bluuebunny/crossref_metadata_2025_split huggingface dataset:
Granulation of digested sewage sludge in mesophilic UASB reactors treating distillery waste waters from sugar cane molasses
Authors: Ramos J. , Obaya M. C. , Valdes E. , Villa P. , Eng F. 
Published: December 2004

AbstractFive 4.02‐1 UASB (Upflow Anaerobic Sludge Blanket) reactors were continuously operated at 30°C under different hydrodynamic regimes for more than 120 days. The effect of the upflow liquid velocity (ULV) over the range of 0.25 to 2.0 m/h on the biological characteristics of the granules formed by treating vinasses (waste water of alcohol distilleries) from sugar cane molasses was investigated constantly maintaining the volumetric loading rate (VLR) (8 g COD/l · d). Granular sludge was found at all the ULV tested. The size, shape, etc., of the granules indicated that the ULV had a considerable effect on the sludge cultivated in this type of system, thereby acting as a selection process for the biomass. The best results in relation to the time of appearance, size, shape, consistence, stability, composition, and the accumulation were observed in the ULV range between 0.25 and 0.5 m/h.Microscopic studies of the granules using optical and epifluorescence microscopes and the scanning electron micrograph (SEM) showed a heterogeneous biomass and revealed the cell characteristics.
Monoterpenol glycosides in plants and their biotechnological transformation
Authors: Vasserot Y. , Arnaud A. , Galzy P. 
Published: December 2004

AbstractThe present paper reviews the different monoterpenols and monoterpene polyols identified in the glycoside form in the plant kingdom. The glycosidic moieties involved are also considered. The natural pathways for the synthesis and hydrolysis of these monoterpene glycosides and the different hypothesis concerning their metabolism are discussed. The present state of different projects for the biotechnological transformation of these aromatic precursor compounds is reported.
Fermentation kinetics of free and immobilized Penicillium raistrickii able perform the 15α‐hydroxylation of 13‐ethyl‐gon‐4‐ene‐3,17‐dione
Authors: Schlosser D. , Irrgang S. , Schmauder H.‐P. 
Published: December 2004

AbstractGrowing Penicillium raistrickii i 477 cells immobilized by microencapsulation, entrapment in calcium alginate beads and photopolymerization were used for the 15α‐hydroxylation of 13‐ethyl‐gon‐4‐en‐3,17‐dione (I) to 15α‐hydroxy‐13‐ethyl‐gon‐4‐en‐3,17‐dione (II). The immobilized cells had lower maximum specific growth rates and yield coefficients when cultivated on the carbon source glucose than the non‐immobilized cells, which leads to lower volumetric productivities than the use of nonimmobilized cells. However, the cells immobilized by microencapsulation and calcium alginate entrapment showed a specific productivity equal to that of the respective non‐immobilized cells based on product formation per dry biomass and time. Photommobilized cells were not able to grow in the presence of the steroid because the substrate concentrations within the polymer reached inhibiting amounts for growth and product formation. In the absence of the steroid, the growing photoimmobilized cells showed a prolonged lag‐phase in comparison with the free cells.
The effects of xylanase type enzymes on the different layers of birch wood ORGANOSOLV pulp fibre walls
Authors: Leite M. , Eremeeva T. , Treimanis A. , Egle V. , Bykova T. , Purina L. , Viesturs U. 
Published: December 2004

AbstractSome effects of the xylanase treatment on the separate birch ORGANOSOLV pulp fibre wall morphological layers were examined. These investigations were focused on the outer layers, i.e. the primary wall (P) and the outer layer of the secondary wall (S1), as well as the central layers, i.e. the central layer of the secondary wall (S2) and the tertiary wall (T). Step by step, the fractionation of the pulp components in the polar solvents N,N‐dimethylformamide (DMFA), dimethylsulphoxide (DMSO) and DMSO/H3PO4 was used as a mild technique for the isolation of the lignin‐carbohydrate complexes. The different residual amounts of lignin and hemicelluloses in the outer and central pulp fibre wall layers as well as the different lignin‐hemicellulose ratios were determined. The size‐exclusion chromatographical (SEC) analysis showed a higher initial lignin content in the region of the high molecular mass (MM) fibre wall fraction extracted with “DMSO/H3PO4” than the outer cell wall layers. In the central layers, the amounts of soluble lignin (calculated on the mass of total dissolved substance) were approximately the same for all the three solvents.The xylanase treatment brought the most considerable changes in the high MM part of the residual lignin (the lignin carbohydrate complex). This was true for both the P‐S1 and S2‐T layers. The careful brightness comparison of the outer and central fractions after the X‐E‐P‐P bleaching sequence showed a surprisingly low bleachability of the outer layer fraction. The xylanase action depended on the composition of the lignin‐carbohydrate complex (LCC) and the extent of the maintenance of the outer layers during the pulping process.
Characterization of casein peptones by HPLC profiles and microbiological growth parameters
Authors: Reissbrodt R. , Beer W. , Claus H. , Müller R. 
Published: December 2004

AbstractThirty six pancreatic casein peptones from various producers were analyzed by HPLC and by microbiological growth tests. The data were compared by using the principal coordinate analysis and simple mathematical tests. The Proteose peptone quotient, PQ1, determined by the growth of Escherichia coli, separated these casein peptones into three groups, depending on their suitability as nutrients compared to Proteose peptone as a standard. These groups corresponded to the HPLC patterns, characterized by the specific peaks of polypeptides, peptides and amino acids, respectively. The peaks of the high‐molecular weight polypeptides were negatively correlated with the growth parameters. The peptides of a low molecular weight promoted the growth of Staphylococcus aureus with and without the exhaustion of usable N compounds and in the presence and absence of glucose (PQ2 and PQ3). The colony sizes correlated weakly with certain peaks only. HPLC patterns, thus, seem to be useful for the characterization of casein peptones for the standardization of nutrient media as well as for special applications.
Production of rifamycin B and SV by free and immobilized cells of Amycolatopsis mediterranei
Authors: Farid M. A. , El‐Diwany A. I. , El‐Enshasy H. A. , Abu‐Shady M. R. 
Published: December 2004

AbstractThe effect of growth conditions (incubation time, inoculum size, initial pH value) and some nutrient concentrations on the growth and rifamycin B and SV production by free and immobilized cells of Amycolatopsis mediterranei CBS 42 575 was studied. In alginate beads, the immobilized cells behaved like the free cells, but a pronounced difference was observed in antibiotic production and cell growth. The rifamycin production by the immobilized cells was higher than that obtained by the free cells. The immobilized cells were also reused repeatedly for six batch cultivations with a fresh medium charged into flasks at the beginning of each batch. It was found that the immobilized cells were stable, and the rifamycin yield was almost constant during the first three batches and then decreased.
Physiological restriction of the L‐lactic acid production by Rhizopus arrhizus
Authors: Rosenberg M. , Krišofíková L. 
Published: December 2004

AbstractThe influence of basic physiological factors on the quality of inocula and L(+)‐lactic acid production by Rhizopus arrhizus CCM 81 09 were studied.The most effective preparation of the spores (5 × 107 spores/ml) and subsequent good lactate production was achieved on the agar medium with soil extract and malt agar. The optimum initial amount of active spores for inoculation was 103–104 spores/ml. The preparation of inoculum required intensive stirring with lower aeration and pH maintained in the range from 4.8 to 6.0 by the addition of CaCO3. The maximum yield of lactic acid production was achieved by using 5% (v/v) of 24‐h‐old inoculum. The intensity of lactic acid production in the inoculum was proportional to its production in the subsequent steps of fermentation and can be used as a fast control of the physiological state of the producers.
A new version of an in situ sampling system for bioprocess analysis
Authors: Hilmer J.‐M. , Scheper Th. 
Published: December 2004

AbstractIn this article, attention is focussed on an on‐line sampling device for bioreactors and its characterization regarding sterility and response time. The integration of this device into analytical systems for biotechnology (FIA with biosensors) resulted in on‐line analysis systems for bioprocess control. The new ESIP version of an in situ sampling system for bioprocess analysis produced by the EPPENDORF‐NETHELER‐HINZ GmbH, Germany, had a short response time of 8 min (99%), which was determined by means of conductivity measurement after an increase of the medium conductivity due to the gradual addition of KCl. Effectiveness and reliability of the module were tested by bubble point measurement resulting in a bubble point pressure of 2.1 bars. The sampling probe was tested successfully for use in a broad variety of microorganisms and cultivations.
Penicillium citrinum protoplasts: Preparation, regeneration and lipolytic activity of regenerants
Authors: Maliszewska I. H. , Zboińska E. M. 
Published: December 2004

AbstractThe conditions for an optimum formation of protoplasts from mycelium of Pencillium citrinum, which produces extracellular lipase, were examined. The best results were achieved using Novozyme 234 in combination with β‐glucuronidase. Chitinase or β‐glucuronidase alone were not able to produce protoplasts under the given conditions. For the regeneration frequency, the type of osmotic stabilizer was important. The highest regeneration frequency (84.6% protoplasts) was achieved by using 0.6 M KCl as an osmotic stabilizer. Some regenerants were more effective in producing lipase than the parent. In particular, strain no. P‐8 showed a three times higher lipolytic activity than the parent strain, but this high enzyme activity was unstable after subculture.
Relationship between citric acid and extracellular acid phosphatase production by Aspergillus niger
Authors: Fiedurek J. , Pluta B. , Szczodrak J. , Jamroz J. 
Published: December 2004

AbstractOptimum conditions for citric acid production by Aspergillus niger in submerged culture were established. Some correlation was found between the ability of the fungus to produce citric acid and its capability to accumulate extracellular acid phosphatase. Mutagenization and passage on sodium citrate (10–25%) medium gave rise to eleven A. niger strains able to grow when the concentration was 25%. Two mutants showed an increase in citric acid production (8.8–25.7%), accompanied by the highest activity of acid phosphatase (43.1–46.6%).
Substrate specificity of laccase from Lentinus edodes
Authors: D'Annibale A. , Celletti D. , Felici M. , Di Mattia E. , Giovannozzi‐Sermanni G. 
Published: December 2004

AbstractIn previous studies, the white‐rot basidiomycete Lentinus edodes, strain SC‐495, was proved to be a “selective” lignin degrader and its extracellular crude preparations arising from solid‐state cultures were successfully employed in biopulping experiments on annual plants. This fungus produced extracellular laccase as the predominant phenoloxidase when growing in solid‐state fermentation on corn stalks. Laccase from this strain was purified and partially characterized, as an initial approach towards the study of its ligninolytic complex. Laccase was purified 69.6‐fold by anion‐exchange chromatography and two affinity‐chromatography steps with an overall yield of 7.45%. The native enzyme exhibited a molecular mass of 74 kDa, an isoelectric point of 3.42 and a carbohydrate content of 7.5%. The absorption spectrum of laccase showed a maximum at 605 nm, typical of blue‐copper oxidases. The optimum pH and temperature for the activity of laccase were 4.0–4.2 and 50°C, respectively. Kinetic experiments, performed with a wide range of phenolic compounds, showed that the reaction rate and the substrate affinity greatly varied depending on the nature of substituents and their reciprocal positions on the aromatic ring. In particular, the enzyme showed high affinity to phenolic compounds bearing methoxyl or methyl groups, but no affinity to those bearing the nitro group directly attached to the benzene ring, nor to non‐phenolic lignin‐related compounds, such as trans‐cinnamic acid or 3,4‐dimethoxycinnamic acid. The huge differences in terms of reactivity of the enzyme towards phenolic compounds suggests that a preliminary systematic screening should be advisable when using laccase in effluent treatment applications.
Application of statistical selection procedures for selecting the mutant with the highest enzyme activity from a set of mutants of the species Aspergillus niger
Authors: Römisch U. , Gargova S. 
Published: December 2004

AbstractThe enzyme Glucoamylase [1,4‐α‐D‐glucan‐glucohydrolase EC 3.2.1.3] is very important for the food industry. It is used for producing glucose, ethanol and beer, as well as in technological processes that require the decomposition of starch. Eight mutants of the species Aspergillus niger are evaluated and tested with respect to their production of Glucoamylase and proved to be suitable. The task is to find the mutant showing the highest enzyme activity with a given precision. Conventionally, this kind of multiple decision problem is handled by the analysis of variance (Model I), which tests the homogeneity of the population means, but in this case the results do not supply the desired information. Provided that the enzyme activities of the mutants are different, selection procedures can be used to choose the mutant with the “best” or at least a “good” level of activity.In this paper, a short methodical summary about the two classes of selection procedures is given, i.e. the indifference zone (and d‐correct) procedures and the subset procedures. By the example of the selection of a mutant with high enzyme activity the planning of experiments is shown. Depending on suppositions about the variances, different selection rules are applied. Starting with the subset procedure of GUPTA, the number of mutants is reduced to seven. The following application of the d‐correct procedures of BECHHOFER, DUNNETT and SOBEL allow us to calculate the necessary sample size of n = 49. Then the mutant whose sample has the largest mean will be selected as a “good” one with a given precision of d = 4 [u/l] and a probability of correct selection of (1–β) = 0.9This application is result of a cooperation between the Dept. of Food of the Technical University, Berlin, and the Dept. of Biotechnology of the Higher Institute of Food and Flavour Industry, Plovdiv, sponsored by the DAAD andthe TU Berlin.
Characteristics of a microbial assay for the detection of halogenated hydrocarbons using cells of an actinomycete‐like organism as a biological component
Authors: Peter J. , Buchinger W. , Karner F. , Hampel W. 
Published: December 2004

AbstractCells of an Actinomycete‐like bacterium, strain GJ70, with the ability to degrade several haloalkanes were used as a biological component in a discontinuous microbial bioassay for the detection of 1,3‐dichloropropene and 1,2‐dibromoethane in water. The cells were entrapped in different matrices such as calcium alginate, carrageenan, chitosan, polyacrylamide‐hydrazide and chitosan‐carboxy‐methyl cellulose; the specific dehalogenating activity of the immobilized cells to a stirred sample solution and by the use of an ion selective electrode (ISE) for the quantification of enzymatically released halogen ions, the concentration of halogenated hydrocarbons could be estimated by determining the change of electrode potential within a period of 5 min. The detection limits for 1,3‐dichloropropene and 1,2‐dibromoethane were below 100 μg/l and 25 μg/l, respectively; the relative standard deviation was < 10%. In addition, several chlorinated and brominated hgydrocarbons were converted by the bacterial cells at a reduced rate e.g. 1, 2‐dibromopropane, 1‐bromoethane, 1,5‐dichloropentane, etc. Moreover, temperatures of between 20 and 40%C did not affect the enzymatic activity of the cells, and a pH of between at 5 and 9 had little influence. Several organic substances and non‐metabolizable compounds did not affect the conversion, whereas some heavy metal ions acted as inhibitors.
Levan production by Zymomonas mobilis cells. Attached to plaited spheres
Authors: Bekers M. , Ventina E. , Laukevics J. , Kaminska E. , Upite D. , Vigants A. 
Published: December 2004

AbstractIn this work, an immobilization method for polymer‐levan production by a non‐flocculating Z mobilis culture was developed. The extent of cell attachment to the stainless steel wire surface, culture growth and product synthesis were described. It was established that during short‐term passive immobilization of non‐flocculation Z mobilis cells on a stainless steel wire surface, sufficient amounts of biomass for proper levan and ethano fermentation could not be obtained. Adherence of cells was improved by pressing the paste‐like biomass within stainless steel spheres knitted from wire with subsequent dehydration. Biomass fixed in metal spheres was used for repeated batch fermentation of levan. The activation period of cells within wire spheres (WS) was 48 h in duration. During this time, cell growth stabilized at production levels of ethanol and levan of Qeth = 1.238 g/l × h and qeth = 0.47 g/l × h; Qeth = 0.526 g/l × h and qeth = 0.20 g/l × h. Five stable fermentation cycles were realized using one wire sphere inoculum, and maintaining a stable ratio of 2.4 of biomass suspended in the medium to biomass fixed in the sphere. Using fixed Z mobilis biomass in the WS, the total amount of inoculum could be reduced for batch fermentation. Large plaited wire spheres with biomass may have potential in fermentation in viscous systems, including levan production.
Growth of Paenibacillus larvae, the causative agent of American foulbrood in honey bees and Bacillus popilliae, the causative agent of milky disease in beetle larvae in lepidopteran cell cultures
Authors: Steinkraus K. H. , Mortlock R. P. , Granados R. R. , McKenna K. A. , Villani M. G. , Robbins P. S. 
Published: December 2004

AbstractTNM‐FH Lepidopteran insect cell culture medium containing 10% fetal bovine serum (FBS), while allowing limited vegetative growth of Paenibacillus larvae (wild‐type strain), the causative agent of American foulbrood, contained no viable vegetative cells upon subculture, nor were any heat resistant spores produced in this medium alone. However, TNM‐FH medium cotaining embryonic or midgut cells from Trichoplusia ni, hemocytes from Estigmene acrea, ovarian and embryonic cells from Spodoptera frugiperda, embryonic cells from Plutella xylostella, Spodoptera exigua and Pseudaletia unipuncta or ovarian cells from Lymantria dispar, supported both heavy vegetative cell growth and moderate production of heat resistant spores. EX‐CELL 405 serum‐free insect cell culture medium alone appeared to contain the appropriate nutrients required for both vegetative growth and sporulation of P. larvae. However, in the presence of embryonic cells from T. ni, limited vegetative growth occurred and the P. larvae cells appeared to die off. This was confirmed by the fact that no colony growth occurred upon subculture, nor were any heat resistant spores detected. This was true also in the presence of fat body cells from T. ni, except that a limited number of spores (4,000/ml) were detected in the form of cology‐forming units (CFU) on plates following heating to 80°C for 20 minutes. In a parallel study with a wild‐type strain of Bacillus popilliae, vegetative cells grew only in TNM‐FH medium in the presence of mid‐gut BTI‐Tn‐MG and ovarian (Tn‐368) cells of T. ni. No heat resistant spores, however, were detected in any of the cultures. When BTI‐Tn‐MG and Tn‐368 cells were further challenged with four variant cultures of B. popilliae, vegetative growth and limited sporulation were achieved. The BTI‐Tn‐MG cell line in TNM‐FH medium produced as many as 12,000 spores/ml after 21 days in culture.
Influence of some physicochemical factors on the viscosity of aqueous levan solutions of Zymomonas mobilis
Authors: Vina I. , Karsakevich A. , Gonta S. , Linde R. , Bekers M. 
Published: December 2004

AbstractZymomonas mobilis strain 113 “S” produces levan – an extracellular, viscous, biologically active, non‐toxic fructose polymer with a unique structure and extraordinary properties. This polysaccharide was isolated at two different degrees of purity by alcohol precipitation from aqueous solutions and was characterized with respect to some rheological properties and stability of viscous solutions.The effects of temperature, pH and salt concentration on the viscosity of 1–3% levan solutions were examined. The viscosity of levan solutions was found to be quite stable and reversible at room temperature over a wide range of pH from 4 to 11. The viscosity was slightly affected by increased salt concentration. Levan solutions were rather stable at high temperatures (up to 70°C, 1 h, pH 6), where the viscosity could be almost completerly restored (up to 80–100%). Therefore, the degradation of the polymer structure under these conditions is probably insignificant. Temperatures of 70–100°C with a pH of less than 3.5 caused irreversible degradation of the levan structure.The above‐mentioned properties of levan, obtained from Zymomonas mobilis 113 “S”, demonstrated the potential for the development of various therapeutic forms of pharmacologically‐active levan and their application in medicine as well as in the food and other industries.
Characterization of microbial endo‐β‐glucanase immobilized in alginate beads
Authors: Busto M. D. , Ortega N. , Perez‐Mateos M. 
Published: December 2004

AbstractEndo‐β‐glucanase (endo‐β‐1,4‐glucano‐glucanase EC 3.2.1.4), isolated from Trichoderma reesei, was immobilized in calcium alginate beads, retaining 75% of its original activity. The polyanionic moiety surrounding the immobilized enzyme displaced the pH‐activity profile to alkaline regions with respect to that of the free enzyme. The enzyme was inhibited by carboxymethylcellulose, but this inhibition appeared to be decreased by immobilizatíon. The enzyme immobilized in alginate beads showed a Km value (1.02% w/v) lower than that of the enzyme (1.31%). The apparent Vmax of immobilized cellulase preparations (238.3 μmol glucose/ml × h) decreased by a factor of 0.59 with respect to that of the soluble enzyme. The optimum temperature (60°C) of the free and entrapped enzymes remained unaltered. In contrast, the half‐life of the endoglucanase immobilized in calciumalginate beads was 4.6 h at 55°C and 5.4 h at 60°C, while that of the free enzyme was 3.0 h at 55°C and 1.2 h at 60°C. A technological application of the immobilized enzymes was tested using wheat straw as a source of fermentable sugars. The hydrolytic degradation of straw, by means of a crude extract of free and immobilized cellulases and β‐glucosidase, released a large amount of reducing sugars from wheat straw after 48 h (between 250–720 mg glucose/g straw), carrying out more than a 90% saccharification. A mixture of immobilized β‐glucosidase and free cellulases maintained 80% of the activity of the soluble counterparts, and the co‐immobilization of both types of enzymes reduced by hydrolytic efficiency to half.