bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immobilization of fungal peroxidase on alkylaminated organic and inorganic porous supports
Authors: Łobarzewski J. , Kolarz B. N. , Wojcik A. , Wojaczynska M. , Trochimczuk A. , Blaszczynska T. 
Published: December 2004

AbstractSeveral alkylaminated porous silica gels and acrylic type porous polymers have been used for covalent binding of fungal peroxidase from Trametes versicolor. The immobilization efficiency expressed in terms of the bound protein content, specific enzyme activity, and enzyme storage stability have been determined for both types of supports used. The results indicate a better immobilization ability of organic polymers in comparison with silica gels.
Use of the luciferin‐luciferase assay of ATP for measuring the bacterial growth: Application to Escherichia coli
Authors: Kahru A. , Vilu R. 
Published: December 2004

AbstractThe relative constancy of ATP content per unit of dry biomass in different microorganisms enables to use the specific, sensitive and quick luciferin‐luciferase method for ATP assay for indirect quantitation of microbial biomass by measuring the ATP content in biomass samples.The aim of this work was to investigate the feasibility of using the ATP concentration for the monitoring of the growth of Escherichia coli K 12 W 3350 in different cultivation conditions. Statistically significant high correlation coefficients (r > 0.9) between the ATP content (ATP/ml) and the other growth characteristics examined showed that the ATP content of the culture is as suitable characteristic as the optical density of the culture, total cell number per ml or total cell volume per ml for the monitoring of the growth of E.coliin batch culture in mineral medium with glucose at different growth temperatures (27–42 °C) as well as in fed‐batch culture.
A mathematical approach for the estimation of biomass production rate in solid state fermentation
Authors: Leon J. A. Rodriguez , Sastre L. , Echevarria J. , Delgado G. , Bechstedt W. 
Published: December 2004

AbstractThe oxygen uptake rate (OUR) was studied in a solid state fermentation process of dried citrus peel with the strain Aspergillus niger QH‐2 in order to obtain the growth estimation of the microorganism in the system.The relationship between OUR, the maintenance coefficient (m) and the yield for oxygen consumption YO2 allows the estimation of the biomass rate if we consider that both parameters are not constants in some periods of the process.It was estimated that in the first 24th the strain has an specific growth rate of 0.174 h−1 with values for YO2 and m in the order of 2.84 g‐cell/g‐oxygen and 0.006 g‐oxygen/g‐cell ·h respectively.
Experimentelle Untersuchung, Modellierung und optimale Berechnung eines mehrstufigen Säulenfermentors. III. Algorithmus zur computergestützten Berechnung einer optimalen Projektierung für einen mehrstufigen Säulenfermentor
Authors: Kafarov V. V. , Gordeev L. S. , Vinarov A. J. , Semenova E. A. 
Published: December 2004

AbstractIn this third part of the paper a total algorithm for the optimal technological calculation of all processes which occur in an aerobic tower biochemical reactor devided in sections is presented. The algorithm was worked out on the base of a mathematical model [1], experimental data and the calculation of the model parameters [2]. This part of paper also includes the mathematical description of the fermentation process and results of a computer‐aided analysis of the influence of design, hydrodynamic, mass transfer, kinetic factors and energy parameters on the local and global criteria of the optimization.
Fed‐batch cultivation of methanobacterium formicicum and its fluorometric monitoring
Authors: Kuschk P. , Kevbrin V. V. 
Published: December 2004

AbstractFed‐batch cultivation of Methanobacterium formicicum Z‐281 was performed under substrate limiting conditions. Specific rate of culture growth amounted to 0.041 h−1, cell yield related to substrate was 0.6 mg proteine/mM formate. Significant increase of coenzyme F420 content in cells depending on time of cultivation was observed. Increase of the fluorescence intensity of the medium was also observed with the accumulation of biomass. These parameters were suggested for tracking culture growth. The possibility of application of fluorescent factors for methanogenic population control in the anaerobic digester is discussed.
Improved brewing and preservation of pito, a nigerian alcoholic beverage from maize
Authors: Onaghise E. O. , Izuagbe Y. S. 
Published: December 2004

AbstractA controlled brew of pito was produced and compared with a native brew. The former contained a higher alcohol content than the latter brew and was brighter in colour (13 as against 18.5 EBC units) thus making it more attractive. Of various heat and chemical preservative treatments used to prolong the shelf life of both products, pasteurization at 75°C for 30 min. and treatment with sorbic acid at a concentration of 5% were best able to arrest microbial proliferation in the bottled products during a 4 week storage period.
Production of lysine by mutants of escherichia coli K 12 in a medium with lactose
Authors: Sobotková L. , Sikyta B. , Smékal F. 
Published: December 2004

AbstractIn an effort to use whey for lysine production, we isolated from a β‐galactosidase‐hyperproducing strain of E. coli K 12 multiple mutants – auxotrophic, regulatory and penicillin‐resistant. These mutants exhibited for the most part a high reversion rate but some of them produced about 2 mg/ml lysine in an enriched fermentation medium.
Möglichkeiten zur Steigerung der Schwermetallsorptionsleistung von Mikroorganismen
Authors: Iske U. , Hübner K. 
Published: December 2004

AbstractThe sorption capacity of silver on different biological materials has been investigated depending on physico‐chemical pretreatments. The maximum silver loading values measured were compared with the values obtained with nontreated biomasses.The results show an increase of the loading capacity up to a factor of 10 in case of the alkalitreated biomasses. When the biomasses are extracted before being used as adsorbent with a solvent mixture of chloroform/methanol in a ratio of 2:1 the efficiency of the silver adsorbing power can be increased.Beyond that, the ability to adsorb silver can also be influenced when microorganisms are used as biocatalysts in a product synthesis before they are used as adsorbents. A strain of Acetobacter methanolicus possesses 1.8 times higher affinity to silver when it is employed in a process of gluconic acid production before adsorption. Physico‐chemical pretreatments influence not only the loading capacity of the biological material, but also the contacting time required for the establishment of the adsorption equilibrium can be considerable reduced.
Simulation of a bacterial population structure in continuous cultivation by a dissociation process: An application to Rhodococcus rubropertinctus
Authors: Drozdov‐Tikhomirov L. N. , Grizhebovskaya A. T. , Mil'ko E. C. 
Published: December 2004

AbstractAn attempt is made to give a quantitative estimation of a possible contribution of the dissociation process in the formation of the heterogeneous population structure for the Rhodococcus rubropertinctus (Micobacterium lacticolum) in continuous cultivation. This estimation is realised with the help of a constructed mathematical model of the process. The model equations obtained describe particular biomass changes for R‐, S‐ and M‐dissociants and changes for substrate (glucose) concentration within the chemostate in continuous cultivation. Next, contributions to dissociant biomass changes were taken into account: (1) cell reproduction (each dissociant has its own specific growth rate depending on the substrate concentration), (2) cell outflow (in proportion to dissociant biomass) and (3) dissociation (dissociant genotype change during reproduction occurs for each dissociant with its own specific frequency).It is determined that if substrate growth constants are equal the rapidly growing dissociants (possessing maximal μmax) outs the rest of them, and the greater the speed of the flow the less the time to reach a steady‐state distribution of the dissociant biomasses. But, at the same time the slowly growing dissociant can become dominant in the population if it has a lower substrate growth constant.
Biologische Erfahrung mit einem blasenfreien Begasungssystem (CHEMCELL)
Authors: Thalmann E. 
Published: December 2004

AbstractThe increased interest in large scale production of biologically active molecules, as for example monoclonal antibodys, hormones, proteins and enzymes, has stimulated a rapid development of different methods to cultivate eukaryotic cells. Further progress in this field of modern biotechnology is expected not only from the selection of more productive cell lines and more efficient cultivation techniques, but also from the improvement in new bioreactor design and operation, which guarantees increased productivity per unit volume and reduces the downstream processing. Most important factors for a new reactor design in future will be the energy‐ and mass transfer, shear stress and scaleability. The provision of an adequate oxygen supply to large scale reactors is the most critical barrier to scale up. If oxygen is limited in a small degree, the result is inhibition of cell density and cellular efficiency in the production of the desired biomolecules. In addition, when methodologies are used which allow high cell densities and high metabolic active cells, the oxygen transfer becomes more important and, at the same time, more difficult. Since direct sparging of air into the cell‐containing medium causes problems such as shear forces and foaming, new, efficient methods in bubble free aeration must be utilized. A new aeration system is presented, which is suitable to bubble‐free aeration as well to separation of microcarrier‐anchered cells from the harvested medium when running in a continuous perfusion mode. The efficiency of the CHEMCELL System regarding aeration and cell retention is demonstrated by the growth kinetics of BHK 21‐cells in batch and perfusion mode.
Some aspects of the regulation of nitrogen metabolism in the yeast genus candida. Study of the kineties of ammonium transport to the cells of hydrocarbon oxidizing yeast of the genus candida with a change in nitrogen nutrition
Authors: Gradova N. B. , Guselnikova T. V. , Belova A. P. 
Published: December 2004

AbstractIn his study the kinetics of the ammonium transport to he hydrocarbon‐oxidizing yeast cells and the specific features of its regulation as one of the aspects of catabolite nitrogen repression were investigated. As the objects 3 mesophilic strains of C. maltosa, the thermotolerant strain C. rugosa as well as a collection of the thermotolerant strain C. blankii BKM‐Y‐462 type were selected.
Wirkung eines mikrobiellen Enzympräparates, mit zellwandlytischen Eigenschaften auf Saccharomyces cerevisiae
Authors: Menzel G. , Schöps K. , Klein G. , Häfner B. 
Published: December 2004

AbstractThe effect of an enzyme preparation of Streptomyces spec. KT3 was tested in view of its cell wall lytic activity on cells of Saccharomyces cerevisiae. According to electron micrographs under the influence of the enzyme preparation protoplasts but no spheroplasts were formed. The yield of protoplasts amounted dependent on the enzyme charge to 75–99 per cent, most of the protoplasts were released after 60 minutes. Cells of 12 strains of Saccharomyces cerevisiae were able to be protoplasted and stabilized immediately thereafter by mannitol (0.8 M) or KCl (0.6 M). The presence of stabilizers already in the enzyme‐containing medium inhibited, however, protoplasting considerably. The stabilized protoplasts could be stored for six days at 4°C without any noticeable changes.
Effect of ensiling on the nutritive value of low quality roughage rice hulls. I. Microbial studies
Authors: Shawky B. T. , El‐Sayed O. H. , Zaki D. A. , Mouafi F. 
Published: December 2004

AbstractRice hulls were ensiled in laboratory silos in two separate experiments with the same treatments. In the first, sealing was delayed for a period of days. In the second experiment, silos were sealed immediately after filling. In each experiment, four treatments were applied, namely control, molasses 2% added, urea 0.5% added, and molasses 2% + urea 0.5% added.Lactobacilli, streptococci, and coliforms appear to form the main bulk of the flora characteristic of fresh rice hulls, while the lactic acid bacteria dominate at the commencement of the silage ripening. The characteristics of 30 representative pure strains of both lactic acid and coliform bacteria isolated from rice hulls laboratory silage are described. On the basis of morphological, cultural, and biochemical characteristics, the isolated cultures were identified as ten strains of Lactobacillus ten strains of Streptococcus, five strains of Klebsiella, and five strains of Escherichia.
Production of cellulase in a rotating disc fermenter using immobilized Trichoderma reesei cells
Authors: Sachse H. , Kude J. , Kerns G. , Berger R. 
Published: December 2004

AbstractThe production of cellulase was investigated in repeated batch experiments using immobilized cells of two Trichoderma reesei mutants in a rotating disc fermenter under very low shear stress. The enzyme production with one of the mutants was maintained for three successive batch cycles (ca. 30 days), while with the other mutant the cellulase formation lasted only one batch cycle (14 days) because of a genetic instability.The enzymatic hydrolysis of microcrystalline cellulose by the cellulase complex formed in the rotating disc fermenter is distinctly higher than that of cellulase produced in a stirred tank reactor, in which the higher shear stress partially damages the enzyme molecules, mainly those of cellobiohydrolase. The higher specific activity of the cellulase produced in the disc fermenter correlates with its higher capacity of adsorption onto microcrystalline cellulose.
In‐Situ recovery of ethanol from fermentation broth by hydrophobic adsorbents
Authors: Einicke W. D. , Gläser B. , Schöoullner R. 
Published: December 2004

AbstractThe in‐situ recovery of ethanol from fermentation by different hydrophobic adsorbents has been studied. Liquid phase experiments have demonstrated that pentasil zeolites have a high selectivity for ethanol in the low concentration range. It is shown that the contact of the fermentation broth with the zeolite NaZSM‐5 avoids the product inhibition. On the other hand, the ethanol production rate dramatically changes in dependence on the glucose‐to‐adsorbent ratio.
Application of UASB‐reactors to industrial waste‐water treatment; performance data and results in granulation control
Authors: Morvai L. , Miháltz P. , Czakó L. , Holló J. 
Published: December 2004

AbstractSeveral types of high organic matter pollutants containing (COD‐range: 3–50 kg · m−3) industrial waste waters were treated in laboratory scale (1.2–23 dm3) sludge blanket (UASB) and UASB‐fixed bed hybrid (UBF) reactors. In most cases higher than 80% of COD‐removal efficiency has been attained. The CO2 content of the biogas developed was mainly influenced by the neutralization (base to acid) ratio related to feed pH.Cell immobilization by granule formation was considered as a change in microbial population: enrichment and aggregate formation of Methanotrix‐like filamentous microorganisms. Based on physiological and physical indexes of microbial selection and with regard to the different sensitivities of microorganisms to substrate inhibition, a new start‐up method was developed for rapid (40–45 days) granulation of raw digested sludge.
Regulatory aspects of carbohydrate metabolism in relation to citric acid accumulation by aspergillus niger
Authors: Steinböck F. A. , Held I. , Choojun S. , Harmsen H. , Röhr M. , Kubicek‐pranz E. M. , Kubicek C. P. 
Published: December 2004

AbstractFermentative production by the fungus Aspergillus niger is the world's exclusive source of citric acid to be used for the food, pharmaceutical and detergents' industry. The extraordinary high yields and the delicate nutrient requirements of this process have attracted numerous investigations on its mechanism. This review highlights recent results on the regulation of its biosynthesis, emphazising especially (a) the role of pH, (b) the role of type and concentration of the carbon source, and (c) the role of anaplerotic carbon dioxide fixation in the accumulation of citric acid.
Growth behaviour of filamentous fungi with varying N supply
Authors: Weichert D. 
Published: December 2004

AbstractInvestigations simulating solid‐state fermentation, SSF, were carried out to study the influence of a varying N supply on the growth of a mycelium.Experiments with two fungi and two N sources demonstrated the high adaptability of the mycelium to a deficit of nitrogen over a wide range of N supplies. The mycelium of the fungi Gliogladium sp. and Aspergillus sp. can grow up to the very low crude protein content of 11–15%. But protein‐poor biomass could not make up the deficit of protein even under optimal cultivation conditions, that means the state of the mycelium remains irreversible. This showed the limit of the adaptability of filamentous fungi, which has to be taken into account for mycelium growth in SSF.
Cross flow filtration of RNA extracts by hollow fiber membrane
Authors: Fernandez V. M. , Romano J. M. , Otero M. A. 
Published: December 2004

AbstractThe feasibility of using ultrafiltration to concentrate RNA was investigated. Ultrafiltration flux and solute retentivity were affected by membrane cut‐off and inlet pressure.The RNA can be concentrated by selecting a hydraulically permeable membrane (PM 30) and then operating the system at a sufficiently high pressure (2.07 · 105 Nm−2) and a high recirculation rate (150 cm−1). The use of this procedure was limited to a high‐flux regime. However, a very high retentivity of macrosolute was achieved. The effect of transmembrane pressure on the apparent mass transfer coefficient in the “gel polarization model” was discussed and related to ultrafiltration flux.
Application of genetic and genetic‐engineering methods to the production of food and food additives
Authors: Leuchtenberger A. 
Published: December 2004

AbstractThe last decade saw remarkable progress in the quantitative and qualitative improvement of microorganisms applied in the foodstuff industry because methods of genetic engineering were used. Compared to the classic methods of mutagenesis and hybridization, genetic engineering facilitates the changing of genes coding for certain products or certain qualities and their new combination with other genes in either the donor or any other host cell.Success achieved so far in the changing of microorganisms by mutagenesis, hybridization and genetic engineering is explained with some examples. These refer to microorganisms used in the production of enzymes, amino acids, edible organic acids, aromatic and similar products.
Biotechnology based opportunities for environmental protection in the uranium mining industry
Authors: Glombitza F. , Iske U. , Bullmann M. , Ondruschka J. 
Published: December 2004

AbstractFluorides and a sodium paraffin sulfonate were used as biocidial substances for blocking microbial oxidation reactions due to chemolithoautotrophic microorganisms and tested in a laboratory and pilot plan scale. A treatment of uranium containing effluents by means of a biosorption process for reducing the uranium concentration was demonstrated in a pilot plant scale too.
Rheological behaviour of some antibiotic biosynthesis liquids
Authors: Gavrilescu M. , Roman R. V. , Efimov V. 
Published: December 2004

AbstractThis paper prsents the results of teh study of rheological behaviour of antibiotic biosynthesis liquids obtained by submerged aerobic cultivation of microorganisms belonging to the actinomycete and fungi classes, in stirred tank bioreactors with turbine impellers. These liquids have a non‐Newtonian behaviour which follows the power‐law rhcological model with a correlation index of over 0.95.The studied liquids are pseudoplastic, and alter their rheological properties, such as consistency index, (K), flow index, (n), apparent viscosity, (ηa), maximum Newtonian viscosity (η0), with the culture age, microrganism strain and batch conditions. Also, these liquids are time dependent, exhibiting thixotropy.The most viscous liquids are produced by Streptomyces aureofaciens and Streptomyces rimosus cultivation, while that produced by Streptomyces griseus is the least viscous. A higher pseudoplasticity appears after 30 hours culture age.Since all these biosynthesis are aerobic, a careful observation of the rhelogical behaviour dynamics is necessary to avoid the oxygen culture supply limitation and the decrease of the bioreactor performance during biosynthesis.
Influence of sulphur dioxide on the fermentation of sulphite spent liquor
Authors: Mohrmann K.‐H. , Fischer K. 
Published: December 2004

AbstractIn fodder yeast production from sulphite spent liquor, sulphur dioxide is well‐known as a yeast poison. The present paper deals with the detailed influence of sulphur dioxide.The experimental work was done in a laboratory fermenter under technical conditions. A decrease in biomass yield, and an increase in oxygen consumption, caused by increasing carbon dioxide production, were found.During the fermentation, there is no destruction of the carbonyl‐bisulphite adduct to be observed. Sulphur dioxide has no influence on the crude protein content of yeast cells, and there is also no influence on the morphology of cells.
Age structured process modelling of a fermenter cascade with feed of fresh biomass
Authors: Kuse B. , Loettel W. 
Published: December 2004

AbstractThe aim of this paper is to show, how to model the effects of fresh biomass fed in order to avoid a damage of the microorganisms. The continuous ethanol production in a three stage cascade with fed fresh biomass and biomass recycling serves as an example of how information about the design of the start regime, the fresh biomass cultivation and the biomass removal are obtainable by a model containing viability balances.
A thermoacidophilic bacterium similar to Bacillus acidocaldarius
Authors: Zentgraf B. , Rogge G. , Nagel B. 
Published: December 2004

AbstractThe thermoacidophilic strain TAC1 was isolated from a sulphatara field. It grows heterotrophically on a synthetic medium, containing yeast extract and carbohydrates at 50 to 70°C and pH 2 to 5. The cells are motile spore‐forming rods utilizing, for instance, glucose, lactose, or sucrose as carbon substrate. They also used concentrated whey as nutrient medium.The maximum specific growth rate calculated from batch culture data of the strain TAC1 on glucose is 0.9 h−1 at 65°C and pH 3. The yield coefficient determined in a chemostat culture of the strain TAC1 on glucose, is 0.15 to 0.31 grams of cells produced per gram of glucose consumed (63 to 70°C, pH 2.2 to 4.0, dilution rate 0.2 to 0.4 h−1).The lipid fraction extracted from the cells consists of 72 to 93% of ω‐cyclohexyl C17 and C19 fatty acids. The composition of lipid fraction varied with the pH value and the dilution rate but not with the temperature.In regard to the morphology and physiology of the isolated strain as well as the high percentage of ω‐cyclohexyl fatty acids of the cell material, the strain TAC1 is similar to Bacillus acidocaldarius.
Fed‐batch production of concentrated fructose syrup and ethanol using Saccharomyces cerevisiae ATCC 36859
Authors: Koren D. W. , Duvnjak Z. 
Published: December 2004

AbstractA fed‐batch process is used for the production of concentrated pure fructose syrup and ethanol from various glucose/fructose mixtures by S. cerevisiae ATCC 36859. Applying this technique, glucose‐free fructose syrups with over 250 g/l of this sugar were obtained using High Fructose Corn Syrup and hydrolyzed Jerusalem artichoke juice. By encouraging ethanol evaporation from the reactor and condensing it, a separate ethanol product with a concentration of up to 350 g/l was also produced. The rates of glucose consumption and ethanol production were higher than in classical batch ethanol fermentation processes.