bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conversion of lactose to methane by defined bacterial cocultures
Authors: Schug A. , Schoberth S. M. , Sahm H. 
Published: December 2004

AbstractThe conversion of lactose — the main constituent of whey — to methane and carbon dioxide was studied using different defined constructed cultures, imploying strains of Methanosarcina barkeri, Methanobacterium bryantii, Escherichia coli, Acetobacterium woodii, Lactobacillus casei, and Lactobacillus plantarum. The following combinations of strains (food chains) were studied with respect to efficiency and yield of lactose conversion (methane yield in parentheses): E. coli and M. barkeri (4.5–7.6%), E. coli and M. bryantii (13.3%),E. coli, M. barkeri and M. bryantii (54%), L. casei, A. woodii and M. barkeri (93.3%). These conversions were carried out in pH controlled batch fermentations. A very efficient coculture was a combination of L. plantarum with A. woodii and M. barkeri: in chemostat cultures lactose was converted to methane and carbon dioxide with a yield of about 90%, at dilution rates of 0.27 d‐1to 0.37 d‐1.
Direction of the sustained oscillation trajectory in the cell‐product phase plane describing product inhibition on continuous fermentation systems
Authors: Lenbury Y. , Chiaranai Ch. 
Published: December 2004

AbstractA criterion for the direction (clockwise or counterclockwise) of the limit cycle in the cell massproduct phase plane is developed for a product inhibition model of a continuous microbial culture. It is then hypothesized that the model will not admit clockwise oscillations.
In situ – Phaseolotoxinproduktion durch permeabilisierte und immobilisierte Zellen von Pseudomonas syringae pv. phaseolicola
Authors: Schluttig A. , Teicher R. , Fritsche W. 
Published: December 2004

AbstractPseudomonas syringae pv. phaseolicola, the causal agent of halo blight disease of bean (Phaseolus vulgaris) produces Phaseolotoxin (Nδ‐(N′‐sulpho‐diaminophosphinyl)‐L‐ornithyl‐alanyl‐homoarginine) — a phytotoxic secondary metabolite — under laboratory conditions in a synthetic medium. Permeabilized (EDTA‐treatment) and immobilized (Agar Agar) cells of the bacterium are capable of producing Phaseolotoxin.Therefore an “in situ” production of this microbial phytoeffective compound using immobilized and permeabilized cells of Pseudomonas syringae pv. phaseolicola is possible.
Aspekte der Situationserkennung an Fermentationsprozessen
Authors: Pohl H.‐D. , Knorre W. A. 
Published: December 2004

AbstractThe establishment of an on‐ or off‐line‐optimal‐controlled fermentation process requires a system of situation identification — process rearrangement. The choice of the structure and the mathematical model of the situation is difficult. To characterize the situation it is necessary to determine the process‐specific vector which regards the major features of the processes. The determination of the structur and the vector which regards the major features of the fermentation process has been demonstrated by several examples.
Monitoring microbial product synthesis by measurement of the dehydrogenase activity
Authors: Gründig B. , Behrens U. , Kerns G. , Thiersch A. 
Published: December 2004

AbstractA method for the photometric measurement of dehydrogenase activities with the redox dye phenazine methosulphate at a fixed biomass concentration was applied for the investigation of idiophasic product synthesis. It was found that in citric acid fermentation by Yarrowia lipolytica which is characterized by a well defined separation into tropho‐and idiophase the magnitude of product synthesis rates corresponds to the level of dehydrogenase activity at the end of the trophophase. In cellulase production by Trichoderma reesei the tropho‐and idiophase are not well defined but a rise of dehydrogenase activity in the course of the idiophase is likely to correspond to an increase of the cellulase formating rate. The significance of the relation of dehydrogenase activity to production rates for monitoring industrial fermentations is discussed.
The pretreatment effect on wheat straw saccharification
Authors: Stoyanov I. , Ilieva S. , Savov V. , Panayotov H. , Dineva J. , Spasova D. 
Published: December 2004

AbstractEnzymatic hydrolysis of cellulose is potentially an attractive method for converting cellulose into glucose which can then be used as a chemical feed or as a growth substrate for a number of microorganisms to produce microbial products.An enzymatic hydrolysis of wheat straw with cellulase preparation “Trichocease” was made. The wheat straw used was pretreated mechanically and with NaOH. A procedure of pretreatment was investigated in 26 variants. The dynamics of enzymatic hydrolysis was studied. An assay of this dynamics based on the amount of reducing sugars formed during the cellulase reaction and depending upon enzyme and substrate concentration and time of action was carried out.
Some laboratory investigations of anaerobic waste‐water treatment process control in two different types of filter fermenters
Authors: Behrens U. , Schulze E. , Puschendorf K. 
Published: December 2004

AbstractAnaerobic degradation of a model waste water was investigated in two different types of fermenters (filter and hybride filter) under batch and continuous conditions. Gas production, COD removal, formation of fatty acids and the CoF420–content of the biomass were monitored. At both modes of action the filter showed more process stability.
Computersimulation der Trocknung biologischer Produkte
Authors: Mohr K.‐H. , Vondran J. 
Published: December 2004

AbstractThe extend of non‐enzymatic browning and ascorbic acid loss during air drying of a slab are predicted by computer, utilizing moisture and temperature dependencies of reaction kinetics together with simulated data for either averaged moisture contents. Results show that the extend of quality loss is a function of the drying parameters.The computer model is useful for the optimization of quality retention during dehydration of biotechnological products and foods.
Oszillierende‐fed‐batch‐Technik bei der Cellulasegewinnung
Authors: Kerns G. , Kude J. , Meyer D. 
Published: December 2004

AbstractFrom different fungal genera some mutant strains were selected which in cellulase formation exhibit reduced catabolite‐repression related to several soluble carbon sources. The cellulase production by these mutant strains on the basis of soluble carbon sources is possible if a fed‐batch‐technique is used for feeding the substrate.The optimum procedure is an oscillating‐fed‐batch‐technique (OFB) with feed‐back‐controlled intermittent addition of the substrate. The substrate concentration in the medium is adjusted in such a manner to realize oscillations between a limitation for mycelium growth and non‐limiting conditions under a substrate concentration which is yet below the repressing concentration for cellulase formation. A suitable feed‐back‐parameter for the control of substrate addition is the specific CO2‐formation of the mycelium.Using OFB the growth in cellulase activity is nearly proportional to the feeded substrate whereas the growth in mycelium is reduced. The productivity of cellulase formation is enhanced in comparison to continuous substrate addition as well as under limiting and non‐limiting conditions for growth of mycelium.
The production of ‘Orogo's’ — low alcoholic beverages from plantain (musa paradisica)
Authors: Akhimien A. , Uraih N. , Izuagbe Y. S. 
Published: December 2004

AbstractA laboratory version of orgoro; a low alcohol plantain beverage was found to possess a better odour, taste and colour after 7 days of fermentation compared with a native brew. The pH of the native brew decreased from 3.90 to 1.93 after 21 days of fermentation while the filterable acidity increased from 0.100 to 0.157%. The laboratory brew showed a decrease of pH from 4.60 to 2.72 and an increase in filterable acidity from 0.250 to 0.485%. Both brews had alcohol contents of 0.109 and 0.197% (v/v) respectively after this period. The total sugars content, soluble protein and total nitrogen contents of the native brew were 2.0 mg/ml, 1.3 mg/ml and 2.05 mg/ml respectively while values for the laboratory brew were 5.0 mg/ml, 2.2 mg/ml and 4.0 mg/ml respectively.
Kinetic study of pTG201 plasmid stability in Escherichia coli
Authors: Marin‐Iniesta F. 
Published: December 2004

AbstractRecombinant pTG201 plasmid coming from pBR322 plasmid, has been incorporated into Escherichia coli K12 to determine the influence of several culture conditions on the variation of the copy number. Continuous and batch cultures on LB medium without antibiotic selection and different oxygen tensions (21% and 100%) have been tested. The expression of pTGH201 encoded genes and the kinetics of plasmid loss differ significantly from the behaviour of pBR322 plasmid.
Characterization and preparation of chymosin from calf rennet samples by means of isoelectric focusing
Authors: Kleinert Th. , Lange I. , Rösicke B. , Honig A. , Schleusener R. 
Published: December 2004

AbstractChymosin has been identified in rennet samples from stomaches of living calfs by means of it's isoelectric points (IP), molecular weight (Mol. Wt.) and enzymatic activity.The values obtained by isoelectric focusing (IEF) and a two‐dimensional electrophoretic technique, amount 4,5…4,7 (IP) and 36 300 (Mol. Wt.) respectively. Furthermore the fractionation of calf rennet by IEF has been performed in a preparative scale. From one gramme of calf rennet we obtained 53 mg of purified chymosin, which shall be used for preparing antisera against chymosin.
Significance of the surface of immobilized Saccharomyces cerevisiae cells in ethanolic fermentation
Authors: Berger R. , Rühlemann I. 
Published: December 2004

AbstractS. cerevisiae cells immobilized in alginate beads show in many cases an increase of mean single cell volume during long‐time fermentations (successive batch cycles). The biomass loading capacity of the gel beads is characterized by a maximum volume but not by a maximum number of cells occupying the gel volume. In our system this loading capacity, i.e. the maximum volume fraction of cells per volume of beads, amounted to about 0.54. As a more important result it must be stated that the specific product formation rate in the case of fermentations negligibly influenced by diffusion hindrance is related to the total surface of the viable cells but not to their total number, total volume or total dry weight.
Biosynthesis of protein by microscopic fungi in solid state fermentation. I. Selection of Aspergillus strain for enrichment of starchy raw materials in protein
Authors: Czajkowska D. , Ilnicka‐Olejniczak O. 
Published: December 2004

AbstractA fungal strain suitable for protein enrichment of starchy raw materials was selected by evaluation of the growth rate, results of protein biosynthesis in solid state fermentation (SSF) and assessment of fungal biomass. The strain Aspergillus oryzae A.or. 11 selected for further studies was characterized by the radial growth rate Kr of about 300 μm/h and by the specific growth rate μ of about 0.100 h−1. Fungal biomass contained about 32% of crude protein in dry matter. The digestibility of this protein in vitro was close to 75%. Protein analysis for amino acids showed that the content of exogenous amino acids approached that in protein of the FAO standard. As a result of 34 — h culture of this strain in solid medium, net protein increased by about 5.0 g/100 g of starting medium d.m. at the cost of decomposition of about 20 g carbohydrates.
Acid‐mechanical, alkaline and enzymatic treatment of agricultural wastes to obtain substrate for microbiological conversion
Authors: Katkevich J. , Katkevich R. H. , Viesturs U. E. , Sakse A. K. , Leite M. P. 
Published: December 2004

AbstractThe present paper deals with almost wasteless technologies of pretreatment and obtaining of sugars and biomass from straw and potato tops. Several variants ensure a 1 t of straw per hour productivity using original auger reactors 290 and 150 mm in diameter. The authors have studied the submerged and solid state cultivation of various microorganisms applying the obtained substrates.
Some aspects of the initiation of callus and suspension cultures of Valeriana officinalis var. Diliana
Authors: Milkova E. , Panayotov Ch. , Atanassov A. 
Published: December 2004

AbstractNew developments in the aspect of plant tissue cultivation of an important pharmaceutical species are discussed. There are some pathways of production cell cultures of Valeriana officinalis on agar and liquid media. The aim is to obtain suspension cultures able to produce biological active substances of the group of valepotreates as well as some new substances eventually. We gave a morphological characteristic of the different aggregated and differentiated suspension cultures.
Characterization of biotechnological processes and products using high‐performance liquid chromatography (HPLC). III. Quantitative analysis of organic acids in the α‐ketoglutaric acid synthesis
Authors: Gey M. , Weissbrodt E. , Stottmeister U. 
Published: December 2004

AbstractA HPLC technique for the analysis of organic acids in the production of α‐ketoglutaric acid was developed. The method was applied and optimized for the quantitative determination of citric acid, pyruvic acid, isocitric acid and α‐ketoglutaric acid in fermentation solutions.As microorganism the yeast Yarrowia lipolytica and as substrates glucose or paraffins were used.The chromatographic separations were carried out by means of 50 and 100 × 8 mm i.d. glass columns packed with an anion‐exchange resin based on an 8% cross‐linked polystyrene‐divinylbenzene copolymer.The relative errors ranged from 2.1% (α‐ketoglutaric acid) to 5.2% (isocitric acid). The percent recovery values varied between 94.4% (isocitric acid) and 107.7% (pyruvic acid).The contents of organic acids in fermentation solutions after the microbial synthesis based on paraffins or glucose were compared.
New method for the characterization of the microbial growth in carrageenan gel
Authors: Marín‐Iniesta F. 
Published: December 2004

AbstractA method for the analysis of distributed growth of E. coli in k‐carrageenan gel is described. The method uses optical and electron microscopy to determine morphometric data of cell microcolonies in the gel, such as average microcolony volume, distance of microcolonies to gel surface and cell density in the microcolonies. Logarithmic equations describing the distribution of authentic values of volume occupied by cells in gels at different times of incubation were determined. With these equations it is possible to predict the quantitative distribution of cells in the gel and to define some parameters. These parameters can characterize the growth behaviour of the microbial strains in any particular culture condition and can be useful in the future search to improve the industrial applications of immobilized cells.
Influence of B‐vitamins and trace elements on lysine production by micrococcus varians 2Fa
Authors: Sen S. K. , Chatterjee S. P. 
Published: December 2004

AbstractA hydrocarbon utilizing strain of Micrococcus varians 2Fa isolated from local soil has been found to yield lysine 2.6 g l−1. Addition of B‐vitamins and trace elements to the optimal media, has been found to stimulate growth and enhance lysine yield.
The application of new aminoorganic silanes for affinity chromatography of plant peroxidases on vanillin‐liganded controlled porosity glass columns
Authors: Rogalski J. , Dawidowicz A. , Kapusta K. , Miedziak I. , Leonowicz A. 
Published: December 2004

AbstractIn this work, new packings consisting of home made controlled porosity glass, new self‐prepared aminoorganic silanes and vanillin as a ligand were used for affinity chromatography of some plant peroxidases (donor: H2O2 oxidoreductases; EC 1.11.1.7). The procedure allowed simple and relatively high purification of enzymes. The results were compared with those obtained with the material including commercially available γ‐aminopropyltriethoxysilane.
Comparative organic growth factor requirements of nine Candida species
Authors: Madan M. , Kamra N. 
Published: December 2004

AbstractNine Candida species isolated from fleshy fruits have been examined for their organic growth factor requirements. Complete or partial deficiencies for thiamine, biotin, pyridoxine, inositol, pantothenic acid, ascorbic acid and xanthine have been reported in C. catenuclta, C. curiosa, C. curvata, C. humicola, C. rhagii, C. steatolytica and C. tropicalis. Only two species, namely, C. fragicola and C. ishiwadea were prototrophic for the growth factors. Concentrations of essential growth factors higher than the optimum have been found inhibitory for the growth of yeasts.
Growth of pellets of a basidial fungus pleurotus ostreatus under various cultivation conditions
Authors: Styogantseva J. M. , Are R. J. , Viesturs U. E. 
Published: December 2004

AbstractStudies on the pelletization of fungus Pleurotus ostreatus have established the pellets to differ as to the size, density and chemical composition. Changes in the pellets, taking place during culture growth, are helpful in studying the mode of their development. We have studied various conditions of cultivation, and established the factors enhancing culture growth. Prehomogenization of seeds, velocity of stirrer revolution, partial pressure of dissolved oxygen and that of other factors was established to affect the structure of pellets and parameters of culture growth.
Konservierung von Mikroorganismen in Polyvinylalkohol
Authors: Riedel K. , Huber H. , Kühn M. 
Published: December 2004

AbstractA method is described for storage of microbial strains. The microorganisms are mixed with a 10% solution of polyvinylalcohol and stored at 4°C. It is demonstrated that most microbial strains studied remained uncharged were stable for 1 year.
Dynamics of redox potential in bacterial cultures growing on media containing different sources of carbon, energy and nitrogen
Authors: Oktyabrsky O. N. , Smirnova G. V. 
Published: December 2004

AbstractTwo kinds of redox‐potential changes were observed in batch cultures of E. coli, B. subtilis and B. megaterium with intensive aeration and pH maintenance at constant level: (i) a gradual decrease of the redox potential during continual bacterial growth as a result of interactions between platinum electrode and cell surface; (ii) the redox jumps in the generation of which the soluble redox substances take part under the conditions of different transitional processes (exhaustion of the sources of carbon, energy of nitrogen, metabolism switching from one source to another and so on). The redox monitoring may be useful for cultivation control in these situations.
Oxygen requirements of Aspergillus awamori fungi in the process of glucoamylase biosynthesis
Authors: Kostka G. , Ka̧czkowski J. 
Published: December 2004

AbstractThe oxygen requirements of Aspergillus awamori as well as the adaptation to it and the aeration of the cultivation medium were determined in the process of glucoamylase synthesis. Under the selected agitation and aeration conditions (impeller‐tip speed = 4.2 m/s; aeration 1.5 vvm) the cultivation‐medium aeration was analysed by means of dissolved‐oxygen‐concentration measurement during the course of the process. It was demonstrated that for obtaining the glucoamylase‐activity level of 800 U GA/cm3 under the selected conditions and with the fungus applied the dissolved‐oxygen concentration at the level of 25% saturation should be maintained. Those findings could serve as auxiliary indexes in the scale‐up process of glucoamylase synthesis.
Anwendung der p02‐Elektrode zur Gelöst‐Sauerstoff‐Bestimmung in Organischen Flüssigkeiten
Authors: Weichert D. , Klappach G. , Schröter H. 
Published: December 2004

AbstractThe method described allows the determination of dissolved oxygen in water‐inmiscible organic liquids under normal pressure in a temperature range of 0°C to 80°C depending on the boiling point of the organic material. The method can be adapted to modified conditions.The method using the principles of O2‐measurement by means of CLARK'S electrode offers an accuracy of 2–6%. The exact knowledge of dissolved molecular oxygen in organic liquids can be of interest for chemical or biotechnological processes.
Molecular basis of biodegradation of chloroaromatic compounds
Authors: Sangodkar U. M. X. , Aldrich T. L. , Haugland R. A. , Johnson J. , Rothmel R. K. , Chapman P. J. , Chakrabarty A. M. 
Published: December 2004

AbstractChlorinated aromatic hydrocarbons are widely used in industry and agriculture, and comprise the bulk of environmental pollutants. Although simple aromatic compounds are biodegradable by a variety of degradative pathways, their halogenated counterparts are more resistant to bacterial attack and often necessitate evolution of novel pathways. An understanding of such evolutionary processes is essential for developing genetically improved strains capable of mineralizing highly chlorinated compounds. This article provides an overview of the genetic aspects of dissimilation of chloroaromatic compounds and discusses the potential of gene manipulation to promote enhanced evolution of the degradative pathways.
Biosynthesis of protein by microscopic fungi in solid state fermentation. III. The effect of different cultivation methods and various media on protein biosynthesis by Aspergillus oryzae A. or. 11
Authors: Czajkowska D. , Ilnicka‐Olejniczak O. 
Published: December 2004

AbstractThe effect of the culture method in solid medium and the influence of starch‐containing raw materials on the yield of fungal protein biosynthesis were studied. Three procedures (laboratory bioreactor method, tray method and pile method) gave satisfactory results. Protein yields amounted to 5.0–5.9 g/100 g of starting medium d.m. upon utilization of 20.9–24.1 g carbohydrates. The procedure involving the use of a fermenter with a mixer afforded protein yields by about 50% lower as compared with the three above‐mentioned procedures, and therefore it requires technical improvement.As a result of fungal culture using various starch‐containing raw materials, the protein content in post‐culture products increased by 46–88%, as compared with starting medium. The contents of 13 amino acids (including some exogenous ones which increased by 52–82%) in post‐culture products substantially rose (by 34–63%). The post‐culture products exhibited proteolytic activity (1260–3500 HU/g of d.m.).The kind of the source of starch evidently influenced protein biosynthesis. Media based on potatoes afforded the greatest increases in protein (5.8–5.9 g/100 g of starting medium d.m.), and those containing coarse rye meal and milling by‐products — the smallest ones (4.5–4.6 g/100 g of starting medium d.m.).
Comparative determination of the rates of Kluyveromyces bulgaricus protoplast formation by the coulter counter technique and spectrophotometry
Authors: Van Huynh N. , van den Cruys K. , van Roey G. , Decleire M. 
Published: December 2004

AbstractKluyveromyces bulgaricus protoplast formation was studied by the determination of the remaining intact cells with the Coulter counter, the decrease of the absorbance of the cell suspension upon dilution into an hypoosmotic medium and the liberation of intracellular proteins after protoplast lysis. Due to the scattering of light by cells and ghosts, spectrophotometric readings were not enough specific and led to the underestimation of the reaction rates (about 40% less). The Coulter counter technique and the determination of the liberation of intracellular proteins gave the same rates over a large range of cell concentrations and in the presence of various cell lytic enzymes. The importance of corrected etermination of the time course of the reaction was illustrated by the good correlation obtained between protoplast formation and ATP turnover.