bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methanol‐Assimilation durch ein acidophiles Bacterium der Gattung Acetobacter
Authors: Babel W. 
Published: December 2004

AbstractGenerally, methylotrophic bacteria grow optimally in a pH range between 6 and 7.2. The assimilation of methanol can take place via several pathways. Acetobacter methanolicus preiers an acidic pH range for growth, the pH optimum is about 4, and it uses the FBP variant for methanol assimilation.The latter is interesting from a regulatory point of view because phosphofructokinase disappears during growth on glucose, which is assimilated via the hexosemonophosphate pathway. Since Entner‐Doudoroff enzymes and phosphoketolase are absent in A. `ethanolicus as well as in non‐methylotrophic Acetobacter and Gluconobacter species phosphofructokinase becomes a key enzyme of the assimilation of methanol.Although A. methanolicus uses the hexulosephosphate pathway the growth yield on methanol is smaller than with other “hexulosephosphate pathway bacteria” e. g. with obligate methanol assimilating bacteria.At first sight it may appear that the acidic optimum pH is responsible for the smaller growth yield and the discrepancy between the experimental and predicted values.The relationship between the dependence on and the protection from, high external proton concentration on the one hand and the causes of the low growth yield on the other are discussed. Accordingly, A. methanolicus and another heterotrophic acidophiles seem to be acidoresistant above all, their machinery guaranteeing the protection from the high proton concentration is responsible for the acidophily and the low growth efficiency is caused by a simple respiratory chain.
Untersuchungen zur Anreicherung von Ergosterol und Ubichinonen aus Lipid‐Kohlenwasserstoff‐Fraktionen
Authors: Vier B. , Voigt B. 
Published: December 2004

AbstractAdsorption on Silicagel was used for the enrichment of ergosterol and ubiquinone‐9 from a lipid‐hydrocarbon extract. The main components of the lipid‐hydrocarbon extract were hydrocarbons of gas oil (B. p. 513 to 653 K)phosphatides, glycerides, and fatty acids.By adsorption on silicagel (1 part silicagel to 2–3 parts of lipid‐hydrocarbon extract dissolved in hexane) were ergosterol and ubiquinone‐9 enriched and nearly completely separarated from hydrocarbons and phosphatides, partly from glycerides and fatty acids. Ergosterol and ubiquinone‐9 can be obtained by a simplified separation from the enriched fraction.
Rechnergestützte Führung von Fermentationsprozessen, Teil 4
Authors: Prause M. , Schulz H.‐J. , Wagler D. 
Published: December 2004

AbstractIn parts 1–3 of the publication exceptionally stationary processes were used as information sources. In this fourth part the application of transition states for the adaption of the static model is investigated. A solution on the basis of a simple disturbance model is proposed and an evaluation of this procedure is given.
Zu Problemen der Photosynthesemessungen bei der Kultivierung von Mikroalgen
Authors: Arndt H. , Tschirner E. , Böhm H. 
Published: December 2004

AbstractThe rate of photosynthetic activity of a single alga cell, their variability in the course of individual life, the time dependence of conditional influences, the dependence of the action of the condition on the registered parameter are shown by results of our measurements. The further underline the necessity of parallel short‐ or longtime measurements with several charges. Under these conditions, techniques on the basis of gasanalysers are profitable for the planning of measuring systems for photosynthesis with the ability to continuous, simulataneous in vivo measurements of photosynthetic rates of O2‐output and CO2‐fixation in open gas‐stream with parallel charges. A measuring system, which meets these requirements, is demonstrated.
Der Einfluß der Konzentration von Ethanol und Essigsäure auf den Adenylat‐Pool bei Acetobacter Rancens
Authors: Hitschmann A. , Zucker‐Kerbler D. 
Published: December 2004

AbstractThe influence of ethanol and acetic acid concentration on the ATP‐pool and energy charge of Acetobacter rancens was investigated.The behaviour of growth and ATP‐pool is contrary one to each other. An increasing concentration of acetic acid results in decreased growth rate, ATP‐pool and energy charge.
Bestimmung des isoelektrisch fällbaren Proteins aufgeschlossener Mikroorganismen mittels Coomassiebrillantblau G‐250
Authors: Pauli G. , Kreuter Th. 
Published: December 2004

AbstractAn analytical method for a rapid determination of the protein dissolved from microorganisms after cell disintegration and protein extraction is presented, thereby distinguishing both the isoelectrical precipitable and the isoelectrical nonprecipitable protein fraction. The method is especially usefull for controlling disintegration and protein extraction steps in production of protein isolates from microbial biomasses.
Der Laborkleinfermentor LF2 – Physikalische Kenndaten, Beurteilung der Originalkonfiguration und Charakterisierung spezieller Ausrüstungsvarianten
Authors: Grosse H. H. , Reichenbach P. , Bocker H. 
Published: December 2004

AbstractThe stirred laboratory scale fermenter LF2 is a powerful device for fermentations with up to 3 liters culture broth [1]. It was designed in the Academy of Sciences of the C.S.S.R. and has found a rather wide application in a great number of organizations working in the fields of biotechnological education, research and industry in the G.D.R. and the C.S.S.R.The LF2‐fermenter is well suitable for carrying out a broad manifold of aerated biotechnological works without contaminations in basic research and process development.The mechanic and electronic design gives a lot of room for the realization of special equipment variants like special‐shaped reactor vessels or special electronic moduls for automatic control.
Autohydrolysis extraction process as a pretreatment of lignocelluloses for their enzymatic hydrolysis
Authors: Targoǹsky Z. 
Published: December 2004

AbstractAutohydrolysis was studied as a pretreatment to enhance sugar yields from enzymatic hydrolysis of wheat and rape straw, beech, birch and poplar sawdust. Reaction temperatures were 185°C to 212°C and the reaction time 20 min. The pretreated slurries were hydrolyzed with “Novo” cellulase and Fusarium sp. 27 cellulase at 45°C and pH 4.8 for 24 h with addition of Fusarium sp. 27 cellbound cellobiase. From 85% to 90% sugar content of substrates were converted to reducing sugars after 24 h enzymatic hydrolysis, with exception of poplar wood.10.8 g biomass was obtained after cultivation of Fusarium sp. 27 with water solution hemicellulose fraction from 100 g beech sawdust autohydrolyzed at 200°C during 20 min.
Modelling oscillatory behavior in batch fermentations
Authors: Lenbury Y. , Steppan J. J. , Park D.‐H. , Tanner R. D. 
Published: December 2004

AbstractA batch fermentation is modelled with constant and variable yeild terms. It is shown that the model cannot exhibit oscillations if a constant yield term is used. Oscillations in the cell concentration, but not in the limiting substrate concentration, can be simulated if a variable yield function of the limiting substrate is used. Conditions, for which the variable yield needs to satisfy in order to generate oscillations in the cell concentration, are discussed. The primary condition is that the yield must become zero at the same time that the specific growth rate does. Experimental results exhibiting oscillatory behavior are presented and compared with the proposed model.
Exogenous cellulases of thermophilic micromycetes. Part I. Selection of producers
Authors: G. Kvesitadze , L. Kvachadze , T. Aleksidze , D.K. Chartishvili 
Published: December 2004

AbstractMore than 600 micromycetes – representatives of different genera have been investigated for their ability to produce exogenous cellulases. Most of the investigated cultures were found to produce these enzymes, 24 cultures being thermophilic, and 18 thermotolerant. Cellulase or its derivatives proved to be the most favourable carbon source for cellulase secretion. None of the thermophilic cultures studied manifested the ability of exogenous exoglucanase biosynthesis. Using UV‐rays as mutagen, a mutant strain A. terreus T‐49 has been obtained being characterized by an increased endo‐glucanase and cellobiase activity, as compared to the initial strains. The cellulase preparations of thermophilic micromycetes contain one cellulasic component: endo‐glucanase, or two: endo‐glucanase and cellobiase.
Biotransformations. XIX. Reduction of some terpenic ketones by means of immobilized cells of rhodotorula mucilaginosa
Authors: Mironowicz A. , Siewinski A. 
Published: December 2004

AbstractReduction of (−)‐menthone ((−)‐1), (+)‐(R)‐methyl‐α‐campholenone ((+)‐2), (+)‐carvone ((+)‐3), and eucarvone (4) was carried out by means of cells of the Rhodotorula mucilaginosa species immobilized in polyacrylamide gel. Alcohols with the (S)‐configuration, (+)‐neomenthol ((+)‐1a), (+)‐(R)‐methyl‐α‐campholenol ((+)‐2a), (−)‐neoisodihydrocarveol ((−)‐3a), dihydroeucarveol ((−)‐4a), and small amounts of (−)‐dihydroeucarvone ((−)‐5), were obtained. The cells of R. mucilaginosa maintained after this reaction ability to reduce standard acetophenone to (−)‐1‐phenyl‐1‐ethanol.
Xylan‐Containing supports used to separate xylanase from the cellulases of aspergillus terreus F‐413
Authors: Paszczyński A. , Rogalski J. , Szczodrak J. , Dawidowicz A. 
Published: December 2004

AbstractThe separation of xylanase from cellulolytic enzymes of A. terreus F‐413 by affinity chromatography on xylan‐containing supports was investigated. Xylanase purified over tenfold was obtained after column chromatography on xylan bound to controlled porous glass. The molecular weight of the purified enzyme has been found to be 140 000 daltons, and it is homogeneous in polyacrylamide gel electrophoresis. Purified xylanase also showed residual celluloytic activity (perhaps cross‐specificity) with cellulosic substrates.
Herstellung von L‐Lysindecarboxylase aus Klebsiella pneumoniae
Authors: Huber J. , Weisbach F. 
Published: December 2004

AbstractL‐Lysine decarboxylase (LL‐Lysine carboxylase E.C. 4.1.1.18) is produced by a strain of the genus Klebsiella.The bacterial cells are cultivated at a temperature of 37°C with and without shaking. The production of LL‐Lysine decarboxylase is increased by adding of LL‐Lysine to the medium. At the end of cultivation the cells are killed by thymol, washed in water and dried by means of acetone and ether.Compared with specimen derived from other bacteria the LL‐Lysine decarboxylase in the shape of dried cells shows a high specific activity. The preparations are free of disturbing enzyme activities, have a high level of stability and may be used for determining of LL‐Lysine by means of enzyme electrodes.
Assimilation of animal fats by yeasts and synthesis of protein by continuous cultivation in a complex nutrient medium
Authors: Kostov V. , Popov B. , Popova L. , Kehlibarova L. , Borisova I. 
Published: December 2004

AbstractUnder the conditions of continuous cultivation studies were carried out on a mixed culture (association) with two strains of yeasts: Candida sp., assimilating animal fats, and Candida scottii, assimilating reducing sugars. A complex nutrient medium of wood hydrolysate was used.It was established that in this medium, at a rate of dilution of D = 0.25 h−1, the mixed culture assimilates the fats and the sugars simultaneously. As a result of this the yield of absolutely dry yeasts with regard to the total sum of fats and sugars amounts to 71% in the case of incineration fat and to 82% in the case of technical pork fat.The contents of protein, amino acids, lipids and ashy substances in the yeasts obtained from a medium with fats do not differ substantially from those obtained from the same medium without fats.
Hybridoma cells produced by electrofusion in a homogeneous electric field
Authors: Abel H. , Stolley P. , Dreyer G. , Walther I. , Junge C. 
Published: December 2004

AbstractIn the customary technique will be used a fusion chamber with an inhomogeneous electric field. The disadvantage is that the fusion conditions are not constant in the chamber. Yet for di‐electrophoretic collection of the cells their own field‐inhomogenizing influence is sufficient that is, the electrofusion can proceed also in very simple chambers with homogeneous fields.
Increase and limits of growth yields for heterotrophic microorganisms
Authors: Babel W. 
Published: December 2004

AbstractSubstrates for heterotrophic growth of microorganisms are more or less energy‐limited.In order to improve the growth yields phenotypic and genetic measures come into consideration. By means of the auxiliary substrate concept the carbon metabolism determined carbon conversion efficiency of about 75% for C2 compounds (i.e. non‐glycolytic, gluconeogenetic substrates) and about 85%, respectively, for C3 or glycolytic substrates can be attained experimentally.With methylotrophic microorganisms the growth yield might approach to this limit if the methanol oxidizing methanol dehydrogenase (bacteria) and methanol oxidase (yeasts) are replaced by an NAD+‐linked dehydrogenase.Due to an increase in the overall P/O quotient up to the maximum this limit cannot be reached.
Saccharification of cassava peels waste for microbial protein enrichment
Authors: Odunfa S. A. , Shasore S. B. 
Published: December 2004

AbstractCassava waste peels may constitute up to 55% of the original tuber. These waste peels were found to contain 41.8% carbohydrate, 1.1% protein, 12.5% ether extract and 4.9%, 4.9% total ash. and 20.8% crude fibre. Studies were conducted to formulate a fermentation medium to convert the waste peels to reducing sugars and to enrich the peels with microbial protein. Amylase producing microorganisms were isolated from rotten cassava tuber discs buried in the soil at different locations. The microorganisms isolated were Aspergillus fumigatus, A. flavus, A. niger, and a Pseudomonas sp. and A. niger; the level of reducing sugar was 20.5 mg/ml. The lowest was by B. subtilis an isolate from fermenting locust bean. Generally the levels of saccharification were higher when the waste media were supplemented with different nitrogen sourses. The crude protein yield in the cassava peel waste media by different microorganisms varied from 5.6% to 17.5%. The highest protein yield was in the waste medium fermented by A. fumigatus followed by A. niger, B. subtilis, Pseudomonas sp. in decreasing order.
Production of single‐cell protein with cellulomonas sp. on hempstalk wastes
Authors: Jeder H. , Deschamps A. M. , Lebeault J. M. 
Published: December 2004

AbstractStrains of Cellulomonas isolated from enrichment cultures with cellulose powder were cultivated with hempstalk wastes as the sole carbon source in a mineral medium. The yields of protein were not significantly different using the crude or alkali pretreated substrate in flasks experiments. Up to 12.5% protein was obtained on the untreated substrate with the best strain cultivated in a small fermenter.
Zur Wechselwirkung zwischen einer Penicillium‐Cellulase und wasserlöslichen Cellulosederivaten
Authors: Kasulke U. , Philipp B. , Polter E. 
Published: December 2004

AbstractEmploying anionic and non‐ionic cellulose ethers, differing in type of substituent and degree of substitution, as substrates, the pH‐profile of enzyme activity and the parameter Km and Vmax of the MICHAELIS‐MENTEN kinetics have been determined with Penicillium citrioviride cellulase in an homogeneous system. Within rather wide limits, a linear correlation was found between the DS of the substrate and Km or Vmax, respectively. Also the pH‐profile was found to depend on DS mainly, being bimodal at higher DS. On the other hand, no significant difference was observed between anionic and non‐ionic cellulose ethers of about the same DS with regard to the parameters determined. It is assumed, that substrate‐enzyme interaction is governed mainly by the length of non‐derivatized chain sequences mainly and not by Coulomb interactions.
Particularities in the kinetics of growth and citric‐acid accumulation by saccharomycoposis lipolytica
Authors: Behrens U. , Thierrsch A. , Weissbrodt E. , Stottmeister U. 
Published: December 2004

AbstractWhen glucose is used as C‐source extracelluar citric‐acid accumulation does not start at the point of N‐source exhaustion. A transition phase lasting for about 2–3 hours is observed. It may be assumed that the continuation of growth after the N‐source exhaustion coincides with the delay of the citric‐acid accumulation. During the course of citric‐acid production characteristic interruptions of the glucose uptake and the citric‐acid accumulation are found. The findings are discussed in more detail.
Formation of higher alcohols and phenol by strains of zymomonas sp.
Authors: Rao S. C. , Jones L. P. 
Published: December 2004

AbstractStrains of the bacteria Zymomonas sp. were studied for their ability to form higher alcohols. In a complex growth medium, six strains were shown to produce significant amounts of 1‐propanol, 1‐butanol, 2‐methyl‐1‐butanol, 3‐methyl‐1‐butanol, 2‐methyl‐2‐butanol, pentanols, secondary hexyl‐alcohols, and trace amounts of n‐hexanol. When resting cells of these organisms were placed into a fermentation medium containing glucose and Tris‐buffer, Z. mobilis 8938 produced increased levels of 1‐butanol, and secondary hexyl‐alcohols at concentrations of 13.5 mg/liter and 5.8 mg/liter, respectively. Another strain, Z. mobilis subsp. mobilis B 806, stimulated the formation of 1‐propanol and 1‐butanol at concentrations of 14.9 mg/liter and 23.52 mg/liter, respectively. Amino acids or amino acid precursors were then added to the fermentation medium. The presence of threonine and α‐ketobutyric acid stimulated Z. mobilis 8938 to produce 82.6 mg/liter secondary hexyl‐alcohols and 8.0 mg/liter n‐hexanol, respectively. Isoleucine and valine increased the production of 2‐methyl‐1‐butanol (394.0 mg/liter) and 3‐methyl‐1‐butanol (113.4 mg/liter), respectively, by Z. mobilis subsp. mobilis B 806. Glutamine enhanced the formation of 2‐methyl‐2‐butanol production to concentrations 38.8 mg/liter in Zymomonas strain B 806. Additional experiments suggested that higher alcohol production could also be accomplished in the absence of glucose when cells were allowed to metabolize the precursors only. The effect of aromatic amino acids on phenol production was determined using resting cells of Zymomonas sp. The maximum yield of phenol (111.6 mg/liter) was found by Zymomonas strain 8938 in the presence of tyrosine. The addition of phenylalanine also stimulated this strain to form 71.4 mg/liter of phenol.
Einsatz eines Hybridrechnersystems zur Prozeßführung von Antibiotikafermentationen in einer Scale‐up‐Linie
Authors: Reimann B. 
Published: December 2004

AbstractA hybrid computer completes a scale up line to a computer coupled fermentation (CCF) system for data processing, monitoring and operator servicing, documentation and process control. Presented experiences using this arrangement were adapted and transferred to microcomputer systems.
Continuous ethanol production by zymomonas mobilis on an industrial scale
Authors: Sahm H. , Bringer‐Meyer St. 
Published: December 2004

AbstractThe specific growth rate of the ethanol producing bacterium Zymomonas mobilis was lower in the presence of oxygen than under anaerobic conditions. Aerobically, considerable amounts of acetaldehyde and acetic acid were formed in addition to the normal fermentation products, ethanol and carbon dioxide. This bacterium contains considerable amounts of pentacyclic triterpenoids, mainly 1, 2, 3, 4‐tetrahydroxypentane‐29‐hopane. It seems that stability and permeability of the cytoplasmic membrane of this rather ethanol tolerant organism is achieved by the hopanoid content. A continuous culture of Zymomonas mobilis produced 60 g/l ethanol over a test period of 39 days. This strain was used for ethanol production from an enzymatically hydrolyzed wheat starch fraction on an industrial scale of 100 m3.
Regulation of sterol synthesis by glucose in baker's yeast
Authors: Novotný Č. , Běhalová B. , Doležalová L. , Zajíček J. 
Published: December 2004

AbstractThe ability of ten baker's yeast strains to synthesize sterols was checked. Ergosterol/24(28)‐dehydroergosterol (E/D) ratio had the value of 0.8 to 1 in most strains grown in a medium containing molasses as the carbon source. The ratio values were significantly increased in the cultures grown in a glucose medium. Both a decrease in the content of 24(28)‐dehydroergosterol and a slight increase of the ergosterol content were found to be responsible for the high values of E/D in the glucose‐grown cells. The strains examined could be divided into three groups on the basis of their behaviour towards glucose. The effect of the type of cultivation on sterol accumulation is demonstrated by comparing the sterol content of the representatives of the three groups of baker's yeasts grown in a fermenter or in shaken flasks.
Automatisiertes Laborfermentorsystem mit Mikrorechner „Elektronica‐60”︁ gekoppelt
Authors: Levitan J. S. , Viesturs U. E. , Kristapson M. Z. , Dunce M. E. , Arakeljan V. V. , Sarkissjanz L. S. 
Published: December 2004

AbstractThe microprocessor complex “Biotron‐M” designed for automation of experiments in microorganisms cultivation carried out simultaneously on no more than 3 fermenters is described. The complex is based on KTS LIUS‐2 and microcomputer “Elektronika‐60”.Information and control functions as well as the complete system are considered. The operating system “Rafos” with double‐task monitor is used as the system software. Special software is represented by a set of program modules performing the functions of the complex.An example is given concerning the operation of “Biotron‐M” together with fermentation plant “FU‐8”.
Einfluß des furfurals bei der Sulfitablaugeverhefung
Authors: Fischer K , Mohrmann K.‐H. 
Published: December 2004

AbstractIn the fodder yeast production from sulfite spent liquor (SSL) the content of yeast‐poisons in the SSL is of particular importance. The negative influence of sulfur dioxide has been known for a long time.Furfural is also named as a pollutant. Our own works showed that there is only an influence on the RS‐analysis and in this way a decrease of yield is simulated but not genuine.Practical results and theoretical calculations showed that 1.0 gram of furfural is equivalent to 1.88 g RS.This knowledge is of importance for carrying out the production process by simultaneous change of the furfural concentration. In this way the charge of the fermenter with carbohydrate can be too high or too low.
Enhanced Formation of β‐Glucosidase by Aspergillus niger VKMF‐2092 in Fed‐Batch Operation with Frequently Intermittent Glucose Addition
Authors: Kerns G. , Okunev O. N. , Ananin V. M. , Golovlev E. L. 
Published: December 2004

AbstractThe wild strain Aspergillus niger VKMF‐2092 forms β‐glucosidase on the basis of glucose as the sole carbon source. The formation of β‐glucosidase is initiated after the glucose concentration in the medium has reached a low level since the formation is subjected to catabolite repression. The β‐glucosidase is mainly cell‐bound and only released after a longer period. Under non‐repressed conditions the total formation of β‐glucosidase is not associated with growth.By supplying glucose in a fed‐batch‐technique, maintaining a low actual glucose concentration in the medium, the formation of β‐glucosidase is enhanced in comparison to simple batch fermentation. Using a fed‐batch‐technique with a frequently intermittent addition of glucose it is possible to increase the formation of β‐glucosidase with regard to both productivity and the activity related to the mycelium and the fermentation broth as well. The increase of productivity is about two to four times greater than at constant feed rate of the same overall amount of glucose.The reason for this increase will be discussed below. A method is presented which permits to investigate the influence of the substrate concentration and other parameters on the enzyme formation in short periods of one and the same fermentation run.