bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enzymes,D‐Amino Acid Oxidases
Authors: Pilone Mirella S. , Pollegioni Loredano 
Published: April 2010

AbstractThis article is an up‐to‐date report on the biotechnological applications in the industry of the flavoproteinD‐amino acid oxidase, in the past and in the present.D‐Amino acid oxidase constitutes a model FAD‐dependent protein due to widespread interest and extensive investigations in the years in mechanistic and structural research, on the basic features of flavin chemistry, reactivity, and their modulation by the protein moiety. Actually, a number of successful and unexpected outcomes came forD‐amino acid oxidase from biotechnology and their industrial applications: production of semi‐synthetic cephalosporin intermediates (as 7‐amino cephalosporanic acid, a milestone in the antibiotics industry), the resolution of racemic mixtures of amino acids (even unnatural ones), the analytical determination ofD‐amino acid content in biological samples by biosensors (including the determination ofD‐serine in brain cells), and a gene therapy for tumor treatment. All the biotechnological processes reported are described in detail, as well as the underlying technology. The most relevant patents are also reported.
Enzymes, Detergent
Authors: Maurer Karl‐Heinz 
Published: April 2010

AbstractEnzymes used in laundry and dish‐wash detergents represent one of the major application fields of enzymes. The hydrolases used in detergents are considered essential for removal of stains originating from nature. Some enzymes like cellulases do also contribute to antigraying effects by pigment removal and antiredeposition activity. Enzymes (proteases) were first introduced in laundry detergents at the end of the 1960s. Since then, they have become an important topic for product differentiation and performance claims. Thus the work on improving enzyme performance in terms of improved performance and stability in storage and process has become a major field of enzyme development. All relevant technologies for enzyme engineering have been applied in the meantime, resulting in a patent landscape of extreme complexity. In order to allow for efficient and economic production of technical enzymes, classical strain improvement has been combined with recombinant production systems early on.Detergent enzymes represent the only example of biocatalysis performed in a household setting. Since the potential for inhalation sensitization has been identified with detergent proteases on workers, the risk assessment both, for occupational as well as for the consumer setting has been a key topic that has been successfully managed since 1970.The upcoming field of synthetic biology promises to deliver further improvement of production systems and new enzymatic activities.
Enzyme‐Catalyzed Asymmetric Reduction of Ketones
Authors: Gröger Harald , Borchert Sonja , Kraußer Marina , Hummel Werner 
Published: April 2010

AbstractThe enantioselective transformation of a prochiral C=O double bond into the corresponding reduced CH–OH single bond plays a major role in asymmetric synthesis since this type of transformation represents a straightforward and an atom‐economical approach toward the synthesis of optically active alcohols. Owing to the importance of chiral alcohols in the field of chiral drug production, enantioselective ketone reduction also gained tremendous industrial interest. For the enantioselective reduction of ketones, numerous efficient catalytic routes have been developed up‐to‐date. As outstanding chemocatalytic technologies, metal‐catalyzed asymmetric hydrogenation of ketones and borane reduction are widely applied on industrial scale. Complementing these chemocatalytic technologies for the production of enantiomerically pure alcohols, enantioselective biocatalytic reduction of ketones turned out to be a highly efficient and competitive alternative technology. Notably, biocatalytic ketone technologies already made the “jump” from an interesting academic synthetic tool toward an industrially feasible technology platform. Besides high catalytic efficiency and excellent enantioselectivities, robustness and industrial large‐scale feasibility are further key features of enantioselective ketone reduction processes with biocatalysts. Thus, it is no surprise that the suitability for industrial purpose, in particular, for large‐scale manufacture of enantiomerically pure alcohols as drug intermediates, has been already demonstrated by a broad range of technical applications in the chemical and pharmaceutical industry.
Enzymes, Starch Conversion
Authors: Pedersen Sven 
Published: April 2010

Abstract
The enzymes used in starch processing are reviewed with emphasis on the conversion of starch to high fructose corn syrup (HFCS). Steeping is discussed as well as major developments in liquefaction, saccharification, and isomerization.
A major trend in starch processing today is the enzymatic production of slowly digestible and resistant starch for low calorie foods and foods for diabetics. Such starches may be produced by branching enzymes and amylomaltase. The properties of these enzymes and the production processes for the novel starches are described.
The production of glucose, maltose syrups, and maltodextrins amount worldwide to approximately 18 million tons and therefore represents a substantial segment of the use of starch. The production methods and the enzymes used for maltose syrups are summarized.
Recent references to important developments in enzymatic starch production are listed.
Enzymes, Extremely Thermophilic
Authors: Harris James M. , Adams Michael , Kelly Robert M. 
Published: April 2010

AbstractThe availability of enzymes with optimal functional temperatures above 70°C has had considerable impact on basic and applied elements of biocatalysis. Not only have extremely thermophilic enzymes expanded the known thermal range of biological systems but they have also ushered in a new era in applied biocatalysis that is less restricted by limitations related to thermoactivity and thermostability. While much effort has been directed at understanding the intrinsic basis for enzyme stabilization at high temperatures, there is still much to be learned to appreciate this complex biomolecular trait. Nonetheless, strategic uses of extremely thermophilic enzymes continue to emerge and prospects for expanded use of biocatalysts in a variety of bioprocess settings are promising. As genome sequence information from extremely thermophilic microorganisms is mined for novel biocatalysts and molecular biological tools for improving enzyme function are refined, the future is bright for biologically based catalysis.
Virus Retentive Filters
Authors: Miesegaes George , Lute Scott , Aranha Hazel , Brorson Kurt 
Published: April 2010

Abstract
Ensuring the absence of detectable viruses in biopharmaceutical products is imperative from both a regulatory and patient safety standpoint. Biopharmaceutical viral safety is the result of multiple orthogonal barriers operating in concert; incorporation of virus clearance methods is an important strategy to achieving product safety. Filtration through virus retentive filters is currently a key unit operation during the production of biopharmaceuticals and plasma‐derived products. Careful process design and appropriate validation are critical for the successful implementation and performance of virus retentive filters. Here we elaborate on both process design and validation information, describe virus filters currently on the market, and discuss the historical experience with virus retentive filters as reported in the scientific literature. Detailed information for filter users can be found in a comprehensive technical report (TR 41) promulgated by the Parenteral Drug Association (PDA) (1).
Flux Analysis of Mammalian Cell Culture
Authors: Martens Dirk E. , Tramper Johannes 
Published: April 2010

Abstract
Animal cells are used for the production of vaccines and pharmaceutical proteins. The increase in demand for these products requires an increase in volumetric productivity of animal cell culture processes, which can be attained through an increase in biomass concentration and/or specific productivity. At the same time, the correct glycosylation pattern must be preserved to guarantee the correct biological activity of the protein. To optimize the volumetric productivity and to keep the desired glycosylation pattern of the protein, knowledge of cell physiology including cell metabolism is essential.
The metabolism of animal cells is complex; because metabolism is distributed over different compartments, animal cells have complex nutritional demands and substantial waste metabolism occurs. Metabolic flux modeling can be a useful tool to reduce this complexity and to obtain a better understanding of cell metabolism. The models can be used to obtain fundamental understanding of metabolism, design media, and processes and for process control. For these applications, it would be useful to further develop genome‐scale models for mammalian cells.
In this article, first, the theory and concepts of metabolic flux analysis are treated using a simplified example of mammalian cell catabolism. Subjects that are discussed are as follows: model construction and simplification, methods to calculate fluxes, underdetermined systems, consistency testing, and rate balancing. Next, a comprehensive metabolic network model for mammalian cells is presented and specific problems associated with flux analysis in mammalian cells, such as the different underdetermined parts, are discussed. Finally, applications for metabolic network models in animal cell culture are briefly discussed.
Haploid Plant Production, Pollen, Anther, and Ovule Culture
Authors: Veilleux Richard E. 
Published: April 2010

AbstractHaploid plants with the gametic chromosome number can be obtained in many genera of angiosperms by redirection of gametophytic development to sporophytic development. This can be achievedin vitrothrough anther, microspore of ovule culture; alternatively, haploid plants can be obtainedin vivothrough parthenogenesis after wide hybridization, or occurring as one of a pair of twin seedlings. Doubled haploids can be derived from haploids by application of colchicine or through tissue culture regeneration from callus. The allelic simplicity of haploid plants or their corresponding doubled haploids facilitates genetic studies and hybrid breeding strategies. Doubled haploid cultivars of self‐pollinating crops, such as wheat and barley, have been released directly following field trials. For cross‐pollinating crops, doubled haploids have been used as parents of hybrid cultivars.
Immobilized Cells
Authors: Verica Manojlović , Branko Bugarski , Viktor Nedović 
Published: April 2010

AbstractCell immobilization consists of retaining living cells in a discrete spatial location to achieve high cell concentration. Immobilization of cells has been shown to offer many advantages for biomass and metabolite production when compared to free cell systems. Therefore, various types of living cells have been successfully immobilized for numerous applications. Different approaches have been used for immobilizing cells such as entrapment in polymeric networks, attachment or adsorption to a preformed carrier membrane, microencapsulation, and self‐aggregation of cells. A microcapsule consists of a semipermeable, spherical membrane surrounding the solid/liquid core. This review focuses on current knowledge and techniques used in the microencapsulation of cells to enhance their viability during processing or utilization in commercial products or targeted delivery. Further, the main process requirements, available carrier materials, and bioreactor designs aimed for successful implementation of immobilized cell technology will be summarized and discussed.
Kinetics, Enzymes
Authors: Cornish‐Bowden Athel 
Published: April 2010

AbstractThe kinetic behavior of enzymes is studied to elucidate mechanisms of action, to understand the role of enzymes in the cell, and to manipulate their activity in biotechnological applications. Most experiments are designed as if the only purpose was the elucidation of mechanisms, but the others are also important. Drug development not only requires thorough understanding of enzyme inhibition, and in particular that competitive inhibitors often have very little effect in a living system, but also that systems of enzymes often behave differently from what may be expected by studying them individually in isolation.
Kinetics, Microbial Growth
Authors: Panikov Nicolai S. 
Published: April 2010

AbstractThe article summarizes basic principles, methods, and the most essential results of kinetic studies in microbiology. Microbial kinetics is based on experimental studies of all dynamic manifestations of microbial life (growth, survival, death, product formation, mutations, cell cycles, environmental effects) and analysis of underlying mechanisms using mathematical models. The article starts from introduction to basic principles of growth stoichiometry (quantitative relationships between substrates and products of microbial processes) and enzyme kinetics and then, step‐by‐step surveys simple and structured models of microbial growth, cell cycle, mutation, and population dynamics. Special emphasis is given to similarity and difference in kinetic terms as applied to chemical reactions, enzyme‐catalyzed processes, and microbial growth. The last part of the chapter is devoted to characterization of diversity of cultivation methods including various continuous methods (chemostat, turbidostat, pH‐auxostat, viscostat, bistat), batch, fed‐batch, phased and dialysis culture, plug‐flow, columns packed, colonies and biofilms.
Lactonohydrolase
Authors: Shimizu Sakayu , Kataoka Michihiko 
Published: April 2010

AbstractThe enzyme catalyzing the reversible or irreversible hydrolysis of carboxylic esters into the corresponding carboxylic acids and alcohols plays an important role in the biosynthesis and biodegradation of various compounds. In particular, the structures and functions of lipase and esterase have been well analyzed. Lactonohydrolases also catalyze the hydrolysis of carboxylic esters, but act on the intramolecular ester bonds of the lactone compounds. They are involved in the synthesis and degradation of various lactone compoundsin vivo. Although the activities of lactonohydrolases have been detected in various organisms, there have not been any early detailed studies on their enzyme chemistry. In the last few decaded, several novel microbial lactonohydrolases were newly isolated and their application to bioprocesses for the production of useful compounds was examined.This articles deals with diveristy of lactonohydrolase, and their application to bioprocess technology.
Lipopolysaccharide,LPSremoval, Depyrogenation
Authors: Magalhães Pérola O. , Pessoa Adalberto 
Published: April 2010

AbstractAdvances in biotechnology have opened up numerous possibilities for the large‐scale production of many biomolecules that are important for research, pharmaceuticals, and industrial applications. The development of techniques and methods for the separation and purification of proteins and other biomolecules has been of paramount importance for many of these advances in the biotechnology industry. Such biomolecules may be expressed as soluble extracellular form, soluble intracellular form, or as membrane constitute or inclusion bodies. In all three cases, use of cellular rupture procedures for the recovery of the biomolecules of interest, which lead to the release of a large quantity of lipopolysaccharide (LPS)‐type endotoxins, is necessary. The presence of small amounts of endotoxin in recombinant protein preparations can cause side effects such as endotoxin shock, tissue injury, and even death in host organism. Owing to these reactions, research on the methods used to remove endotoxins from drugs, injectables, and other biological and pharmaceutical products is necessary. Taking into consideration the main techniques used as well as the state of the art of the technology in this field, the techniques of endotoxin determination and interaction of endotoxins with proteins are presented.
L
‐Malic Acid Production by Fumarase
Authors: Yonghong Hu , Pingkai Ouyang 
Published: April 2010

Abstract

Malic acid is an intermediate metabolite in the tricarboxylic acid cycle. It is widely used in pharmaceutical, food processing, and other industries. Malic acid was produced commercially by chemical synthesis or through fermentation processes that convert fumaric acid to
L
‐malic acid by using fumarase. In this article, we introduce several methods to produce
L
‐malic acid by fumarase.
Brevibacterium ammoniagenes
MA‐2 and
Brevibacterium flavum
MA‐3 were selected for producing fumarase. The fermentation results of these two strains showed that the internal‐loop airlift reactor was more suitable than the stirred reactor. In addition, a comparison of cell collection methods showed that flocculation and coagulation were more suitable. We also established several methods of cell immobilization using mixed gels, which were better than the conventional single κ‐Carrageenan entrapment. When the immobilized cells of
B. ammoniagenes
MA‐2 and
B. flavum
MA‐3 catalyzed the ammonia fumarate to
L
‐malic acid, the product concentrations were 210 g/L and 218 g/L respectively. Furthermore, the apparent kinetic parameters and the intrinsic kinetic parameters of immobilized cells were obtained. In order to cut down the residual fumaric acid, a conversion system was established to produce
L
‐malate coupling with immobilized
Escherichia coli
No. 1 cells for converting the remnant fumarate to
L
‐aspartic acid. A system‐integrated reaction and separation process, which produced
L
‐malic acid from free cells containing fumarase, was established. The yield was up to 99.9% under the optimum reaction conditions, giving us a satisfactory and economical result for industrial application. Finally, the mechanism for the system‐integrated reaction and separation process was studied.
Mammalian Cell Bioreactors
Authors: Zhou Weichang , Seth Gargi , Guardia Maria J. , Hu Wei‐Shou 
Published: April 2010

Abstract
Mammalian cells are widely used in the production of viral vaccines and therapeutic proteins. Most of those processes employ cells growing in suspension; however, some, especially those in vaccine production, use adherent cells. Stirred‐tank bioreactors are most widely used for mammalian cell culture processes. When a stirred‐tank bioreactor is used for growing adherent cells, a supporting surface for cell attachment is provided by the use of microcarriers or macroporous microcarriers. Alternatively, adherent cells are grown as aggregates in suspension. Fed‐batch culture is commonly practised since it reaches high cell and product concentrations. When a stirred‐tank bioreactor is operated in a continuous mode, it is a common practice to employ a cell retention device for perfusion in order to increase cell and product concentrations. As mammalian cell culture processes are increasingly being used in the manufacturing, one also witnesses an increasing adoption of disposable (or single‐use) cell culture devices. Traditional roller bottles are still often seen. Additionally, multiple flat plates or parallel trays, along with bag type cell growth chambers and even plastic stirred tanks, are used in moderate‐scale production and in the seed culture propagation for large‐scale bioreactors. Those disposable devices offer simplicity in operations and ease process validation in the production of biopharmaceuticals. Recently, some innovative bioreactors developed nearly two decades ago are finding applications in tissue engineering. Furthermore, the demand for high throughput operations in cell culture processing will continue to drive the innovations in bioreactor technology.
Membrane Chromatography
Authors: Pieracci John , Thömmes Jörg 
Published: April 2010

Abstract
It has been nearly 20 years since membrane chromatography was first introduced as a technology capable of purifying proteins. In that time, a large body of work has been generated which has described the fundamental transport mechanisms behind membrane adsorption, the advantages that membrane adsorbers possess as compared to column chromatography, the various membrane surface chemistries that can be created, and the application of membrane chromatography in the purification of a wide variety of proteins. In this review, the basic concept of membrane chromatography is explained, which includes a discussion of the factors that control membrane performance and how that performance can be optimized. The diverse ligand chemistries that have been used to create the three main families of membrane adsorbers that is affinity, hydrophobic interaction, and ion exchange, are described along with available membrane adsorber formats. Finally, applications of membrane adsorbers throughout a standard protein purification train, from the direct capture of proteins from unclarified feedstocks to the clearance of trace impurities in final polishing steps, will be demonstrated using small‐ and pilot‐scale examples.
Methanotrophs
Authors: Smith Thomas J. , Murrell J. Colin 
Published: April 2010

AbstractMethanotrophic bacteria have the unique ability to grow using methane as their sole source of carbon and energy. Methane monooxygenases (MMOs), which are the enzymes that catalyze the difficult reaction of methane with molecular oxygen, have the potential for upgrading of methane to the more valuable fuel methanol. MMOs, especially the catalytically versatile soluble MMO, can cooxidize a wide range of hydrocarbons and chlorinated hydrocarbons (including trichloroethylene) and much progress has been made toward their development as commercial catalysts for synthetic organic chemistry and bioremediation. The ability of methanotrophs to synthesize all organic cellular components from the simple hydrocarbon methane has led to a commercial process for making single‐cell protein (SCP) from methane. There have also been major developments toward their use as hosts for inexpensive production of recombinant proteins and valuable small molecules. Recent isolation of novel groups of methanotrophs has revealed a previously unknown diversity in their taxonomic origin and ability to thrive under extreme environmental conditions. We predict that genomic and postgenomic analysis of diverse methanotrophs and their enzymes will lead to new possibilities in biotechnology.
Methylotrophs, Industrial Applications
Authors: Leak David J. 
Published: April 2010

AbstractEarly investigations into the potential applications of methylotrophs focused mainly on the use of methane and methanol as cheap feedstocks for the production of single cell protein, and until recently this possibility was still being investigated. Despite the decline of this initial interest, the spin‐offs in terms of fundamental biochemical and genetic information, fermentation systems, and bioreactor design have opened up other avenues, either for products where substrate costs are paramount (e.g. amino acids), products originating from some of the unique features of C1metabolism (e.g. enzymes) or fortuitous discoveries (e.g. thePichia pastorisexpression system). After considering fundamental aspects of metabolism and energetics of methylotrophs and their implications for product formation, this review follows these subdivisions in turn, endeavoring to assess their future potential.