bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolierung von Cytochrom P‐450 und des entsprechenden Reductasesystems aus Acinetobacter calcoaceticus
Authors: Asperger O. , Müller R. , Kleber H.‐P. 
Published: December 2004

AbstractCytochrome P–450 is found in soluble as well as in particulate fractions of n‐alkane‐induced cells of Acinetobacter calcoaceticus EB 104 as shown by differential centrifugation and; gelfiltration experiments. It is reduced by NADH in the presence of at least two soluble proteins. Particulate cytochrome P–450 was extracted by Triton X‐100 and purified to homogeneity. The 80 fold enrichment resulted in a content of 19.0 nmol cytochrome P‐450/mg protein. The maxima of the absolute spectra are 417 nm for the oxidized, 408 nm for the reduced and 448 nm for the CO complex of reduced cytochrome. A ferredoxin, identified by maxima of 415 and 460 nm in the absorption spectrum of the oxidized form and by the occurrence of acid‐labile sulfur, as well as a corresponding NADH‐dependent ferredoxin reductase were isolated independently from the same bacterial strain. Enzymatic reduction of purified cytochrome P–450 is mediated by these proteins, which are discussed as in vivo components of the cytochrome P–450 system of A. calcoaceticus EB 104.
Einfluß von Kupfer‐, Mangan‐ und Zinkionen auf die makromolekulare Zusammensetzung der Hefe Candida utilis M 72
Authors: Schneider J. D. , Faulhaber E. , Ringpfeil M. 
Published: December 2004

AbstractThe ions of Cu2+, Zn2+ and Mn2+ affect significantly the macromolecular composition of yeast Candida uiilis M 72. Crude protein and nucleic acid content increase and carbohydrate content decreases with rising intracellular ion concentration. Lipid fraction is influenced by metallic ions only little.The correlation between intracellular ion concentration and cell composition of macromolecules can be described by simple equations.
Entwicklung von Berechnugsmodellen für Enzymreaktoren (Teil 2)
Authors: Setzermann U. , Vondran J. , Mohr K.‐H. 
Published: December 2004

AbstractBased on the partial differential equations for the transport of enthalpy and material a calculation model for the examination of the change of temperature and concentration in axial and radial direction was developed for the continuously working enzyme reactors. The pecularity of the kinetics of processes which are catalyzed by enzymes was considered due to the reaction velocity in modelling. In order to induce the numeric solution, an explicit method of differences was selected, the applicability of which was proved under consideration of appropriate initial and marginal conditions.
Laccase production by polyporus versicolor on different substrates
Authors: Sandhu D. K. , Arora D. S. 
Published: December 2004

AbstractExtracellular production of laccase (E.C. 1.10.3.2) by Polyporus versicolor was studied on lignin, complex and defined media. Although the production of enzyme was more on lignin the specific activity was more on malt extract. Laccase was produced on all the media tested i.e. phenolic compounds, lignins and sugars alone, and in combination with malt extract, excepting salicylic acid. On single source media maximum yields of enzyme were obtained on polyfon followed by resorcinol, reax and lignin. As compared to phenolic compounds the enzyme production was low on sugars. Addition of malt extract enhanced the enzyme yield which was maximum in the case of lignin followed by gallic acid.
Utilization of cellobiose and production of β‐clucosidase by nine yeast species
Authors: Sandhu D. K. , Mondal D. , Sidhu M. S. 
Published: December 2004

AbstractA comparative study of 9 yeasts namely, Candida blankii,C.humicola,C.ishiwadae,C.rhagii,C.tropicalis,Hensenula subpelliculosa,Saccharomyces cerevisiae,Trichosporon cutaneum and Tr.pullulans was carried out for the production of extracellular and cell bound β‐glucosidase using cellobiose as the substrate. Trichosporon cutaneum was found to be the best extracellular as well as cell bound β‐clucosidase producer and the former activity was more than the latter. In the rest of the yeasts most of them showed more cell bound β‐glucosidase as compared to the extracellular.
Mikrocomputer‐unterstützte prozeßkontrolle in der fermentationstechnik
Authors: Bayer K. 
Published: December 2004

AbstractNowadays computer control is an effective and well established tool in optimizing fermentation processes.Based on recent development in microelectronics, especially in the field of personal computers, cost effective applications of this technology are now possible, even on laboratory‐ and pilot scale. In this paper the application of a personal computer (CBM 3032), controlling various types of fermentations, is described.In more detail the availability of physiologically relevant sensors, especially the respiration and the dynamic calorimetry, are discussed.Finally some examples of practical realisations are presented.
Rechnergestützte Führung von fermentationsprozessen teil III
Authors: Prause M. , Schulz H.‐J. , Wagler D. 
Published: December 2004

AbstractIn the second part of the publication [1] the application of an adaptive algorithm for the adaptation of the static optimum was orientated on a specific problem.In this third part the indirect determination of the productivity from the nitrogen balance used in the adaptive algorithm is supplied, and control algorithms founded on the nitrogen balance are given in order to complete the algorithm.
Mikrobiologische Reaktionsabläufe beim AB‐Verfahren
Authors: Böhnke B. 
Published: December 2004

AbstractAt a comparable sludge loading of the second activation stage of the AB‐unit, in comparison with conventional one‐stage units for waste‐water cleaning, higher process stability and better quality outlet‐results are obtainedThese results could be confirmed both in pilot units and in industrial plańnts.
Fehlermöglichkeiten der Gelöstsauerstoffmessung beim Betrieb von Bioreaktoren
Authors: Stottmeister U. 
Published: December 2004

AbstractA review of errors, which can influence the measured data of electrochemical oxygen sensors (OS) in fermentation technique is presented.The specifities of various sensor constructions are pointed out. References are given for selection of sensors to application in fermenters. Influences on the measured values can take place by fermentation conditions, arrangement of sensors in the fermenter and composition of the fermentation broth. The oxygen measurement in the multi‐phase system of fermentation fluids can cause a remarkable deviation of the measured values to the real ones.Practical hints are given for use, calibration and sterilization of OS. Restricting conditions for measurements with this sensors are enumerated.
Kultivierung von isogenen E. coli‐Stämmen
Authors: Heinritz B. , Rogge G. , Ringpfeil M. 
Published: December 2004

AbstractThe strains E. coli C 600 and E. coli C 600 pL CR 665‐58 were cultivated on a glucose containing nutrient medium. The cell states of the cell cycle were investigated by means of phased cultivation. The doubling time and the specific carbon‐substrate consumption of cells were higher when E. coli C 600 pL CR 665‐58 was used. During cell doubling cell states characterized by different specific carbon‐substrate consumption coefficients were observed.By adaptation of carbon‐substrates supply to the repetitive cell states during continuous cultivation of synchronized bacteria populations the efficiency of cell‐mass production was increased by 15 percent.
Physiological adaption in the synthesis of the extracellular polysaccharide xanthan
Authors: Behrens U. , Fiedler S. , Stottmeister U. 
Published: December 2004

AbstractXanthan overproduction only takes place if a sugar which may serve as precursor is present and transition to limited growth occured. This transient phase is characterized by a change in composition of macromolecular cell components (RNA, protein, carbohydrates). During the transient phase nearly no nitrogen is consumed, whereas glucose and oxygen consumption proceeds nearly undisturbed. The changes observed in the transient phase are discussed in context with physiological adaption.
Autolysis in yeasts
Authors: Babayan T. L. , Bezrukov M. G. 
Published: December 2004

AbstractThe term “autolysis” was introduced into biological literature by SALKOVSKY [1]. Ever since it began to be used to designate self‐digestion of cells under the action of their own intracellular enzymes. This definition is sufficiently satisfactory with regard to bacteria, and there are published lots of original and review papers dealing specifically with bacteria. Considerably less material has been accumulated on eukaryotes, apparently due to the absence of the fact of the cell self‐digestion in most yeasts.
Influence of carbon dioxide solubility on the accuracy of measurements of carbon dioxide production rate by gas balance technique
Authors: Minkevich I. G. , Neubert M. 
Published: December 2004

AbstractThe total amount of carbon dioxide (CD) produced by a microbial culture is evolved via an outlet gas stream, outflowing broth, and can lead to a rise of the CD content in broth. To analyze relations among the three amounts, the equilibrium is considered between different ionic forms of carbon dioxide at different pH values as well as between the gaseous and disolved CO2. Dependences of the equilibrium constants on temperature are found by a thermodynamic analysis. Numerical estimation of an error of the CD production rate measurement, originating from the neglect of dissolved CD, is developed. The gas analysis technique alone provides a sufficient accuracy at pH lower than 6. At higher pH the error can be estimated using equations presented below.
Inhibierungserscheinungen bei der alkoholischen Gärung, II. Einfluß der Substratkonzentration auf die spezifische Ethanolbildungsgeschwindigkeit von Saccharomyees cerevisiae
Authors: Richter K. , Becker U. 
Published: December 2004

AbstractThe influence of sucrose concentration on the specific ethanol production rate was studied during batch processes using the yeast strain Saccharomyces cerevisiae Hansen Sc 5. From experimental data a model could be derived for the simulataneous effect of substrate and product inhibition. It was found that both the decreases of fermentation activity of the cells caused by sucrose and ethanol have an additional relation to each other. This model also takes into consideration the fact that the maximum ethanol concentration P′ can't be realized at high substrate concentrations in a batch process. Compared to it sucrose concentrations below 100 g/l did not inhibit the ethanol production by the strain used in this investigation.
Meßeinrichtung zur kontinuierlichen Bestimmung flüchtiger organischer Substanzen in wäßrigen Medien
Authors: Hanschmann G. , Geppert G. 
Published: December 2004

AbstractAfter a short review over methods for continuous determination of alcohols (methanol or ethanol) in fermentation liquids the working principle of a measuring device is described. With this apparatus preferentially low concentrations in the ppm‐range can be measured, but it is also suitable for higher concentrations without the necessity of sample dilution. Indication is linear over a wide range. Finally some experiences with the practical use of the instrument are given.
Wirkung von Ölen und Fettsäuren auf Wachstum und Enzymbildung bei Thermoactinomyees vulgaris. V. Untersuchungen zur Metabolisierung des Öles
Authors: Leuchtenberger A. , Ruttloff H. 
Published: December 2004

AbstractThe splitting of vegetable and animal oils used as antifoam agents and the metabolization of fatty acids released were analysed during fermentation of T. vulgaris in a 30 l jar fermenter. During cultivation time of 22 hours the oil amount decreased by 60 to 70%. The metabolization of fatty acids is 50 to 90% of the starting level depending on the kind of acid. The eventual effect of the fatty acids released from antifoam oils on the protease production is discussed.
Analytik Atypischer Fettsäuren in biologischen Matrizes
Authors: Pöurschmann J. , Pörschmann S. , Liebetrau L. , Richter K. 
Published: December 2004

AbstractBy combined application of chemical pretreatments, capillary gas‐chromatography and mass spectrometry it was possible to enlighten the structure of atypical fatty acids with hydroxy groups and cyclopropane rings under the use of only a few of reference substances.The direct alkaline saponification of the sample with liberation of fatty acids and following methylation with boron trifluoride/methanol or diazomethane was proved to be the best method regarding to precision and speed of the sample cleanup.
Production of a white wine and a protein‐rich soy flour by yeast fermentation of soybean slurry, soybean milk and the whey from tofu production
Authors: Yee V. , Wellington G. H. , Olek A. , Steinkraus K. H. 
Published: December 2004

AbstractA dry white wine with an alcoholic content of 10 to 14% v/v was produced by yeast fermentation of slurried ground soybeans, soybean milk and whey from tofu production. Wines from whey and soybean milk were judged by a 20 member taste panel to be acceptable and comparable to a commercial chablis control. Chemical analysis indicated that the high fat and protein contents of soybeans do not cause a problem in the production of wines from soybeans as the lipids and proteins are precipitated by the acid and alcohol formed during the fermentation. The less recovered following fermentation were dehydrated and ground to a flour having an enriched protein content due to the yeasts and an improved flavor resulting from the yeast fermentation.
Microbiological solubilization of metals from complex sulfide ore material in aerated column reactors
Authors: Puhakka J. , Tuovinen O. H. 
Published: December 2004

AbstractFinely ground ore material (90%–200 mesh) was subjected to acid microbiological leaching in 20% and 30% (wt/vol) suspensions. The rate of aeration was maintained at 2 and 4 1/min · 1. After the onset of the microbiological phase of leaching, the solubilization of iron was initially rapid but was succeeded by Fe(III) precipitation. Major differences were apparent between inoculated and uninoculated suspensions for each metal analyzed (Fe, Al, Co, Cu, Ni, Zn). The sulfur balance in leach residues indicated elevated levels of elemental S and sulfate in the inoculated systems.
Sorption von Cellulase an Weizenstroh und seine Komponenten
Authors: Schulz G. , Hirte W. , Jacoplan V. , Philipp B. 
Published: December 2004

AbstractBy comparing different activity data of the buffered cellulase solution before and after contact with the substrate the interaction between Penicillium janthinellum cellulase and wheat straw, resp. its components (holocellulose and isolated lignin) has been investigated. The loss of activity due to sorption or denaturation has been found to differ widely between the different activity data and between the various substrates. A remarkable loss of enzyme activity was observed after contact with isolated straw lignin. The differences in activity decrease between the cellulose and the lignin moiety were found to be largent with the cellobiase activity.
Immobilized glucose dehydrogenase for cofactor regeneration in heme‐catalyzed demethylation and hydroxylation reactions
Authors: Kirstein D. , Kühn; M. , Schubert F. , Pohr P. , Scheller F. 
Published: December 2004

AbstractGlucose dehydrogenase (E.C. 1.1.1.47) from B. megaterium M 1286 was immobilized together with mutarotase (E.C. 5.1.3.3) on several organic carriers and by different methods. The storage stability of the enzyme at pH‐values > 6 is slightly improved by immobilization and the pH‐optimum is shifted from 8.3 to 8.0. Kinetic constants of the immobilized enzyme are: K′M(NAD+) = 5.36 × 10−4 mol/l K′M(glucose) = 3.76 · 10−2 mol/l and V′max = 5.54 · 10−5 mol/(l min g carrier) for the most active preparation (2.16 mg enzyme/g carrier).In reactor experiments the immobilized glucose dehydrogenase was used with glucose to regenerate NADPH in NADPH‐dependent iron‐III‐protoporphyrin‐IX‐imidazole catalyzed hydroxylation and demethylation of model substrates of cytochrome P‐450.The advantages of the coupling of both reactions with cofactor recycling are shown and discussed.
Degradation of lignocellulosic residues by polyporus versicolor and the effect of moisture contents and phenolic compounds
Authors: Arora D. S. , Sandhu D. K. 
Published: December 2004

AbstractPolyporus versicolor was selected to find out its ability to degrade four different lignocellulosic residues (angiospermic wood sawdust, sugarcane bagasse, paddy and wheat straw) under semisolid conditions. The production of laccase was also studied on these substrates. Sawdust suffered a maximum lignin loss though overall reduction in weight was maximum in paddy straw. Addition of malt extract and certain phenolic compounds (gallic acid, tannic acid and orcinol) favoured ligninolysis in sawdust. A moisture level of 5 ml/g of sawdust was found to be the most suitable for degradation whereas laccase yield increased with further rise in moisture content.
Rolle der einzelnen Komponenten des Cellulasekomplexes bei der Hydrolyse unlöslicher Cellulose
Authors: Klyosov A. A. , Kude J. , Goldstein G. Ch. , Meyer D. 
Published: December 2004

AbstractThe kinetics of the hydrolysis of microcrystalline cellulose (MC) by a Trichoderma reesei cellulase complex and by the individual endoglucanase (pI 4.4–5.2) and cellobiohydrolase (pI 4.0–4.2) has been studied. A flow chart for the enzymatic hydrolysis of the cellulose has been revealed, which formed a basis for a computer simulation of the kinetic regularities observed. As a result of it, the values of the catalytic rate constants for the individual stages of the enzymatic degradation of MC have been calculated. Then, the synergistic behaviour of endoglucanase and cellobiohydrolase in the hydrolysis of MC has been described both quantitatively and graphically. The relative efficiency of the individual stages for the MC hydrolysis in terms of glucose and cellobiose formation for cellulase complexes of various composition has been calculated. It was quantitatively shown that cellobiohydrolase plays the key role in the MC hydrolysis by T. reesei cellulase preparations, because it gives up to 80% glucose and up to 80–90% cellobiose in the presnce of endoglucanase which in turn plays a relatively minor role in a direct formation of both soluble products of the hydrolysis.
Verfahren und Analysenautomat zur Bestimmung von Nährlösungskomponenten und Stoffwechselprodukten
Authors: Weise H. , Kreibich G. , Scheller F. 
Published: December 2004

AbstractA continuous flow system with an enzyme electrode and with a new type of measuring instrument, the BIOXY‐Meter, is described as an example for the determination of glucose. The BIOXY‐Meter combined with various biosensors may be used in biotechnology and in other fields for the solution of a number of analytical problems. Measuring principle is the reduction of oxygen. The peak of first derivation of the current‐time‐curve is proportional to oxygen consumption and to decrease of substrate concentration. Enzyme fixation with common adhesive and a device for automated saturation of measuring samples with air in the sampler are also described. With the apparatus 60 samples per hour are analyzed for glucose. The linear measuring range is 0.1 mMol to 1.5 mMol with a coefficient of variation of Vk = 0.93 per cent. The described type of enzyme electrode is stable for 2 to 12 weeks or 1,000 to 5,000 measurements.
Ethanol concentration determination using solvent extraction and refractometry
Authors: Lazarova G. , Genova L. , Kostov V. 
Published: December 2004

AbstractThe feasibility to avoid the distillation in the case of refractometric determination of the ethanol concentration in fermentation samples is examined. The results obtained show that the ethanol concentration in the range 0 to 100 g.1−1 can be easily determined by means of benzyl alcohol extraction and refractometry.
Effects of temperature on microbial ethanol production. II. A thermodynamic interpretation of the temperature profile curve of ethanol production
Authors: Richter K. 
Published: December 2004

AbstractAn attempt is made to give a thermodynamic interpretation of the complete temperature profile curve of ethanol formation. Taking into consideration an enhancing competition between thermal activation and thermal deactivation of ethanol formation at increasing temperatures and supposing that the ethanol production is affected by a reversible and an irreversible term of thermal deactivation of a modified ARRHENIUS equation being current for the total biokinetic sphere may be derived:

.The quantities ΔH and ΔHD2T are identical with the temperature functions of the change of entropy caused by reversible and irreversible deactivation of ethanol formation, respectively. Accordingly for the yeast strain Saccharomyces cerevisiae Sc 5 the calculated entropy coefficients of reversible and irreversible thermal deactivation of ethanol formation amount to C = (0.245± 0.013) kJ/mol · deg.2 and C = (1.657 ± 0.046) kJ/mol · deg.2.
Submerged fermentation of cellolignin materials (compared with solid‐state fermentation and other alternatives)
Authors: Zeltina M. O. , Leite M. P. , Vanags J. J. , Apine A. J. , Viesturs U. E. 
Published: December 2004

AbstractThe review characterizes the submerged and solid state fermentation processes (SF and SSF) for obtaining of microbial biomass protein (MBP) on cellulose‐ and lignin‐containing (CL) agricultural wastes (straw, wine, branches of fruit trees). There are discussed other alternatives as well. The main technological parametres are presented (protein (biomass) yield, degree of available substrate utilization, process efficiency, etc.). The use of a special stirring system of the authors' design for mycelial cultures results in an increase of CL substrate concentration in the initial nutrient medium from 2% to 8%of dry matter (DM) and in a threefold increase of the specific productivity (from 0.07 g biomass/l · h to 0.21 g biomass/l · h). The technological parametres can be increased also in the processes with substrate addition. The obtained preparations are analyzed as to their usefulness for the feeds of ruminants.
D‐amino acid oxidase, aromatic L‐amino aminotransferase, and aromatic lactate dehydrogenase from several yeast species: Comparison of enzyme activities and enzyme specificities
Authors: Bode R. , Birnbaum D. 
Published: December 2004

AbstractProduction of D‐amino acid oxidase, L‐aromatic aminotransferase and aromatic lactate dehydrogenase by several yeast species was examined. Of 16 strains tested, Trigonopsis variabilis and Rhodosporidium toruloides were found to be most suitable for D‐amino acid oxidase production, T. variabilis and Brettanomyces anomalus for L‐aromatic aminotransferase production, and Hansenula polymorpha, Cryptococcus terreus, and Candida maltosa for aromatic lactate dehydrogenase production. This selection is based on a high amount of enzyme activity as well as a broad enzyme specificity. The data will be reported here.
A Procedure for gluconic acid synthesis with bacteria made continuous by means of an auxiliary substrate
Authors: Babel W. , Müller R. H. 
Published: December 2004

AbstractA method is introduced which makes a continuous oxidation of glucose to glucose acid possible. This method is based on the auxiliary‐substrate concept and co‐metabolism, respectively. Micro‐organisms (e.g. Acinetobacter calcoaceticus), which cannot assimilate glucose, but merely oxidize it, are grown continuously on a heterotrophic substrate (e.g. acetate). While growing they simultaneously synthesize gluconic acid. The productivity of the gluconic acid synthesis with a given strain depends on the dilution rate and the mixing proportion.Since growth and product synthesis are closely connected and growth yield is very much higher due to an auxiliary substrate effect in the presence of glucose than on the heterotrophic substrate alone, this method is suitable for SCP production as well. The productivity of gluconic acid production is controlled at a certain dilution rate by the mixing proportion of the growth substrate and glucose.