 to 34° C., in particular around 32° C. In an embodiment the pH is from pH 3 to 6, preferably around pH 4 to 5. 
     Recovery of Fermentation Products 
     Subsequent to fermentation or SSF, the fermentation product may be separated from the fermentation medium. The slurry may be distilled to extract the desired fermentation product (e.g., ethanol). Alternatively the desired fermentation product may be extracted from the fermentation medium by micro or membrane filtration techniques. The fermentation product may also be recovered by stripping or other method well known in the art. Typically, the fermentation product, e.g., ethanol, with a purity of up to, e.g., about 96 vol. percent ethanol is obtained. 
     Thus, in one embodiment, the method of the invention further comprises distillation to obtain the fermentation product, e.g., ethanol. The fermentation and the distillation may be carried out simultaneously and/or separately/sequentially; optionally followed by one or more process steps for further refinement of the fermentation product. 
     Following the completion of the distillation process, the material remaining is considered the whole stillage. As used herein, the term “whole stillage” includes the material that remains at the end of the distillation process after recovery of the fermentation product, e.g., ethanol. The fermentation product can optionally be recovered by any method known in the art. 
     In an embodiment, a xylanase of the invention is added to the whole stillage stream. 
     Separating (Dewatering) Whole Stillage into Thin Stillage and Wet Cake 
     In one embodiment, the whole stillage is separated or partitioned into a solid and liquid phase by one or more methods for separating the thin stillage from the wet cake. 
     Separating whole stillage into thin stillage and wet cake in order to remove a significant portion of the liquid/water, may be done using any suitable separation technique, including centrifugation, pressing and filtration. In a preferred embodiment, the separation/dewatering is carried out by centrifugation. Preferred centrifuges in industry are decanter type centrifuges, preferably high speed decanter type centrifuges. An example of a suitable centrifuge is the NX 400 steep cone series from Alfa Laval which is a high-performance decanter. In another preferred embodiment, the separation is carried out using other conventional separation equipment such as a plate/frame filter presses, belt filter presses, screw presses, gravity thickeners and deckers, or similar equipment. 
     In an embodiment, a xylanase variant of the invention is added to the thin stillage stream. 
     Processing of Thin Stillage 
     Thin stillage is the term used for the supernatant of the centrifugation of the whole stillage. Typically, the thin stillage contains 4-6 percent dry solids (DS) (mainly proteins, soluble fiber, fine fibers, and cell wall components) and has a temperature of about 60-90 degrees centigrade. The thin stillage stream may be condensed by evaporation to provide two process streams including: (i) an evaporator condensate stream comprising condensed water removed from the thin stillage during evaporation, and (ii) a syrup stream, comprising a more concentrated stream of the non-volatile dissolved and non-dissolved solids, such as non-fermentable sugars and oil, remaining present from the thin stillage as the result of removing the evaporated water. Optionally, oil can be removed from the thin stillage or can be removed as an intermediate step to the evaporation process, which is typically carried out using a series of several evaporation stages. Syrup and/or de-oiled syrup may be introduced into a dryer together with the wet grains (from the whole stillage separation step) to provide a product referred to as distillers dried grain with solubles, which also can be used as animal feed. 
     In an embodiment, syrup and/or de-oiled syrup is sprayed into one or more dryers to combine the syrup and/or de-oiled syrup with the whole stillage to produce distillers dried grain with solubles. 
     In an embodiment, the step of forming the syrup stream is performed and the xylanase variant of the invention is added to the syrup stream formed. 
     Between 5-90 vol-%, such as between 10-80%, such as between 15-70%, such as between 20-60% of thin stillage (e.g., optionally hydrolyzed) may be recycled (as backset) to step (a). The recycled thin stillage (i.e., backset) may constitute from about 1-70 vol.-%, preferably 15-60% vol.-%, especially from about 30 to 50 vol.-% of the slurry formed in step (a). 
     In an embodiment, the process further comprises recycling at least a portion of the thin stillage stream treated with a xylanase variant of the invention to the slurry, optionally after oil has been extracted from the thin stillage stream. 
     Drying of Wet Cake and Producing Distillers Dried Grains and Distillers Dried Grains with Solubles 
     After the wet cake, containing about 25-40 wt-%, preferably 30-38 wt-% dry solids, has been separated from the thin stillage (e.g., dewatered) it may be dried in a drum dryer, spray dryer, ring drier, fluid bed drier or the like in order to produce “Distillers Dried Grains” (DDG). DDG is a valuable feed ingredient for animals, such as livestock, poultry and fish. It is preferred to provide DDG with a content of less than about 10-12 wt.-% moisture to avoid mold and microbial breakdown and increase the shelf life. Further, high moisture content also makes it more expensive to transport DDG. The wet cake is preferably dried under conditions that do not denature proteins in the wet cake. The wet cake may be blended with syrup separated from the thin stillage and dried into DDG with Solubles (DDGS). Partially dried intermediate products, such as are sometimes referred to as modified wet distillers grains, may be produced by partially drying wet cake, optionally with the addition of syrup before, during or after the drying process. 
     Use in Viscosity Reduction 
     In this aspect, the invention relates to the use of a xylanase variant of the invention for reducing the viscosity of a post-fermentation process stream. WO/0238786 (incorporated herein by reference) describes using xylanases, including in mixtures with an alpha-amylase, xyloglucanase, cellulase, and pectinase, for reducing viscosity of fermented mash and post-fermentation process streams. Similarly, US 2015/0176034 (incorporated herein by reference) describes using xylanases, beta-glucosidases, arabinofuranosidases, and endoglucanases, amongst others (see Table 1) for viscosity reduction. Accordingly, without wishing to be bound by theory, it is believed that the xylanase variants of the invention can be used to reduce viscosity of fermented mash and post-fermentation process streams. Consequently, the invention relates to the use of a xylanase variant of the invention for reducing the viscosity of a post-fermentation process stream. 
     The present invention contemplates reducing the viscosity of any post-fermentation process stream. In an embodiment, the post-fermentation process stream is selected from the group consisting of a whole stillage stream, a thin stillage stream, and a syrup stream. In an embodiment, the post-fermentation process stream is whole stillage. In an embodiment, the post-fermentation process stream is thin stillage. In an embodiment, the post-fermentation process stream is syrup. 
     In an embodiment, an additional viscosity reducing enzyme is used in combination with a xylanase variant of the invention, wherein the additional enzyme is selected from the group consisting of an amylase, a xyloglucanase, a cellulase, a pectinase, an endoglucanase, a beta-glucosidase, and mixtures thereof. 
     Use in Baking 
     The invention discloses a method for preparing a dough which comprises incorporating into the dough a xylanase variant of the invention. 
     The phrase “incorporating into the dough” is defined herein as adding the xylanase variant to the dough, to any ingredient from which the dough is to be made, and/or to any mixture of dough ingredients from which the dough is to be made. 
     In other words, the xylanase variant may be added in any step of the dough preparation and may be added in one, two, or more steps. The xylanase variant may be added to the ingredients of dough that is kneaded and baked, using methods well known in the art. 
     The term “dough” is defined herein as a mixture of flour and other ingredients firm enough to knead or roll. 
     The dough may comprise flour derived from any cereal grain, including wheat, barley, rye, oat, corn,  Sorghum , rice, millet, and any mixtures thereof. 
     The dough may also comprise other conventional dough ingredients, e.g., proteins, such as milk powder, gluten, and soy; eggs (either whole eggs, egg yolks, or egg whites); an oxidant such as ascorbic acid, potassium bromate, potassium iodate, azodicarbonamide (ADA) or ammonium persulfate; an amino acid such as L-cysteine; a starch; and/or a salt such as sodium chloride, calcium acetate, sodium sulfate or calcium sulfate. The starch may be wheat starch, corn starch, maize starch, tapioca starch, cassava starch, potato starch; and/or a sugar such as sucrose, cane sugar, lactose, or high fructose corn syrup. 
     The dough may comprise fat (triglyceride) such as granulated fat or shortening. 
     The dough may be fresh, frozen, or par-baked (pre-baked). 
     The dough is normally leavened dough or dough to be subjected to leavening. The dough may be leavened in various ways, such as by adding chemical leavening agents, e.g., sodium bicarbonate or by adding a leaven (fermenting dough), but it is preferred to leaven the dough by adding a suitable yeast culture, such as a culture of  Saccharomyces cerevisiae  (baker&#39;s yeast), e.g., a commercially available strain of  S. cerevisiae.    
     Baked Product 
     The present invention also relates to a process of preparing a baked or steamed product from the dough (such as fiber dough), either of a soft or a crisp character and of a white, light or dark type. 
     Examples of baked products are bread typically in the form of loaves or rolls, pan bread, toast bread, pan bread with and without lid, buns, hamburger buns, rolls, baguettes, brown bread, whole meal bread, rich bread, bran bread, flat bread, tortilla, pita, Arabic bread, Indian flat bread, steamed bread, and any variety thereof. 
     Preferred Embodiments of the Invention 
     Preferred embodiments of the invention are described in the set of items below.
     1. A method for obtaining a xylanase variant, comprising
       (a) introducing into a parent xylanase a substitution at one or more positions corresponding to positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 31, 32, 33, 34, 39, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 64, 65, 67, 68, 79, 82, 88, 90, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 127, 128, 129, 131, 135, 143, 145, 146, 159, 160, 165, 168, 176, 179, 181, 188, 191, 194, 195, 196, 197, 205, 209, 212, 217, 218, 221, 224, 231, 235, 237, 238, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 338, 339, 340, 342, 343, 344, 345, 346, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1, wherein the xylanase variant has xylanase activity and has at least 70% sequence identity to SEQ ID NO: 1; and   (b) recovering the xylanase variant.   
       2. The method of item 1, wherein the xylanase variant has improved thermostability relative to the parent.   3. The method of item 1, wherein the xylanase variant has improved thermostability relative to the parent xylanase of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C.   4. The method of item 1, wherein the xylanase variant has improved thermostability relative to SEQ ID NO: 1 of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C.   5. The method of any of items 1 to 4, wherein the xylanase variant has at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NO: 1.   6. The method of any of items 1 to 5, wherein the parent xylanase has at least 70%, e.g., at at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 1.   7. The method of any of items 1 to 6, wherein the parent xylanase is obtained or obtainable from the taxonomic order Bacillales, preferably the taxonomic family Bacillaceae.   8. The method of any of items 1 to 7, wherein the parent xylanase is obtained or obtainable from the taxonomic genus  Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis  or  Paenibacillus pabuli.      9. The method of any of items 1 to 8, wherein the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 1 or is a fragment of SEQ ID NO: 1, wherein the fragment has xylanase activity.   10. The method of any of items 1 to 8, wherein the parent xylanase comprises the amino acid sequence of SEQ ID NO: 1 and an N- and/or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids.   11. The method of any of items 1 to 9, wherein the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position.   12. The method of any of items 1 to 11, wherein the substitution is selected from the group consisting of A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W and Y, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position.   13. The method of any of items 1 to 12, wherein the one or more substitutions is selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, A2L, A2Y, S3W, S3F, S3H, S3L, S3G, S3M, S3T, S3P, D4L, D4C, D4Y, D4Q, D4A, D4K, D4P, V5H, V5G, V5P, T6K, T6Q, T6L, T6N, T6R, T6D, T6F, T6H, V7F, V7S, V7C, V7A, V7W, N8Q, N8R, N8D, N8F, N8W, N8Y, N8S, N8M, N8L, N8V, N8T, N8I, N8A, V9H, V9R, V9M, S10A, S10H, S10L, S10I, S10D, S10K, S10V, A11P, A11I, A11N, A11G, A11Y, A11C, A11S, A11F, A11M, A11D, A11L, A11H, A11W, A11E, A11V, A11R, A11Q, E12G, E12R, E12K, E12T, E12V, E12W, E12C, K13Q, K13H, K13N, K13L, K13S, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, Q14D, V15F, V15L, V15N, V15K, V15H, G18H, G18Y, G18W, G18F, G18C, G18S, G18A, F19H, F19Y, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, L31V, T32N, T32D, A33Q, A33H, A33M, A33Y, A33K, A33E, A33R, A33C, A33N, A34F, A34N, A34C, A34L, A34P, A34S, A34Q, A39S, G43W, G43A, G43N, Q44D, Q44N, Q44R, Q44Y, Q44K, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, N45G, N45P, N45T, N45Y, Q46D, Q46H, Q46C, Q46S, Q46T, Q46N, Q46K, G48L, G48V, G48I, G48Q, G48C, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, S50T, E58P, E58K, E58R, N59C, N59V, N59D, N59K, N59L, N59S, N61W, N61L, N61D, N61E, N61H, N61M, N61Y, N61I, N61T, N61F, N61Q, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, N62Q, Y64F, Y64N, K65I, K65L, V67A, V67S, V67F, V67G, V67K, E68W, E68V, E68I, E68A, E68H, E68N, I79K, I79R, I79V, I79A, A82G, P88M, P88F, P88T, P88W, P88Q, D90R, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A112G, A112T, A112V, A113E, A113Q, A113L, A113D, A113S, Q116E, Q116A, Q116G, N119G, N119S, N119V, N119L, N119C, N119R, D120R, D120A, D120S, D120Y, D120L, D120W, D120T, D120G, T123E, T123Y, T123C, T123H, T123Q, T123K, T123V, T123G, T123R, T123I, K126R, K126A, K126Y, K126L, K126F, K126W, K126E, K126H, K126Q, N127P, N127W, N128H, N128K, G129M, G129Q, G129A, G129F, G129W, N131K, N131R, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, H145W, E146R, E146H, E146Y, E146F, E146W, E146A, E146K, E146G, E146S, M159C, R160I, S165Y, S165M, S165I, A168I, A168R, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N181A, N181T, N188M, N188E, N188L, Q191I, Q191K, Q191V, Q191R, Q191L, Q191M, A194H, A194R, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, G205C, G205Q, S209N, S209C, S209W, P212A, P212K, P212Q, P212R, P212E, P212S, P212N, K217Q, K217M, Q218H, Q218I, A221R, A221K, A221H, A221Q, A221C, A221N, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, N238G, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, D280N, D280R, T282M, T282H, T282R, T282C, T282V, T282L, T282E, T282F, K295W, K295T, K295I, K295V, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, R298P, R298Y, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, P299G, P299S, G300A, G300R, V302I, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, V302F, D305W, D305F, D305I, D305M, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307S, T307H, T307E, T307Y, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, N313L, N313C, N313G, N313F, D322F, D322G, D322L, N323A, N323C, N323Q, N323L, N323G, N323R, N323E, N323S, N323Y, N323P, K324S, K324P, S333I, S333R, S333T, N334I, N334A, N334L, T335I, T335A, G336C, G336A, G336E, V337A, V337Q, V337D, V337M, V337E, V337G, N338H, Q339I, Q339T, Q339A, N340S, N340A, N340C, V342A, V342L, V342I, V342R, V342D, L343C, L343Q, L343I, L343A, L343P, L343S, L343D, L343Y, L343F, L343K, L343H, L343E, L343N, Q344I, Q344R, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, N345I, N345V, N345P, G346H, S347R, S347H, S347I, S347A, S347G, S347K, S347Y, S347W, S347T, S347L, S347F, S349R, S349C, S349A, S349V, S349I, S349F, S349Y, S349T, S349M, S349D, N350K, N350A, W354L, S357V, S357Q, S359H, S359Q, S359F, S359R, S359I, S359G, S359Y, S359A, S359P, S359N, S359W, S359E, S360R, S360G, Q363V, Q363R, Q363A, Q363G, Q363H, Q363L, Q363N, Q363F, P364Q, P364H, P364W, P364I, P364L, T366S, T366N, T366W, T366Q, T366C, T366V, T366A, T366S, T366L, T366K, T366R, T366G, T366I, T366Q, N367Y, N367P, N367L, N367A, N367F, N367Q, N367W, N367D, N367E, L368D, L368H, S371F, S371W, S371V, S371E, S371R, S371H, S371Q, S371D, S371I, N373D, N373I, N373E, N373W, N373Y, N373A, N373H, N373Q, H374E, H374F, H374D, H374T, H374S, H374I, H374L, H374W, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, W376Y, W376L, W376E, W376G, W376F, W376R, A377I, A377V, A377M, H378A, H378T, H378I, H378R, H378C, H378M, H378Q, H378N, H378G, H378L, H378V, H378S, H378Y, H378K, H378D, H378P, H378E, H378F, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, P380K, P380H, T385F, T385M, T385R, V388E, V388D, V388Y, V388K, V388H, V388L, V388Q, N390R, N390M, N390P, R391C, R391M, R391G, R391P, R391H and R391V.   14. The method of any of items 1 to 13, wherein the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions.   15. A xylanase variant produced by the method of any of items 1 to 14.   16. A xylanase variant having xylanase activity, wherein the variant has at least 70% sequence identity to SEQ ID NO: 1 and comprises a substitution at one or more positions corresponding to positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 31, 32, 33, 34, 39, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 64, 65, 67, 68, 79, 82, 88, 90, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 127, 128, 129, 131, 135, 143, 145, 146, 159, 160, 165, 168, 176, 179, 181, 188, 191, 194, 195, 196, 197, 205, 209, 212, 217, 218, 221, 224, 231, 235, 237, 238, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 338, 339, 340, 342, 343, 344, 345, 346, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1.   17. The xylanase variant of item 16, wherein the substitution is introduced into a parent xylanase by replacing the original amino acid residue with a different amino acid residue.   18. The xylanase variant of any of items 16 to 17, wherein the variant has improved thermostability compared to the parent xylanase.   19. The xylanase variant of any of items 16 to 18, wherein the xylanase variant has improved thermostability relative to the parent xylanase of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C.   20. The xylanase variant of any of items 16 to 18, wherein the xylanase variant has improved thermostability relative to SEQ ID NO: 1 of at least 0.1° C., at least 0.5° C., at least 1.0° C., at least 1.5° C., at least 2.0° C., at least 2.5° C., at least 3.0° C., at least 3.5° C. or at least 4.0° C.   21. The xylanase variant of any of items 16 to 20, wherein the xylanase variant has at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NO: 1.   22. The xylanase variant of any of items 16 to 21, wherein the parent xylanase has at least 70%, e.g., at at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 1.   23. The xylanase variant of any of items 16 to 22, wherein the parent xylanase is obtained or obtainable from the taxonomic order Bacillales, preferably the taxonomic family Bacillaceae.   24. The xylanase variant of any of items 16 to 23, wherein the parent xylanase is obtained or obtainable from the taxonomic genus  Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis  or  Paenibacillus pabuli.      25. The xylanase variant of any of items 16 to 24, wherein the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 1 or is a fragment of SEQ ID NO: 1, wherein the fragment has xylanase activity.   26. The xylanase variant of any of items 16 to 25, wherein the parent xylanase comprises the amino acid sequence of SEQ ID NO: 1 and an N- and/or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids.   27. The xylanase variant of any of items 16 to 26, wherein the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position.   28. The xylanase variant of any of items 16 to 27, wherein the substitution is selected from the group consisting of A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W and Y, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position.   29. The xylanase variant of any of items 16 to 28, wherein the one or more substitutions is selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, A2L, A2Y, S3W, S3F, S3H, S3L, S3G, S3M, S3T, S3P, D4L, D4C, D4Y, D4Q, D4A, D4K, D4P, V5H, V5G, V5P, T6K, T6Q, T6L, T6N, T6R, T6D, T6F, T6H, V7F, V7S, V7C, V7A, V7W, N8Q, N8R, N8D, N8F, N8W, N8Y, N8S, N8M, N8L, N8V, N8T, N8I, N8A, V9H, V9R, V9M, S10A, S10H, S10L, S10I, S10D, S10K, S10V, A11P, A11I, A11N, A11G, A11Y, A11C, A11S, A11F, A11M, A11D, A11L, A11H, A11W, A11E, A11V, A11R, A11Q, E12G, E12R, E12K, E12T, E12V, E12W, E12C, K13Q, K13H, K13N, K13L, K13S, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, Q14D, V15F, V15L, V15N, V15K, V15H, G18H, G18Y, G18W, G18F, G18C, G18S, G18A, F19H, F19Y, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, L31V, T32N, T32D, A33Q, A33H, A33M, A33Y, A33K, A33E, A33R, A33C, A33N, A34F, A34N, A34C, A34L, A34P, A34S, A34Q, A39S, G43W, G43A, G43N, Q44D, Q44N, Q44R, Q44Y, Q44K, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, N45G, N45P, N45T, N45Y, Q46D, Q46H, Q46C, Q46S, Q46T, Q46N, Q46K, G48L, G48V, G48I, G48Q, G48C, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, S50T, E58P, E58K, E58R, N59C, N59V, N59D, N59K, N59L, N59S, N61W, N61L, N61D, N61E, N61H, N61M, N61Y, N61I, N61T, N61F, N61Q, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, N62Q, Y64F, Y64N, K65I, K65L, V67A, V67S, V67F, V67G, V67K, E68W, E68V, E68I, E68A, E68H, E68N, I79K, I79R, I79V, I79A, A82G, P88M, P88F, P88T, P88W, P88Q, D90R, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A112G, A112T, A112V, A113E, A113Q, A113L, A113D, A113S, Q116E, Q116A, Q116G, N119G, N119S, N119V, N119L, N119C, N119R, D120R, D120A, D120S, D120Y, D120L, D120W, D120T, D120G, T123E, T123Y, T123C, T123H, T123Q, T123K, T123V, T123G, T123R, T123I, K126R, K126A, K126Y, K126L, K126F, K126W, K126E, K126H, K126Q, N127P, N127W, N128H, N128K, G129M, G129Q, G129A, G129F, G129W, N131K, N131R, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, H145W, E146R, E146H, E146Y, E146F, E146W, E146A, E146K, E146G, E146S, M159C, R160I, S165Y, S165M, S165I, A168I, A168R, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N181A, N181T, N188M, N188E, N188L, Q191I, Q191K, Q191V, Q191R, Q191L, Q191M, A194H, A194R, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, G205C, G205Q, S209N, S209C, S209W, P212A, P212K, P212Q, P212R, P212E, P212S, P212N, K217Q, K217M, Q218H, Q218I, A221R, A221K, A221H, A221Q, A221C, A221N, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, N238G, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, D280N, D280R, T282M, T282H, T282R, T282C, T282V, T282L, T282E, T282F, K295W, K295T, K295I, K295V, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, R298P, R298Y, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, P299G, P299S, G300A, G300R, V302I, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, V302F, D305W, D305F, D305I, D305M, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307S, T307H, T307E, T307Y, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, N313L, N313C, N313G, N313F, D322F, D322G, D322L, N323A, N323C, N323Q, N323L, N323G, N323R, N323E, N323S, N323Y, N323P, K324S, K324P, S333I, S333R, S333T, N334I, N334A, N334L, T335I, T335A, G336C, G336A, G336E, V337A, V337Q, V337D, V337M, V337E, V337G, N338H, Q339I, Q339T, Q339A, N340S, N340A, N340C, V342A, V342L, V342I, V342R, V342D, L343C, L343Q, L343I, L343A, L343P, L343S, L343D, L343Y, L343F, L343K, L343H, L343E, L343N, Q344I, Q344R, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, N345I, N345V, N345P, G346H, S347R, S347H, S347I, S347A, S347G, S347K, S347Y, S347W, S347T, S347L, S347F, S349R, S349C, S349A, S349V, S349I, S349F, S349Y, S349T, S349M, S349D, N350K, N350A, W354L, S357V, S357Q, S359H, S359Q, S359F, S359R, S359I, S359G, S359Y, S359A, S359P, S359N, S359W, S359E, S360R, S360G, Q363V, Q363R, Q363A, Q363G, Q363H, Q363L, Q363N, Q363F, P364Q, P364H, P364W, P364I, P364L, T366S, T366N, T366W, T366Q, T366C, T366V, T366A, T366S, T366L, T366K, T366R, T366G, T366I, T366Q, N367Y, N367P, N367L, N367A, N367F, N367Q, N367W, N367D, N367E, L368D, L368H, S371F, S371W, S371V, S371E, S371R, S371H, S371Q, S371D, S371I, N373D, N373I, N373E, N373W, N373Y, N373A, N373H, N373Q, H374E, H374F, H374D, H374T, H374S, H374I, H374L, H374W, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, W376Y, W376L, W376E, W376G, W376F, W376R, A377I, A377V, A377M, H378A, H378T, H378I, H378R, H378C, H378M, H378Q, H378N, H378G, H378L, H378V, H378S, H378Y, H378K, H378D, H378P, H378E, H378F, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, P380K, P380H, T385F, T385M, T385R, V388E, V388D, V388Y, V388K, V388H, V388L, V388Q, N390R, N390M, N390P, R391C, R391M, R391G, R391P, R391H and R391V.   30. The xylanase variant of any of items 16 to 29, wherein the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions.   31. A composition comprising the xylanase variant of any of items 15 to 30 and a formulating agent.   32. The composition of item 31, wherein the formulating agent comprises one or more of the following compounds: glycerol, ethylene glycol, 1, 2-propylene glycol or 1, 3-propylene glycol, sodium chloride, sodium benzoate, potassium sorbate, sodium sulfate, potassium sulfate, magnesium sulfate, sodium thiosulfate, calcium carbonate, sodium citrate, dextrin, glucose, sucrose, sorbitol, lactose, starch, kaolin, maltodextrin, cyclodextrin, wheat, PVA, acetate, phosphate and cellulose.   33. The composition of any of items 31 to 32, further comprising one or more additional enzymes.   34. The composition of item 33, wherein the one or more additional enzymes is selected from the group consisting of acetyl xylan esterase, alpha-amylase, beta-amylase, arabinofuranosidase, cellobiohydrolases, cellulase, feruloyl esterase, galactanase, alpha-galactosidase, beta-galactosidase, beta-glucanase, beta-glucosidase, lipase, lysophospholipase, lysozyme, mannanase, alpha-mannosidase, beta-mannosidase, phytase, phospholipase A1, phospholipase A2, phospholipase C, phospholipase D, protease, pullulanase, pectinase, pectin lyase, xylanase, beta-xylosidase, or any combination thereof.   35. The composition of any of items 31 to 34, further comprising one or more microbes.   36. The composition of item 35, wherein the one or more microbes is selected from the group consisting of  Bacillus subtilis, Bacillus licheniformis, Bacillus amyloliquefaciens, Bacillus cereus, Bacillus pumilus, Bacillus polymyxa, Bacillus megaterium, Bacillus coagulans, Bacillus circulans, Bifidobacterium bifidum, Bifidobacterium animalis, Bifidobacterium  sp.,  Carnobacterium  sp.,  Clostridium butyricum, Clostridium  sp.,  Enterococcus faecium, Enterococcus  sp.,  Lactobacillus  sp.,  Lactobacillus acidophilus, Lactobacillus farciminus, Lactobacillus rhamnosus, Lactobacillus reuteri, Lactobacillus salivarius, Lactococcus lactis, Lactococcus  sp.,  Leuconostoc  sp.,  Megasphaera elsdenii, Megasphaera  sp.,  Pediococcus acidilactici, Pediococcus  sp.,  Propionibacterium thoenii, Propionibacterium  sp. and  Streptococcus  sp. or any combination thereof.   37. The composition of any of items 31 to 36, further comprising plant based material.   38. The composition of item 37, wherein the plant based material is from the sub-family Panicoideae   39. The composition of item 37, wherein the plant based material from the sub-family Panicoideae is maize, corn,  Sorghum , switchgrass, millet, pearl millet, foxtail millet or in a processed form such as milled corn, milled maize, defatted maize, defatted destarched maize, milled  Sorghum , milled switchgrass, milled millet, milled foxtail millet, milled pearl millet, or any combination thereof.   40. The composition of item 39, wherein the plant based material from the sub-family Panicoideae is from the seed fraction (such as endosperm and/or husk) of the plant.   41. A granule comprising the xylanase variant of any of items 15 to 30 and a formulating agent.   42. The granule of item 41, wherein the one or more formulating agents is selected from the list consisting of glycerol, ethylene glycol, 1, 2-propylene glycol or 1, 3-propylene glycol, sodium chloride, sodium benzoate, potassium sorbate, sodium sulfate, potassium sulfate, magnesium sulfate, sodium thiosulfate, calcium carbonate, sodium citrate, dextrin, glucose, sucrose, sorbitol, lactose, starch, kaolin and cellulose, preferably selected from the list consisting of 1, 2-propylene glycol, 1, 3-propylene glycol, sodium sulfate, dextrin, cellulose, sodium thiosulfate, kaolin and calcium carbonate.   43. The granule of any of items 41 to 42, wherein the granule comprises a core particle and one or more coatings   44. The granule of item 43, wherein the coating comprises salt and/or wax and/or flour.   45. The granule of any of items 41 to 44 further comprising one or more additional enzymes.   46. The granule of item 45, wherein the one or more additional enzymes is selected from the group consisting of acetyl xylan esterase, alpha-amylase, beta-amylase, arabinofuranosidase, cellobiohydrolases, cellulase, feruloyl esterase, galactanase, alpha-galactosidase, beta-galactosidase, beta-glucanase, beta-glucosidase, lipase, lysophospholipase, lysozyme, mannanase, alpha-mannosidase, beta-mannosidase, phytase, phospholipase A1, phospholipase A2, phospholipase C, phospholipase D, protease, pullulanase, pectinase, pectin lyase, xylanase, beta-xylosidase, or any combination thereof.   47. An animal feed additive comprising the xylanase variant of any of items 15 to 30, the composition of any of items 31 to 40 or the granule of any of items 41 to 46 and one or more components selected from the group consisting of:
       one or more vitamins;   one or more minerals;   one or more amino acids;   one or more phytogenics;   one or more prebiotics;   one or more organic acids; and   one or more other ingredients.   
       48. A liquid formulation comprising the xylanase variant of any of items 15 to 30.   49. The liquid formulation of item 48, wherein the xylanase variant is dosed between 0.01% to 25% w/w of liquid formulation, preferably 0.05% to 20% w/w, more preferably 0.2% to 15% w/w, more preferably 0.5% to 15% w/w or most preferably 1.0% to 10% w/w xylanase variant.   50. The liquid formulation of any of items 48 to 49, wherein the formulation further comprises 20% to 80% w/w of polyol.   51. The liquid formulation of item 50, wherein the polyol is selected from the group consisting of glycerol, sorbitol, propylene glycol (MPG), ethylene glycol, diethylene glycol, triethylene glycol, 1, 2-propylene glycol or 1, 3-propylene glycol, dipropylene glycol, polyethylene glycol (PEG) having an average molecular weight below about 600 and polypropylene glycol (PPG) having an average molecular weight below about 600 or any combination thereof.   52. The liquid formulation of any of items 48 to 51, wherein the formulation further comprises 0.01% to 2.0% w/w preservative.   53. The liquid formulation of item 52, wherein the preservative is selected from the group consisting of sodium sorbate, potassium sorbate, sodium benzoate and potassium benzoate or any combination thereof.   54. The liquid formulation of any of items 48 to 53 further comprising one or more components selected from the list consisting of:
       one or more enzymes;   one or more microbes;   one or more vitamins;   one or more minerals;   one or more amino acids;   one or more phytogenics;   one or more prebiotics;   one or more organic acids; and   one or more other ingredients.   
       55. A method of preparing an animal feed, comprising applying the liquid formulation of any of items 48 to 54 onto plant based material.   56. The method of item 55, wherein the liquid formulation is applied via a spray.   57. The method of any of items 55 to 56, wherein the plant based material comprises legumes, cereals, oats, rye, barley, wheat, maize, corn,  Sorghum , switchgrass, millet, pearl millet, foxtail millet, soybean, wild soybean, beans, lupin, tepary bean, scarlet runner bean, slimjim bean, lima bean, French bean, Broad bean (fava bean), chickpea, lentil, peanut, Spanish peanut, canola, rapeseed (oilseed rape), rice, beet, cabbage, sugar beet, spinach,  quinoa , or pea, in a processed form thereof (such as soybean meal, rapeseed meal) or any combination thereof.   58. The method of any of items 55 to 57, wherein the plant based material is in pelleted form.   59. An animal feed comprising the xylanase variant of any of items 15 to 30, the composition of any of items 31 to 40 or the granule of any of items 41 to 46, the animal feed additive of item 47 or the liquid formulation of any of items 48 to 54 and plant based material.   60. The animal feed of item 59, wherein the plant based material is from the sub-family Panicoideae.   61. The animal feed of item 60, wherein the plant based material from the sub-family Panicoideae is maize, corn,  Sorghum , switchgrass, millet, pearl millet, foxtail millet or in a processed form such as milled corn, milled maize, defatted maize, defatted destarched maize, milled  Sorghum , milled switchgrass, milled millet, milled foxtail millet, milled pearl millet, or any combination thereof.   62. The animal feed of any of items 60 to 61, wherein the plant based material from the sub-family Panicoideae is from the seed fraction (such as endosperm and/or husk) of the plant.   63. A pelleted animal feed prepared using the method of any of items 55 to 58 or by pelleting the animal feed of any of items 59 to 62.   64. A method of improving one or more performance parameters of an animal comprising administering to one or more animals the xylanase variant of any of items 15 to 30, the composition of any of items 31 to 40 or the granule of any of items 41 to 46, the animal feed additive of item 47, the liquid formulation of any of items 48 to 54, the animal feed of any of items 59 to 62 or the pelleted animal feed of item 63.   65. A method of solubilizing xylan from plant based material, comprising treating plant based material from with the xylanase variant of any of items 15 to 30, the composition of any of items 31 to 40 or the granule of any of items 41 to 46, the animal feed additive of item 47 or the liquid formulation of any of items 48 to 54.   66. A method of releasing starch from plant based material, comprising treating plant based material with the xylanase variant of any of items 15 to 30, the composition of any of items 31 to 40 or the granule of any of items 41 to 46, the animal feed additive of item 47 or the liquid formulation of any of items 48 to 54.   67. A method for improving the nutritional value of an animal feed, comprising adding to the feed comprising plant based material the xylanase variant of any of items 15 to 30, the composition of any of items 31 to 40 or the granule of any of items 41 to 46, the animal feed additive of item 47 or the liquid formulation of any of items 48 to 54.   68. The method of any of items 64 to 67, wherein the plant based material is from the sub-family Panicoideae.   69. The method of item 68, wherein the plant based material from the sub-family Panicoideae is maize, corn,  Sorghum , switchgrass, millet, pearl millet, foxtail millet or in a processed form such as milled corn, milled maize, defatted maize, defatted destarched maize, milled  Sorghum , milled switchgrass, milled millet, milled foxtail millet, milled pearl millet, or any combination thereof.   70. The method of any of items 68 to 69, wherein the plant based material from the sub-family Panicoideae is from the seed fraction (such as endosperm and/or husk) of the plant.   71. Use of the xylanase variant of any of items 15 to 30, the composition of any of items 31 to 40 or the granule of any of items 41 to 46, the animal feed additive of item 47, the liquid formulation of any of items 48 to 54, the animal feed of any of items 59 to 62 or the pelleted animal feed of item 63:
       in animal feed;   in animal feed additives;   in the preparation of a composition for use in animal feed;   for improving the nutritional value of an animal feed;   for increasing digestibility of an animal feed;   for improving one or more performance parameters in an animal;   for solubilizing xylan from plant based material   for releasing starch from plant based material.   
       72. The use of item 71, wherein the plant based material is from the sub-family Panicoideae.   73. The use of item 72, wherein the plant based material from the sub-family Panicoideae is maize, corn,  Sorghum , switchgrass, millet, pearl millet, foxtail millet or in a processed form such as milled corn, milled maize, defatted maize, defatted destarched maize, milled  Sorghum , milled switchgrass, milled millet, milled foxtail millet, milled pearl millet, or any combination thereof.   74. The use of any of items 72 to 73, wherein the plant based material from the sub-family Panicoideae is from the seed fraction (such as endosperm and/or husk) of the plant.   75. A process of producing a fermentation product, comprising the following steps:
       (a) saccharifying a starch-containing material at a temperature below the initial gelatinization temperature with an alpha-amylase, a glucoamylase, and a xylanase variant of any of items 15 to 30; and   (b) fermenting using a fermentation organism.   
       76. A process for producing a fermentation product from starch-containing material comprising the steps of:
       (a) liquefying a starch-containing material with an alpha-amylase;   (b) saccharifying the liquefied material obtained in step (a) with a glucoamylase and a xylanase variant of any of items 15 to 30;   (c) fermenting using a fermenting organism.   
       77. The process of any of items 75 or 76, wherein saccharification and fermentation is performed simultaneously.   78. The process of any of items 75 to 77, wherein the starch containing material comprises maize, corn, wheat, rye, barley, triticale,  Sorghum , switchgrass, millet, pearl millet, foxtail millet.   79. The process of any of items 75 to 78, wherein the fermentation product is alcohol, particularly ethanol.   80. The process of any of items 75 to 79 wherein the fermenting organism is yeast, particularly  Saccharomyces  sp., more particularly  Saccharomyces cerevisiae.      81. The use of a xylanase variant of any of items 15 to 30 for producing ethanol from a starch containing material.   82. A method for preparing a dough or a baked product prepared from the dough which method comprises incorporating into the dough a xylanase variant of any of items 15 to 30.   83. The method of item 82, wherein the dough comprises flour selected from the group consisting of wheat, barley, rye, oat, corn,  Sorghum , rice, millet, and any mixtures thereof.   84. An isolated polynucleotide encoding the xylanase variant of any of items 15 to 30, wherein the polynucleotide is operably linked to one or more control sequences that direct the production of the xylanase variant in a recombinant host cell.   85. A nucleic acid construct comprising the polynucleotide of item 84.   86. An expression vector comprising the polynucleotide of item 84.   87. A recombinant host cell comprising a nucleic acid construct of item 85 or expression vector of item 86.   88. A method of producing a xylanase variant, comprising:
       a. cultivating the host cell of item 87 under conditions suitable for expression of the xylanase variant; and   b. recovering the xylanase variant.   
       89. A transgenic plant, plant part or plant cell transformed with the polynucleotide of item 84.   90. A method of producing a xylanase variant of any of items 15 to 30, comprising:
       a. cultivating a transgenic plant or a plant cell comprising a polynucleotide encoding the xylanase variant under conditions conducive for production of the xylanase variant; and   b. recovering the xylanase variant.   
       91. A polynucleotide encoding the xylanase variant of any of items 15 to 30.   92. A nucleic acid construct or expression vector comprising the polynucleotide of item 91 operably linked to one or more control sequences that direct the production of the polypeptide in an expression host.   93. A recombinant host cell comprising the polynucleotide of item 91 operably linked to one or more control sequences that direct the production of the polypeptide.   94. A method of producing the xylanase variant of any of items 15 to 30, comprising:
       (a) cultivating a cell, which in its wild-type form produces the polypeptide, under conditions conductive for production of the polypeptide; and   (b) recovering the polypeptide.   
       95. A method of producing the xylanase variant of any of items 15 to 30, comprising:
       (a) cultivating the recombinant host cell of item 93 under conditions conducive for production of the polypeptide; and   (b) recovering the polypeptide.   
       96. A whole broth formulation or cell culture composition comprising the xylanase variant of any of items 15 to 30.   97. A method for preparing improved xylanase variants, comprising:
       a) determining an optimum protein charge range for a selected property, by testing a plurality of substituted xylanase variants for said selected property, wherein the xylanase variants having a net charge change of
           i) 0, −1 or −2, or   ii) +1 or +2   relative to the parent enzyme, for the property of interest; and   
           b) modifying at least one amino acid residue at one or more positions to yield more than one xylanase variant having a more positive charge or a more negative charge compared to the parent xylanase so that each of the xylanase variants have the optimum charge as determined in part a); and   c) assessing the relevant property of the xylanase variants from step b) to identify a xylanase variant that exhibits selected property in said test of interest as compared to the parent xylanase.   
       98. The method of item 97, wherein the xylanase variant has at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NO: 1.   99. The method of any of items 97 to 98, wherein the parent xylanase has at least 70%, e.g., at at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 1.   100. The method of any of items 97 to 99, wherein the parent xylanase is obtained or obtainable from the taxonomic order Bacillales, preferably the taxonomic family Bacillaceae.   101. The method of any of items 97 to 100, wherein the parent xylanase is obtained or obtainable from the taxonomic genus  Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis  or  Paenibacillus pabuli.      102. The method of any of items 97 to 101, wherein the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 1 or is a fragment of SEQ ID NO: 1, wherein the fragment has xylanase activity.   103. The method of any of items 97 to 101, wherein the parent xylanase comprises the amino acid sequence of SEQ ID NO: 1 and an N- and/or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids.   104. The method of any of items 97 to 103, wherein one or more position modified in step b) have a solvent accessible surface of greater than 50% on the surface of said parent enzyme.   105. The method of any of items 97 to 104, wherein the xylanase variant has an improved property relative to the parent, wherein the improved property is selected from the group consisting of catalytic efficiency, catalytic rate, chemical stability, oxidation stability, pH activity, pH stability, specific activity, stability under storage conditions, substrate binding, substrate cleavage, substrate specificity, substrate stability, surface properties, thermal activity, and thermostability.   106. A method for producing improved xylanase variants, comprising:
       a) testing a plurality of singly-altered xylanase variants in a selected test for a selected property, wherein the property of a parent enzyme is given a value of 1.0, and a favorable property has a value greater than 1.0;   b) identifying an alteration in at least one of the singly-altered xylanase variants that is associated with a selected property; and   c) introducing the alteration from step b) into a xylanase to yield an altered xylanase variant; and   d) testing the altered xylanase variant in a selected test, optionally selecting an altered xylanase variant having a favorable property.   
       107. The method of item 106, wherein the method includes a test for a second property and includes step b) identifying an alteration in at least one of the singly-altered xylanase variants that is associated with a selected second property, preferably wherein the second property isn&#39;t associated with an unduly unfavorable first property.   108. The method of item 107, wherein step b) is repeated any number of times (such as 1 to 10 times) and may be tested for any number of properties to create multi-altered enzyme variants.   109. The method of any of claims  106  to  108 , wherein the alteration is a substitution.   110. The method of item 109, wherein the alteration is a substitution and the at least one substitution comprises a net charge change of 0, −1, or −2 relative to the parent enzyme.   111. The method of item 109, wherein the alteration is a substitution and the at least one substitution comprises a net charge change of 0, +1 or +2 relative to the parent enzyme.   112. The method of any of claims  107  to  111 , wherein:
       (a) the value of the favorable property for the first and second test are both greater than 1.0;   (b) the value of the favorable property for the first test is greater than 1.1 and the value of the favorable property for the second test is greater than 0.9; or   (c) the value of the favorable property for the first test is greater than 0.9 and the value of the favorable property for the second test is greater than 1.1.   
       113. The method of any of claims  106  to  112 , wherein the xylanase variant has at least 75%, e.g., at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NO: 1.   114. The method of any of items 106 to 113, wherein the parent xylanase has at least 70%, e.g., at at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 1.   115. The method of any of items 106 to 114, wherein the parent xylanase is obtained or obtainable from the taxonomic order Bacillales, preferably the taxonomic family Bacillaceae.   116. The method of any of items 106 to 115, wherein the parent xylanase is obtained or obtainable from the taxonomic genus  Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis  or  Paenibacillus pabuli.      117. The method of any of items 106 to 116, wherein the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 1 or is a fragment of SEQ ID NO: 1, wherein the fragment has xylanase activity.   118. The method of any of items 106 to 116, wherein the parent xylanase comprises the amino acid sequence of SEQ ID NO: 1 and an N- and/or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids.   119. The method of any of items 106 to 118, wherein the xylanase variant has an improved property relative to the parent, wherein the improved property is selected from the group consisting of catalytic efficiency, catalytic rate, chemical stability, oxidation stability, pH activity, pH stability, specific activity, stability under storage conditions, substrate binding, substrate cleavage, substrate specificity, substrate stability, surface properties, thermal activity, and thermostability.   120. A process for reducing the viscosity of a post-fermentation process stream comprising the steps of:
       (a) producing a fermentation product according to any one of items 75 to 80, wherein a saccharified starch-containing material is fermented in the presence of a fermenting organism to produce a fermented mash;   (b) recovering a fermentation product from the fermented mash to form a whole stillage stream;   (c) separating the whole stillage stream into a thin stillage stream and wet cake;   (d) optionally evaporating the thin stillage stream to form at least a syrup stream; and   (e) adding a xylanase variant of any one of items 15 to 30 to one or more of the saccharified starch-containing material or fermented mash in step (a), the whole stillage stream formed in step (b), the thin stillage stream formed in step (c), and/or the syrup stream optionally formed in step (d), thereby reducing the viscosity of the fermented mash, the whole stillage stream, the thin stillage stream, and/or optionally the syrup stream.   
       121. The process of item 120, wherein the xylanase variant is added to the saccharified starch-containing material or fermented mash in step (a).   122. The process of item 120 or 121, wherein the xylanase variant is added to the whole stillage stream formed in step (b).   123. The process of any one of items 120 to 122, wherein the xylanase variant is added to the thin stillage stream formed in step (c).   124. The process of any one of items 120 to 123, wherein optional step (d) is performed and the xylanase variant is added to the syrup stream.   125. The process of any one of items 120 to 124, further comprising adding an additional enzyme to one or more of the saccharified starch-containing material or fermented mash in step (a), the whole stillage stream formed in step (b), the thin stillage stream formed in step (c), and/or the syrup stream optionally formed in step (d), wherein the additional enzyme is selected from the group consisting of an amylase, a xyloglucanase, a cellulase, a pectinase, an endoglucanase, a beta-glucosidase, and mixtures thereof.   126. Use of a xylanase variant according to any one of items 15 to 30 for reducing the viscosity of a post-fermentation process stream.   127. Use according to item 126, wherein the post-fermentation process stream is selected from the group consisting of a whole stillage stream, a thin stillage stream, and a syrup stream.   128. Use according to item 125 or 126, wherein an additional enzyme is used in combination with the xylanase variant, wherein the additional enzyme is selected from the group consisting of an amylase, a xyloglucanase, a cellulase, a pectinase, an endoglucanase, a beta-glucosidase, and mixtures thereof.   

     EXAMPLES 
     Substrates 
     Preparation of Destarched Maize (DSM) 
     107 kg of milled maize (&lt;10 mm) is mixed in a tank with 253 kg of tap water at 53° C. to make a slurry. The temperature of the slurry is 47° C. and the pH 5.9. The pH is adjusted to 6.15 with 1 L of 1 N NaOH and the tank is then heated to 95° C. 1.119 kg of Termamyl® alpha-amylase (Novozymes A/S, Bagsvaerd, Denmark) is added at 52° C. and incubated for 80 minutes at 95° C. The pH measured at the end of the incubation is 6.17. Cold tap water is added to the slurry and the slurry is centrifuged and decanted 3 times using a Westfalia decanter CA-225-110 (4950±10 rpm, flow ˜600 l/h) giving 64.5 kg of sludge. The sludge is then collected, frozen and freeze-dried to give 17.1 kg of destarched maize (DSM). 
     Preparation of Defatted Destarched Maize (DFDSM) 
     500 mL acetone is added to 100 grams of destarched maize, prepared as described above. The slurry is stirred for 5 minutes and allowed to settle. The acetone is decanted and the procedure repeated 2 times. The residue is air dried overnight to give defatted destarched maize (DFDSM) which is stored at room temperature. 
     Preparation of Destarched  Sorghum    
     Whole  Sorghum  seeds are milled and sieved and a fraction below 0.5 mm is used for further processing. The sieved fraction is suspended in 25 mM NaOAc pH 5.5 at 20% dry matter and destarched. The destarching involves a first step at 85° C. with 500 ppm Termamyl SC alpha-amylase (Novozymes A/S, Bagsvaerd, Denmark) for 20 min followed by an overnight incubation using 250 ppm Attenuzyme Flex (Novozymes A/S, Bagsvaerd, Denmark) at 65° C. The slurry is centrifuged and the liquid decanted. After this another destarching is made using by adding MilliQ water and 200 ppm Termamyl SC and 200 ppm Attenuzyme Flex and incubating overnight at 65° C. 
     The  Sorghum  fiber is separated from the liquid by vacuum filtration through a Whatman F glass fiber filter. The filter cake is then washed several times with excess of water to remove soluble sugars. Finally the destarched  Sorghum  fiber was dried in an oven at 65° C. and the dry fiber milled quickly in a coffee grinder so that the particle size is in general less than 1 mm. 
     Xylose Solubilization Assay 
     The activity of a xylanase variant towards defatted destarched Maize (DFDSM) is measured by High-Performance Anion-Exchange Chromatography with Pulsed Amperometric Detection (HPAE-PAD). 2% (w/w) DFDSM suspension is prepared in 100 mM sodium acetate, 5 mM CaCl 2 , pH 5 and allowed to hydrate for 30 minutes at room temperature under gently stirring. After hydration, 200 μl substrate suspension was pipetted into a 96 well plate and mixed with 20 μl enzyme solution to obtain a final enzyme concentration of 20 PPM relative to substrate (20 μg enzyme/g substrate). The enzyme/substrate mixtures are left for hydrolysis in 2.5 hours at 40° C. under gently agitation (500 RPM) in a plate incubator (Biosan PST-100 HL). After enzymatic hydrolysis, the enzyme/substrate plates are centrifuged for 10 minutes at 3000 RPM and 50 μl supernatant (hydrolysate) is mixed with 100 μl 1.6 M HCl and transferred to 300 μl PCR tubes and left for acid hydrolysis for 40 minutes at 90° C. in a PCR machine. The purpose of the acid hydrolysis is to convert soluble polysaccharides, released by the xylanase variant, into mono-saccharides, which can be quantified using HPAE-PAD. Samples are neutralized with 125 μl 1.4 M NAOH after acid hydrolysis and mounted on the HPAE-PAD for mono-saccharide analysis (xylose, arabinose and glucose) (Dionex ICS-3000 using a CarboPac PA1 column). Appropriate calibration curves are made using mono-saccharides stock solutions which are subjected to the same procedure of acid hydrolysis as the samples. The percentage xylose solubilized is calculated according to the equation: 
     
       
         
           
             
               % 
               ⁢ 
                   
               Xylose 
               ⁢ 
                   
               solubulized 
             
             = 
             
               
                 
                   [ 
                   Xylose 
                   ] 
                 
                 * 
                 V 
                 * 
                 M 
                 ⁢ 
                 W 
               
               
                 X 
                 ⁢ 
                 x 
                 ⁢ 
                 y 
                 ⁢ 
                 l 
                 * 
                 M 
                 ⁢ 
                 s 
                 ⁢ 
                 u 
                 ⁢ 
                 b 
               
             
           
         
       
     
     where [xylose] denotes the concentration of xylose in the supernatant measured by HPAE-PAD, V the volume of the sample, MW, the molecular weight of internal xylose in arabino-xylan (132 g/mol), Xxyl, the fraction of xylose in DFDSM (0.102) and Msub, the mass of DFDSM in the sample. 
     Example 1: Construction of Variants by Site-Directed Mutagenesis 
     Site-directed variants were constructed of the  Bacillus subtilis  xylanase (SEQ ID NO: 1), comprising specific substitutions according to the invention. The variants were made by traditional cloning of DNA fragments (Sambrook et al., Molecular Cloning: A Laboratory Manual, 2nd Ed., Cold Spring Harbor, 1989) using PCR together with properly designed mutagenic oligonucleotides that introduced the desired mutations in the resulting sequence. Mutagenic oligos were designed corresponding to the DNA sequence flanking the desired site(s) of mutation, separated by the DNA base pairs defining the insertions/deletions/substitutions, and purchased from an oligo vendor such as Life Technologies. In order to test the xylanase variants of the invention, the mutated DNA comprising a variant of the invention were integrated into a competent  B. subtilis  strain by homologous recombination, fermented using standard protocols (yeast extract based media, 3-4 days, 30° C.), and screened as described in Example 2. 
     Example 2: Protein Thermal Unfolding Analysis (TSA, Thermal Shift Assay) of Culture Broth Samples 
     Protein thermal unfolding was monitored with Sypro Orange (Invitrogen, S-6650) using a real-time PCR instrument (Applied Biosystems; Step-One-Plus). 
     Culture broth samples were flocculated and diluted prior to TSA analysis: 
     To Culture broth was added 4 v/v-% GC850™ (Al 2 (OH) 5 Cl) obtainable from Gulbrandsen or NordPac 18 (available from Nordisk Aluminat A/S, Denmark)), mixed and spun down. 
     To the supernatant was added 10 v/v-% 1.0 M HCl, followed by 8-fold dilution in buffer: 100 mM formic acid/sodium formate pH 3.77+50 mM NaCl. 
     In a 96-well white PCR-plate, 15 μl sample (flocculated and diluted) was mixed (1:1) with Sypro Orange (Conc.=10×; stock solution from supplier=5000×) in buffer. 
     The plate was sealed with an optical PCR seal. The PCR instrument was set at a scan-rate of 76° C. per hour, starting at 25° C. and finishing at 96° C. 
     Fluorescence was monitored every 20 seconds using in-built LED blue light for excitation and ROX-filter (610 nm, emission). 
     Tm-values were calculated as the maximum value of the first derivative (dF/dK) (Gregory et al., 2009 , J. Biomol. Screen.  14: 700). 
     The Delta Tm is the difference between the Tm of the xylanase variant and the Tm of the wild-type xylanase and are presented in table 2 below. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Protein thermal unfolding of xylanase variants of SEQ ID NO: 1 
               
            
           
           
               
               
               
            
               
                   
                 Alteration 
                 ΔTm (° C.) 
               
               
                   
                   
               
            
           
           
               
               
               
            
               
                   
                 A2D 
                 3.6 
               
               
                   
                 A2Q 
                 1.6 
               
               
                   
                 A2G 
                 1.3 
               
               
                   
                 A2W 
                 1.2 
               
               
                   
                 A2P 
                 1.2 
               
               
                   
                 A2L 
                 0.5 
               
               
                   
                 A2Y 
                 0.4 
               
               
                   
                 S3W 
                 1.0 
               
               
                   
                 S3F 
                 1.0 
               
               
                   
                 S3H 
                 0.7 
               
               
                   
                 S3L 
                 0.6 
               
               
                   
                 S3G 
                 0.4 
               
               
                   
                 S3M 
                 0.4 
               
               
                   
                 S3T 
                 0.2 
               
               
                   
                 S3P 
                 0.1 
               
               
                   
                 D4L 
                 3.2 
               
               
                   
                 D4C 
                 1.8 
               
               
                   
                 D4Y 
                 0.4 
               
               
                   
                 D4Q 
                 0.3 
               
               
                   
                 D4A 
                 0.2 
               
               
                   
                 D4K 
                 0.2 
               
               
                   
                 D4P 
                 0.1 
               
               
                   
                 V5H 
                 1.1 
               
               
                   
                 V5G 
                 0.5 
               
               
                   
                 V5P 
                 0.3 
               
               
                   
                 T6K 
                 1.3 
               
               
                   
                 T6Q 
                 1.0 
               
               
                   
                 T6L 
                 0.7 
               
               
                   
                 T6N 
                 0.6 
               
               
                   
                 T6R 
                 0.5 
               
               
                   
                 T6D 
                 0.4 
               
               
                   
                 T6F 
                 0.4 
               
               
                   
                 T6H 
                 0.2 
               
               
                   
                 V7F 
                 0.8 
               
               
                   
                 V7S 
                 0.8 
               
               
                   
                 V7C 
                 0.8 
               
               
                   
                 V7A 
                 0.7 
               
               
                   
                 V7W 
                 0.2 
               
               
                   
                 N8Q 
                 1.2 
               
               
                   
                 N8R 
                 1.1 
               
               
                   
                 N8D 
                 1.0 
               
               
                   
                 N8F 
                 0.9 
               
               
                   
                 N8W 
                 0.9 
               
               
                   
                 N8Y 
                 0.9 
               
               
                   
                 N8S 
                 0.7 
               
               
                   
                 N8M 
                 0.6 
               
               
                   
                 N8L 
                 0.6 
               
               
                   
                 N8V 
                 0.5 
               
               
                   
                 N8T 
                 0.4 
               
               
                   
                 N8I 
                 0.3 
               
               
                   
                 N8A 
                 0.3 
               
               
                   
                 V9H 
                 1.8 
               
               
                   
                 V9R 
                 0.8 
               
               
                   
                 V9M 
                 0.8 
               
               
                   
                 S10A 
                 1.3 
               
               
                   
                 S10H 
                 1.2 
               
               
                   
                 S10L 
                 0.7 
               
               
                   
                 S10I 
                 0.5 
               
               
                   
                 S10D 
                 0.3 
               
               
                   
                 S10K 
                 0.2 
               
               
                   
                 S10V 
                 0.1 
               
               
                   
                 A11P 
                 1.8 
               
               
                   
                 A11I 
                 1.5 
               
               
                   
                 A11N 
                 1.4 
               
               
                   
                 A11G 
                 1.3 
               
               
                   
                 A11Y 
                 1.2 
               
               
                   
                 A11C 
                 1.1 
               
               
                   
                 A11S 
                 1.1 
               
               
                   
                 A11F 
                 1.0 
               
               
                   
                 A11M 
                 0.9 
               
               
                   
                 A11D 
                 0.7 
               
               
                   
                 A11L 
                 0.6 
               
               
                   
                 A11H 
                 0.6 
               
               
                   
                 A11W 
                 0.6 
               
               
                   
                 A11E 
                 0.5 
               
               
                   
                 A11V 
                 0.4 
               
               
                   
                 A11R 
                 0.4 
               
               
                   
                 A11Q 
                 0.1 
               
               
                   
                 E12G 
                 1.5 
               
               
                   
                 E12R 
                 1.4 
               
               
                   
                 E12K 
                 1.0 
               
               
                   
                 E12T 
                 0.7 
               
               
                   
                 E12V 
                 0.6 
               
               
                   
                 E12W 
                 0.6 
               
               
                   
                 E12C 
                 0.1 
               
               
                   
                 K13Q 
                 1.1 
               
               
                   
                 K13H 
                 1.0 
               
               
                   
                 K13N 
                 0.5 
               
               
                   
                 K13L 
                 0.2 
               
               
                   
                 K13S 
                 0.1 
               
               
                   
                 Q14K 
                 2.8 
               
               
                   
                 Q14Y 
                 2.7 
               
               
                   
                 Q14A 
                 2.3 
               
               
                   
                 Q14V 
                 2.2 
               
               
                   
                 Q14W 
                 2.1 
               
               
                   
                 Q14F 
                 1.9 
               
               
                   
                 Q14S 
                 1.7 
               
               
                   
                 Q14P 
                 1.5 
               
               
                   
                 Q14G 
                 1.3 
               
               
                   
                 Q14R 
                 1.0 
               
               
                   
                 Q14M 
                 0.7 
               
               
                   
                 Q14H 
                 0.7 
               
               
                   
                 Q14C 
                 0.6 
               
               
                   
                 Q14D 
                 0.2 
               
               
                   
                 V15F 
                 0.8 
               
               
                   
                 V15L 
                 0.8 
               
               
                   
                 V15N 
                 0.7 
               
               
                   
                 V15K 
                 0.6 
               
               
                   
                 V15H 
                 0.2 
               
               
                   
                 G18H 
                 4.5 
               
               
                   
                 G18Y 
                 1.8 
               
               
                   
                 G18W 
                 1.4 
               
               
                   
                 G18F 
                 1.2 
               
               
                   
                 G18C 
                 0.9 
               
               
                   
                 G18S 
                 0.9 
               
               
                   
                 G18A 
                 0.2 
               
               
                   
                 F19H 
                 0.4 
               
               
                   
                 F19Y 
                 0.1 
               
               
                   
                 L31Q 
                 1.6 
               
               
                   
                 L31H 
                 1.5 
               
               
                   
                 L31P 
                 1.3 
               
               
                   
                 L31G 
                 1.2 
               
               
                   
                 L31S 
                 1.1 
               
               
                   
                 L31R 
                 0.8 
               
               
                   
                 L31N 
                 0.7 
               
               
                   
                 L31I 
                 0.6 
               
               
                   
                 L31V 
                 0.1 
               
               
                   
                 T32N 
                 0.5 
               
               
                   
                 T32D 
                 0.5 
               
               
                   
                 A33Q 
                 1.0 
               
               
                   
                 A33H 
                 1.0 
               
               
                   
                 A33M 
                 1.0 
               
               
                   
                 A33Y 
                 0.8 
               
               
                   
                 A33K 
                 0.5 
               
               
                   
                 A33E 
                 0.3 
               
               
                   
                 A33R 
                 0.3 
               
               
                   
                 A33C 
                 0.2 
               
               
                   
                 A33N 
                 0.2 
               
               
                   
                 A34F 
                 1.2 
               
               
                   
                 A34N 
                 0.5 
               
               
                   
                 A34C 
                 0.5 
               
               
                   
                 A34L 
                 0.3 
               
               
                   
                 A34P 
                 0.2 
               
               
                   
                 A34S 
                 0.2 
               
               
                   
                 A34Q 
                 0.1 
               
               
                   
                 A39S 
                 0.2 
               
               
                   
                 G43W 
                 1.3 
               
               
                   
                 G43A 
                 0.9 
               
               
                   
                 G43N 
                 0.6 
               
               
                   
                 Q44D 
                 0.5 
               
               
                   
                 Q44N 
                 0.2 
               
               
                   
                 Q44R 
                 0.2 
               
               
                   
                 Q44Y 
                 0.1 
               
               
                   
                 Q44K 
                 0.1 
               
               
                   
                 N45D 
                 1.5 
               
               
                   
                 N45W 
                 1.4 
               
               
                   
                 N45S 
                 1.3 
               
               
                   
                 N45F 
                 1.2 
               
               
                   
                 N45I 
                 0.9 
               
               
                   
                 N45E 
                 0.7 
               
               
                   
                 N45H 
                 0.7 
               
               
                   
                 N45Q 
                 0.5 
               
               
                   
                 N45G 
                 0.4 
               
               
                   
                 N45P 
                 0.4 
               
               
                   
                 N45T 
                 0.4 
               
               
                   
                 N45Y 
                 0.2 
               
               
                   
                 Q46D 
                 1.3 
               
               
                   
                 Q46H 
                 1.3 
               
               
                   
                 Q46C 
                 0.7 
               
               
                   
                 Q46S 
                 0.6 
               
               
                   
                 Q46T 
                 0.6 
               
               
                   
                 Q46N 
                 0.5 
               
               
                   
                 Q46K 
                 0.2 
               
               
                   
                 G48L 
                 1.8 
               
               
                   
                 G48V 
                 1.4 
               
               
                   
                 G48I 
                 0.9 
               
               
                   
                 G48Q 
                 0.8 
               
               
                   
                 G48C 
                 0.4 
               
               
                   
                 S50H 
                 7.0 
               
               
                   
                 S50F 
                 6.4 
               
               
                   
                 S50R 
                 5.4 
               
               
                   
                 S50K 
                 5.2 
               
               
                   
                 S50I 
                 5.2 
               
               
                   
                 S50L 
                 4.9 
               
               
                   
                 S50Q 
                 4.8 
               
               
                   
                 S50Y 
                 4.7 
               
               
                   
                 S50N 
                 4.7 
               
               
                   
                 S50V 
                 4.7 
               
               
                   
                 S50M 
                 4.5 
               
               
                   
                 S50P 
                 3.9 
               
               
                   
                 S50A 
                 3.6 
               
               
                   
                 S50C 
                 3.5 
               
               
                   
                 S50G 
                 3.4 
               
               
                   
                 S50D 
                 3.2 
               
               
                   
                 S50E 
                 2.6 
               
               
                   
                 S50T 
                 1.8 
               
               
                   
                 E58P 
                 1.0 
               
               
                   
                 E58K 
                 0.6 
               
               
                   
                 E58R 
                 0.4 
               
               
                   
                 N59C 
                 1.8 
               
               
                   
                 N59V 
                 1.3 
               
               
                   
                 N59D 
                 1.2 
               
               
                   
                 N59K 
                 0.9 
               
               
                   
                 N59L 
                 0.2 
               
               
                   
                 N59S 
                 0.2 
               
               
                   
                 N61W 
                 2.3 
               
               
                   
                 N61L 
                 1.8 
               
               
                   
                 N61D 
                 1.4 
               
               
                   
                 N61E 
                 1.2 
               
               
                   
                 N61H 
                 1.1 
               
               
                   
                 N61M 
                 0.9 
               
               
                   
                 N61Y 
                 0.9 
               
               
                   
                 N61I 
                 0.6 
               
               
                   
                 N61T 
                 0.5 
               
               
                   
                 N61F 
                 0.2 
               
               
                   
                 N61Q 
                 0.1 
               
               
                   
                 N62A 
                 1.1 
               
               
                   
                 N62V 
                 1.1 
               
               
                   
                 N62L 
                 1.1 
               
               
                   
                 N62C 
                 1.0 
               
               
                   
                 N62T 
                 1.0 
               
               
                   
                 N62Y 
                 0.9 
               
               
                   
                 N62F 
                 0.9 
               
               
                   
                 N62M 
                 0.8 
               
               
                   
                 N62W 
                 0.6 
               
               
                   
                 N62Q 
                 0.5 
               
               
                   
                 Y64F 
                 0.3 
               
               
                   
                 Y64N 
                 0.2 
               
               
                   
                 K65I 
                 1.0 
               
               
                   
                 K65L 
                 0.7 
               
               
                   
                 V67A 
                 1.4 
               
               
                   
                 V67S 
                 1.3 
               
               
                   
                 V67F 
                 0.9 
               
               
                   
                 V67G 
                 0.4 
               
               
                   
                 V67K 
                 0.1 
               
               
                   
                 E68W 
                 1.0 
               
               
                   
                 E68V 
                 0.6 
               
               
                   
                 E68I 
                 0.6 
               
               
                   
                 E68A 
                 0.2 
               
               
                   
                 E68H 
                 0.2 
               
               
                   
                 E68N 
                 0.2 
               
               
                   
                 I79K 
                 2.0 
               
               
                   
                 I79R 
                 0.6 
               
               
                   
                 I79V 
                 0.5 
               
               
                   
                 I79A 
                 0.4 
               
               
                   
                 A82G 
                 0.7 
               
               
                   
                 P88M 
                 1.8 
               
               
                   
                 P88F 
                 1.5 
               
               
                   
                 P88T 
                 0.9 
               
               
                   
                 P88W 
                 0.5 
               
               
                   
                 P88Q 
                 0.2 
               
               
                   
                 D90R 
                 0.2 
               
               
                   
                 T94H 
                 2.7 
               
               
                   
                 T101L 
                 1.7 
               
               
                   
                 T101R 
                 1.7 
               
               
                   
                 S102R 
                 3.9 
               
               
                   
                 K104R 
                 1.8 
               
               
                   
                 K104H 
                 0.8 
               
               
                   
                 K110E 
                 0.7 
               
               
                   
                 K110M 
                 0.6 
               
               
                   
                 A112G 
                 1.1 
               
               
                   
                 A112T 
                 0.7 
               
               
                   
                 A112V 
                 0.4 
               
               
                   
                 A113E 
                 1.3 
               
               
                   
                 A113Q 
                 1.1 
               
               
                   
                 A113L 
                 0.7 
               
               
                   
                 A113D 
                 0.4 
               
               
                   
                 A113S 
                 0.2 
               
               
                   
                 Q116E 
                 1.0 
               
               
                   
                 Q116A 
                 0.8 
               
               
                   
                 Q116G 
                 0.6 
               
               
                   
                 N119G 
                 0.6 
               
               
                   
                 N119S 
                 0.5 
               
               
                   
                 N119V 
                 0.5 
               
               
                   
                 N119L 
                 0.3 
               
               
                   
                 N119C 
                 0.3 
               
               
                   
                 N119R 
                 0.2 
               
               
                   
                 D120R 
                 1.4 
               
               
                   
                 D120A 
                 1.3 
               
               
                   
                 D120S 
                 1.0 
               
               
                   
                 D120Y 
                 0.7 
               
               
                   
                 D120L 
                 0.7 
               
               
                   
                 D120W 
                 0.5 
               
               
                   
                 D120T 
                 0.4 
               
               
                   
                 D120G 
                 0.2 
               
               
                   
                 T123E 
                 1.0 
               
               
                   
                 T123Y 
                 0.8 
               
               
                   
                 T123C 
                 0.6 
               
               
                   
                 T123H 
                 0.5 
               
               
                   
                 T123Q 
                 0.2 
               
               
                   
                 T123K 
                 0.2 
               
               
                   
                 T123V 
                 0.2 
               
               
                   
                 T123G 
                 0.1 
               
               
                   
                 T123R 
                 0.1 
               
               
                   
                 T123I 
                 0.1 
               
               
                   
                 K126R 
                 0.8 
               
               
                   
                 K126A 
                 0.4 
               
               
                   
                 K126Y 
                 0.4 
               
               
                   
                 K126L 
                 0.4 
               
               
                   
                 K126F 
                 0.3 
               
               
                   
                 K126W 
                 0.3 
               
               
                   
                 K126E 
                 0.3 
               
               
                   
                 K126H 
                 0.3 
               
               
                   
                 K126Q 
                 0.1 
               
               
                   
                 N127P 
                 0.3 
               
               
                   
                 N127W 
                 0.2 
               
               
                   
                 N128H 
                 1.3 
               
               
                   
                 N128K 
                 0.3 
               
               
                   
                 G129M 
                 0.7 
               
               
                   
                 G129Q 
                 0.6 
               
               
                   
                 G129A 
                 0.3 
               
               
                   
                 G129F 
                 0.3 
               
               
                   
                 G129W 
                 0.1 
               
               
                   
                 N131K 
                 0.2 
               
               
                   
                 N131R 
                 0.2 
               
               
                   
                 I135T 
                 0.8 
               
               
                   
                 Y143H 
                 3.7 
               
               
                   
                 Y143R 
                 2.5 
               
               
                   
                 Y143N 
                 0.9 
               
               
                   
                 H145Y 
                 5.0 
               
               
                   
                 H145C 
                 0.9 
               
               
                   
                 H145K 
                 0.7 
               
               
                   
                 H145A 
                 0.7 
               
               
                   
                 H145W 
                 0.3 
               
               
                   
                 E146R 
                 3.1 
               
               
                   
                 E146H 
                 2.4 
               
               
                   
                 E146Y 
                 1.8 
               
               
                   
                 E146F 
                 1.6 
               
               
                   
                 E146W 
                 0.8 
               
               
                   
                 E146A 
                 0.6 
               
               
                   
                 E146K 
                 0.4 
               
               
                   
                 E146G 
                 0.3 
               
               
                   
                 E146S 
                 0.1 
               
               
                   
                 M159C 
                 1.6 
               
               
                   
                 R160I 
                 0.5 
               
               
                   
                 S165Y 
                 3.0 
               
               
                   
                 S165M 
                 2.1 
               
               
                   
                 S165I 
                 0.2 
               
               
                   
                 A168I 
                 0.7 
               
               
                   
                 A168R 
                 0.2 
               
               
                   
                 F176H 
                 12.7 
               
               
                   
                 F176R 
                 6.3 
               
               
                   
                 F176Y 
                 1.8 
               
               
                   
                 F176K 
                 1.7 
               
               
                   
                 F176W 
                 0.7 
               
               
                   
                 L179D 
                 7.0 
               
               
                   
                 L179N 
                 6.4 
               
               
                   
                 L179C 
                 3.6 
               
               
                   
                 L179A 
                 3.2 
               
               
                   
                 L179R 
                 1.5 
               
               
                   
                 L179K 
                 1.5 
               
               
                   
                 L179S 
                 1.5 
               
               
                   
                 L179Q 
                 0.6 
               
               
                   
                 L179W 
                 0.6 
               
               
                   
                 N181C 
                 2.0 
               
               
                   
                 N181A 
                 0.6 
               
               
                   
                 N181T 
                 0.2 
               
               
                   
                 N188M 
                 1.1 
               
               
                   
                 N188E 
                 0.3 
               
               
                   
                 N188L 
                 0.2 
               
               
                   
                 Q191I 
                 0.9 
               
               
                   
                 Q191K 
                 0.7 
               
               
                   
                 Q191V 
                 0.6 
               
               
                   
                 Q191R 
                 0.4 
               
               
                   
                 Q191L 
                 0.3 
               
               
                   
                 Q191M 
                 0.2 
               
               
                   
                 A194H 
                 1.1 
               
               
                   
                 A194R 
                 1.0 
               
               
                   
                 A194K 
                 0.9 
               
               
                   
                 N195H 
                 1.4 
               
               
                   
                 M196L 
                 11.7 
               
               
                   
                 M196I 
                 1.0 
               
               
                   
                 D197A 
                 4.5 
               
               
                   
                 D197S 
                 3.5 
               
               
                   
                 D197Q 
                 3.1 
               
               
                   
                 D197G 
                 2.0 
               
               
                   
                 D197P 
                 1.4 
               
               
                   
                 D197T 
                 0.8 
               
               
                   
                 D197N 
                 0.6 
               
               
                   
                 G205C 
                 0.2 
               
               
                   
                 G205Q 
                 0.2 
               
               
                   
                 S209N 
                 1.6 
               
               
                   
                 S209C 
                 1.6 
               
               
                   
                 S209W 
                 0.3 
               
               
                   
                 P212A 
                 1.6 
               
               
                   
                 P212K 
                 1.3 
               
               
                   
                 P212Q 
                 1.3 
               
               
                   
                 P212R 
                 1.3 
               
               
                   
                 P212E 
                 1.1 
               
               
                   
                 P212S 
                 0.6 
               
               
                   
                 P212N 
                 0.5 
               
               
                   
                 K217Q 
                 0.5 
               
               
                   
                 K217M 
                 0.1 
               
               
                   
                 Q218H 
                 0.9 
               
               
                   
                 Q218I 
                 0.5 
               
               
                   
                 A221R 
                 1.4 
               
               
                   
                 A221K 
                 1.4 
               
               
                   
                 A221H 
                 0.9 
               
               
                   
                 A221Q 
                 0.8 
               
               
                   
                 A221C 
                 0.4 
               
               
                   
                 A221N 
                 0.3 
               
               
                   
                 D224Q 
                 2.5 
               
               
                   
                 Y231T 
                 3.1 
               
               
                   
                 Y231V 
                 2.9 
               
               
                   
                 Y231S 
                 2.4 
               
               
                   
                 Y231A 
                 2.1 
               
               
                   
                 Y231C 
                 0.7 
               
               
                   
                 S235A 
                 1.8 
               
               
                   
                 S235G 
                 0.8 
               
               
                   
                 T237P 
                 1.2 
               
               
                   
                 T237R 
                 0.9 
               
               
                   
                 T237K 
                 0.8 
               
               
                   
                 N238G 
                 0.1 
               
               
                   
                 R242I 
                 0.7 
               
               
                   
                 Y269Q 
                 3.5 
               
               
                   
                 Y269M 
                 1.6 
               
               
                   
                 Y269I 
                 1.4 
               
               
                   
                 Y269F 
                 1.3 
               
               
                   
                 Y269L 
                 1.0 
               
               
                   
                 D280S 
                 0.9 
               
               
                   
                 D280N 
                 0.6 
               
               
                   
                 D280R 
                 0.4 
               
               
                   
                 T282M 
                 1.9 
               
               
                   
                 T282H 
                 1.1 
               
               
                   
                 T282R 
                 1.1 
               
               
                   
                 T282C 
                 1.0 
               
               
                   
                 T282V 
                 1.0 
               
               
                   
                 T282L 
                 0.9 
               
               
                   
                 T282E 
                 0.4 
               
               
                   
                 T282F 
                 0.3 
               
               
                   
                 K295W 
                 1.5 
               
               
                   
                 K295T 
                 0.5 
               
               
                   
                 K295I 
                 0.3 
               
               
                   
                 K295V 
                 0.1 
               
               
                   
                 R298Q 
                 2.1 
               
               
                   
                 R298A 
                 1.9 
               
               
                   
                 R298E 
                 1.8 
               
               
                   
                 R298M 
                 1.7 
               
               
                   
                 R298T 
                 1.7 
               
               
                   
                 R298N 
                 1.4 
               
               
                   
                 R298C 
                 1.4 
               
               
                   
                 R298I 
                 1.3 
               
               
                   
                 R298D 
                 1.1 
               
               
                   
                 R298L 
                 0.9 
               
               
                   
                 R298G 
                 0.7 
               
               
                   
                 R298W 
                 0.7 
               
               
                   
                 R298S 
                 0.6 
               
               
                   
                 R298P 
                 0.3 
               
               
                   
                 R298Y 
                 0.3 
               
               
                   
                 P299W 
                 4.5 
               
               
                   
                 P299A 
                 3.3 
               
               
                   
                 P299K 
                 2.7 
               
               
                   
                 P299F 
                 2.3 
               
               
                   
                 P299Y 
                 1.8 
               
               
                   
                 P299Q 
                 1.5 
               
               
                   
                 P299N 
                 1.5 
               
               
                   
                 P299H 
                 1.4 
               
               
                   
                 P299E 
                 1.3 
               
               
                   
                 P299D 
                 1.1 
               
               
                   
                 P299R 
                 1.0 
               
               
                   
                 P299M 
                 0.9 
               
               
                   
                 P299C 
                 0.5 
               
               
                   
                 P299G 
                 0.4 
               
               
                   
                 P299S 
                 0.1 
               
               
                   
                 G300A 
                 1.0 
               
               
                   
                 G300R 
                 0.7 
               
               
                   
                 V302I 
                 2.9 
               
               
                   
                 V302S 
                 2.1 
               
               
                   
                 V302R 
                 1.5 
               
               
                   
                 V302T 
                 1.5 
               
               
                   
                 V302A 
                 1.3 
               
               
                   
                 V302Q 
                 1.2 
               
               
                   
                 V302G 
                 1.1 
               
               
                   
                 V302C 
                 1.0 
               
               
                   
                 V302K 
                 0.9 
               
               
                   
                 V302W 
                 0.9 
               
               
                   
                 V302P 
                 0.6 
               
               
                   
                 V302D 
                 0.5 
               
               
                   
                 V302F 
                 0.3 
               
               
                   
                 D305W 
                 0.9 
               
               
                   
                 D305F 
                 0.7 
               
               
                   
                 D305I 
                 0.6 
               
               
                   
                 D305M 
                 0.2 
               
               
                   
                 A306I 
                 0.9 
               
               
                   
                 A306T 
                 0.8 
               
               
                   
                 T307I 
                 2.0 
               
               
                   
                 T307N 
                 1.7 
               
               
                   
                 T307R 
                 1.6 
               
               
                   
                 T307Q 
                 1.5 
               
               
                   
                 T307K 
                 1.4 
               
               
                   
                 T307F 
                 1.4 
               
               
                   
                 T307M 
                 1.3 
               
               
                   
                 T307D 
                 1.2 
               
               
                   
                 T307V 
                 1.0 
               
               
                   
                 T307W 
                 0.9 
               
               
                   
                 T307C 
                 0.9 
               
               
                   
                 T307S 
                 0.8 
               
               
                   
                 T307H 
                 0.8 
               
               
                   
                 T307E 
                 0.3 
               
               
                   
                 T307Y 
                 0.2 
               
               
                   
                 N311R 
                 1.5 
               
               
                   
                 N311M 
                 1.4 
               
               
                   
                 N311I 
                 1.1 
               
               
                   
                 N311C 
                 0.7 
               
               
                   
                 N311V 
                 0.6 
               
               
                   
                 A312I 
                 1.8 
               
               
                   
                 A312R 
                 1.5 
               
               
                   
                 A312M 
                 1.0 
               
               
                   
                 A312F 
                 0.7 
               
               
                   
                 N313D 
                 1.5 
               
               
                   
                 N313R 
                 0.9 
               
               
                   
                 N313I 
                 0.6 
               
               
                   
                 N313L 
                 0.5 
               
               
                   
                 N313C 
                 0.3 
               
               
                   
                 N313G 
                 0.1 
               
               
                   
                 N313F 
                 0.1 
               
               
                   
                 D322F 
                 1.6 
               
               
                   
                 D322G 
                 1.3 
               
               
                   
                 D322L 
                 0.3 
               
               
                   
                 N323A 
                 1.2 
               
               
                   
                 N323C 
                 0.6 
               
               
                   
                 N323Q 
                 0.4 
               
               
                   
                 N323L 
                 0.3 
               
               
                   
                 N323G 
                 0.3 
               
               
                   
                 N323R 
                 0.2 
               
               
                   
                 N323E 
                 0.2 
               
               
                   
                 N323S 
                 0.2 
               
               
                   
                 N323Y 
                 0.2 
               
               
                   
                 N323P 
                 0.1 
               
               
                   
                 K324S 
                 0.9 
               
               
                   
                 K324P 
                 0.7 
               
               
                   
                 S333I 
                 2.8 
               
               
                   
                 S333R 
                 1.7 
               
               
                   
                 S333T 
                 0.6 
               
               
                   
                 N334I 
                 1.5 
               
               
                   
                 N334A 
                 1.1 
               
               
                   
                 N334L 
                 0.3 
               
               
                   
                 T335I 
                 1.8 
               
               
                   
                 T335A 
                 0.8 
               
               
                   
                 G336C 
                 1.7 
               
               
                   
                 G336A 
                 0.5 
               
               
                   
                 G336E 
                 0.1 
               
               
                   
                 V337A 
                 1.2 
               
               
                   
                 V337Q 
                 0.9 
               
               
                   
                 V337D 
                 0.5 
               
               
                   
                 V337M 
                 0.2 
               
               
                   
                 V337E 
                 0.2 
               
               
                   
                 V337G 
                 0.1 
               
               
                   
                 N338H 
                 0.4 
               
               
                   
                 Q339I 
                 1.1 
               
               
                   
                 Q339T 
                 0.3 
               
               
                   
                 Q339A 
                 0.1 
               
               
                   
                 N340S 
                 2.0 
               
               
                   
                 N340A 
                 0.2 
               
               
                   
                 N340C 
                 0.2 
               
               
                   
                 V342A 
                 1.2 
               
               
                   
                 V342L 
                 0.8 
               
               
                   
                 V342I 
                 0.5 
               
               
                   
                 V342R 
                 0.2 
               
               
                   
                 V342D 
                 0.2 
               
               
                   
                 L343C 
                 1.3 
               
               
                   
                 L343Q 
                 1.2 
               
               
                   
                 L343I 
                 1.0 
               
               
                   
                 L343A 
                 0.9 
               
               
                   
                 L343P 
                 0.8 
               
               
                   
                 L343S 
                 0.8 
               
               
                   
                 L343D 
                 0.8 
               
               
                   
                 L343Y 
                 0.5 
               
               
                   
                 L343F 
                 0.5 
               
               
                   
                 L343K 
                 0.4 
               
               
                   
                 L343H 
                 0.3 
               
               
                   
                 L343E 
                 0.3 
               
               
                   
                 L343N 
                 0.2 
               
               
                   
                 Q344I 
                 1.7 
               
               
                   
                 Q344R 
                 0.8 
               
               
                   
                 Q344S 
                 0.6 
               
               
                   
                 N345C 
                 1.1 
               
               
                   
                 N345A 
                 1.0 
               
               
                   
                 N345H 
                 1.0 
               
               
                   
                 N345W 
                 0.9 
               
               
                   
                 N345Q 
                 0.8 
               
               
                   
                 N345R 
                 0.6 
               
               
                   
                 N345I 
                 0.4 
               
               
                   
                 N345V 
                 0.3 
               
               
                   
                 N345P 
                 0.2 
               
               
                   
                 G346H 
                 0.2 
               
               
                   
                 S347R 
                 1.3 
               
               
                   
                 S347H 
                 1.2 
               
               
                   
                 S347I 
                 0.8 
               
               
                   
                 S347A 
                 0.7 
               
               
                   
                 S347G 
                 0.6 
               
               
                   
                 S347K 
                 0.5 
               
               
                   
                 S347Y 
                 0.5 
               
               
                   
                 S347W 
                 0.4 
               
               
                   
                 S347T 
                 0.2 
               
               
                   
                 S347L 
                 0.2 
               
               
                   
                 S347F 
                 0.1 
               
               
                   
                 S349R 
                 0.8 
               
               
                   
                 S349C 
                 0.7 
               
               
                   
                 S349A 
                 0.6 
               
               
                   
                 S349V 
                 0.6 
               
               
                   
                 S349I 
                 0.4 
               
               
                   
                 S349F 
                 0.4 
               
               
                   
                 S349Y 
                 0.4 
               
               
                   
                 S349T 
                 0.4 
               
               
                   
                 S349M 
                 0.2 
               
               
                   
                 S349D 
                 0.1 
               
               
                   
                 N350K 
                 0.6 
               
               
                   
                 N350A 
                 0.5 
               
               
                   
                 W354L 
                 0.7 
               
               
                   
                 S357V 
                 1.7 
               
               
                   
                 S357Q 
                 0.4 
               
               
                   
                 S359H 
                 1.7 
               
               
                   
                 S359Q 
                 1.5 
               
               
                   
                 S359F 
                 1.1 
               
               
                   
                 S359R 
                 0.8 
               
               
                   
                 S359I 
                 0.8 
               
               
                   
                 S359G 
                 0.7 
               
               
                   
                 S359Y 
                 0.6 
               
               
                   
                 S359A 
                 0.6 
               
               
                   
                 S359P 
                 0.6 
               
               
                   
                 S359N 
                 0.5 
               
               
                   
                 S359W 
                 0.4 
               
               
                   
                 S359E 
                 0.2 
               
               
                   
                 S360R 
                 0.6 
               
               
                   
                 S360G 
                 0.2 
               
               
                   
                 Q363V 
                 1.2 
               
               
                   
                 Q363R 
                 0.9 
               
               
                   
                 Q363A 
                 0.9 
               
               
                   
                 Q363G 
                 0.8 
               
               
                   
                 Q363H 
                 0.5 
               
               
                   
                 Q363L 
                 0.3 
               
               
                   
                 Q363N 
                 0.3 
               
               
                   
                 Q363F 
                 0.2 
               
               
                   
                 P364Q 
                 0.8 
               
               
                   
                 P364H 
                 0.7 
               
               
                   
                 P364W 
                 0.3 
               
               
                   
                 P364I 
                 0.2 
               
               
                   
                 P364L 
                 0.1 
               
               
                   
                 T366S 
                 2.0 
               
               
                   
                 T366N 
                 1.2 
               
               
                   
                 T366W 
                 1.1 
               
               
                   
                 T366Q 
                 1.0 
               
               
                   
                 T366C 
                 0.8 
               
               
                   
                 T366V 
                 0.7 
               
               
                   
                 T366A 
                 0.6 
               
               
                   
                 T366S 
                 0.4 
               
               
                   
                 T366L 
                 0.4 
               
               
                   
                 T366K 
                 0.3 
               
               
                   
                 T366R 
                 0.3 
               
               
                   
                 T366G 
                 0.2 
               
               
                   
                 T366I 
                 0.2 
               
               
                   
                 T366Q 
                 0.2 
               
               
                   
                 N367Y 
                 1.2 
               
               
                   
                 N367P 
                 0.9 
               
               
                   
                 N367L 
                 0.8 
               
               
                   
                 N367A 
                 0.7 
               
               
                   
                 N367F 
                 0.6 
               
               
                   
                 N367Q 
                 0.3 
               
               
                   
                 N367W 
                 0.2 
               
               
                   
                 N367D 
                 0.2 
               
               
                   
                 N367E 
                 0.2 
               
               
                   
                 L368D 
                 1.5 
               
               
                   
                 L368H 
                 0.6 
               
               
                   
                 S371F 
                 1.6 
               
               
                   
                 S371W 
                 1.3 
               
               
                   
                 S371V 
                 1.1 
               
               
                   
                 S371E 
                 0.6 
               
               
                   
                 S371R 
                 0.3 
               
               
                   
                 S371H 
                 0.3 
               
               
                   
                 S371Q 
                 0.3 
               
               
                   
                 S371D 
                 0.2 
               
               
                   
                 S371I 
                 0.2 
               
               
                   
                 N373D 
                 1.3 
               
               
                   
                 N373I 
                 1.1 
               
               
                   
                 N373E 
                 1.1 
               
               
                   
                 N373W 
                 0.7 
               
               
                   
                 N373Y 
                 0.5 
               
               
                   
                 N373A 
                 0.4 
               
               
                   
                 N373H 
                 0.4 
               
               
                   
                 N373Q 
                 0.2 
               
               
                   
                 H374E 
                 1.4 
               
               
                   
                 H374F 
                 1.3 
               
               
                   
                 H374D 
                 0.7 
               
               
                   
                 H374T 
                 0.5 
               
               
                   
                 H374S 
                 0.4 
               
               
                   
                 H374I 
                 0.3 
               
               
                   
                 H374L 
                 0.3 
               
               
                   
                 H374W 
                 0.2 
               
               
                   
                 W376A 
                 1.6 
               
               
                   
                 W376Q 
                 1.2 
               
               
                   
                 W376D 
                 1.1 
               
               
                   
                 W376M 
                 1.1 
               
               
                   
                 W376N 
                 0.9 
               
               
                   
                 W376P 
                 0.6 
               
               
                   
                 W376H 
                 0.5 
               
               
                   
                 W376Y 
                 0.5 
               
               
                   
                 W376L 
                 0.4 
               
               
                   
                 W376E 
                 0.3 
               
               
                   
                 W376G 
                 0.2 
               
               
                   
                 W376F 
                 0.2 
               
               
                   
                 W376R 
                 0.1 
               
               
                   
                 A377I 
                 0.8 
               
               
                   
                 A377V 
                 0.4 
               
               
                   
                 A377M 
                 0.2 
               
               
                   
                 H378A 
                 1.7 
               
               
                   
                 H378T 
                 1.5 
               
               
                   
                 H378I 
                 1.3 
               
               
                   
                 H378R 
                 1.3 
               
               
                   
                 H378C 
                 1.3 
               
               
                   
                 H378M 
                 1.1 
               
               
                   
                 H378Q 
                 1.0 
               
               
                   
                 H378N 
                 1.0 
               
               
                   
                 H378G 
                 0.9 
               
               
                   
                 H378L 
                 0.9 
               
               
                   
                 H378V 
                 0.9 
               
               
                   
                 H378S 
                 0.8 
               
               
                   
                 H378Y 
                 0.6 
               
               
                   
                 H378K 
                 0.5 
               
               
                   
                 H378D 
                 0.4 
               
               
                   
                 H378P 
                 0.4 
               
               
                   
                 H378E 
                 0.3 
               
               
                   
                 H378F 
                 0.2 
               
               
                   
                 P380M 
                 1.8 
               
               
                   
                 P380D 
                 1.6 
               
               
                   
                 P380E 
                 1.4 
               
               
                   
                 P380C 
                 1.3 
               
               
                   
                 P380V 
                 1.3 
               
               
                   
                 P380I 
                 1.2 
               
               
                   
                 P380L 
                 1.2 
               
               
                   
                 P380F 
                 0.8 
               
               
                   
                 P380G 
                 0.8 
               
               
                   
                 P380K 
                 0.3 
               
               
                   
                 P380H 
                 0.3 
               
               
                   
                 T385F 
                 0.7 
               
               
                   
                 T385M 
                 0.7 
               
               
                   
                 T385R 
                 0.2 
               
               
                   
                 V388E 
                 1.1 
               
               
                   
                 V388D 
                 1.1 
               
               
                   
                 V388Y 
                 0.9 
               
               
                   
                 V388K 
                 0.8 
               
               
                   
                 V388H 
                 0.4 
               
               
                   
                 V388L 
                 0.2 
               
               
                   
                 V388Q 
                 0.2 
               
               
                   
                 N390R 
                 0.6 
               
               
                   
                 N390M 
                 0.5 
               
               
                   
                 N390P 
                 0.3 
               
               
                   
                 R391C 
                 1.0 
               
               
                   
                 R391M 
                 0.8 
               
               
                   
                 R391G 
                 0.7 
               
               
                   
                 R391P 
                 0.7 
               
               
                   
                 R391H 
                 0.4 
               
               
                   
                 R391V 
                 0.3 
               
               
                   
                   
               
            
           
         
       
     
     The results show that the xylanase variants have improved thermostability relative to the wild-type xylanase (SEQ ID NO: 1). 
     Example 3: Animal Feed and Animal Feed Additives 
     Granule 
     The granule is prepared by granulating a xylanase variant of the invention with a filler such as sodium sulfate, magnesium sulfate, calcium carbonate and/or cellulose and then optionally coating the granule with a wax coating (e.g. hydrogenated palm oil) or a salt coating (e. g. sodium sulfate and/or magnesium sulfate). 
     Alternatively, granule is prepared by absorbing a liquid solution of a xylanase variant of the invention onto an inert core and then optionally coating the granule with a wax coating (e.g. hydrogenated palm oil) or a salt coating (e. g. sodium sulfate and/or magnesium sulfate). 
     Animal Feed Additive 
     A premix formulation of a xylanase variant of the invention containing 0.01 g to 10 g enzyme protein per kilo of premix (optionally formulated as a coated granule) is added to the following premix: 
     
       
         
           
               
               
               
             
               
                   
               
             
            
               
                 5000000 
                 IE 
                 Vitamin A 
               
               
                 1000000 
                 IE 
                 Vitamin D3 
               
               
                 13333 
                 mg 
                 Vitamin E 
               
               
                 1000 
                 mg 
                 Vitamin K3 
               
               
                 750 
                 mg 
                 Vitamin B1 
               
               
                 2500 
                 mg 
                 Vitamin B2 
               
               
                 1500 
                 mg 
                 Vitamin B6 
               
               
                 7666 
                 mcg 
                 Vitamin B12 
               
               
                 12333 
                 mg 
                 Niacin 
               
               
                 33333 
                 mcg 
                 Biotin 
               
               
                 300 
                 mg 
                 Folic Acid 
               
               
                 3000 
                 mg 
                 Ca-D-Panthothenate 
               
               
                 1666 
                 mg 
                 Cu 
               
               
                 16666 
                 mg 
                 Fe 
               
               
                 16666 
                 mg 
                 Zn 
               
               
                 23333 
                 mg 
                 Mn 
               
               
                 133 
                 mg 
                 Co 
               
               
                 66 
                 mg 
                 I 
               
               
                 66 
                 mg 
                 Se 
               
               
                 5.8 
                 % 
                 Calcium 
               
               
                  25 
                 % 
                 Sodium 
               
               
                   
               
            
           
         
       
     
     Animal Feed 
     This is an example of an animal feed (broiler feed) comprising the animal feed additive as described above: 
     62.55% Maize 
     33.8% Soybean meal (50% crude protein) 
     1.0% Soybean oil 
     0.2% DL-Methionine 
     0.22% DCP (dicalcium phosphate) 
     0.76% CaCO 3  (calcium carbonate) 
     0.32% Sand 
     0.15% NaCl (sodium chloride) 
     1% of the above Premix 
     The ingredients are mixed, and the feed is pelleted at the desired temperature, e.g. 60, 65, 75, 80, 85, 90 or even 95° C. 
     Liquid Formulation 
     A liquid formulation of a xylanase variant of the invention comprises 0.1% to 10 w/w enzyme protein, 40-60% glycerol, 0.1 to 0.5% sodium benzoate and water. The liquid formulation is sprayed onto the pelleted animal feed described above (in this case the animal feed additive would not include the xylanase variant of the invention present). 
     The invention described and claimed herein is not to be limited in scope by the specific aspects herein disclosed, since these aspects are intended as illustrations of several aspects of the invention. Any equivalent aspects are intended to be within the scope of this invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. In the case of conflict, the present disclosure including definitions will control.