bluuebunny/crossref_metadata_2025 huggingface dataset:
The pretreatment effect on wheat straw saccharification
Authors: Stoyanov I. , Ilieva S. , Savov V. , Panayotov H. , Dineva J. , Spasova D.
Published: December 2004

Enzymatic 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

Anaerobic 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

The 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

From 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

A 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

Recombinant 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

Chymosin 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

S. 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

A 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

The 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

New 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

A 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

A 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

A 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

In 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

Nine 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

Studies 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

A 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

Two 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

The 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

The 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

Chlorinated 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

The 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

Kluyveromyces 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.
Assays of urea and arginase with a biocatalytic membrane electrode operating on conductimetric principle
Authors: Macholán L. , Filípek J. , Andrýs C.
Published: December 2004

A bioelectrode consisting of two parallel noble metal nets and a thin layer of gel‐entrapped urease between them permits to determine urea conductimetrically with a response time 3–5 min and reproducibility 5–6% above 60 micromolar concentration of urea. Differential measurement eliminates the interference due to conductive components of the real sample. Evidence has been obtained for extended application of the method by using immobilized microbial cells or tissue slice as biocatalyst in place of the immobilized purified enzyme. It is also suitable for simple kinetical assaying arginase activity in the tissue extracts.
Productivity of cultures from secondary colonies of streptomycetes producing anthracycline antibiotics
Authors: Igina E. F. , Tulemisova K. A. , Nikitina E. T.
Published: December 2004

At late stages of development of surface cultures streptomycetes producing anthracycline antibiotics were shown to form secondary colonies on PRIDHAM & GOTTLIEB'S medium with xylose. Stable variants obtained from them possessed an increased biological activity (by a factor of 2–3 times) due to the accumulation of amounts of antibiotically active anthracyclines.
New synthetic route to 9α‐hydroxy‐4‐androsten‐3,17‐dione
Authors: Uszycka‐Horawa T. , Skibińska M. , Jakubowski W.
Published: December 2004

The new synthesis of 9α‐hydroxy‐4‐androsten‐3,17‐dione from hydrocortisone is described. The six‐step reaction sequence involved degradation of the side chain, dehydration, ketals formation, reduction of the α‐epoxide to 9α‐hydroxyderivative and ketal groups cleavage. The overall yield is about 12%. Physico‐chemical data of two new compounds were determined.
Hollow fiber modules as a tool for enzyme and cell immobilization
Authors: Rucka M. , Sroka Z.
Published: December 2004

Owing to their properties, hollow fiber modules are attractive carriers for the immobilization of biocatalysts. Various systems and modes of operation are summarized and discussed.
Blasenfreie Begasung
Authors: Kopp Th.
Published: December 2004

Different methods of bubble‐free oxygenation are discussed. Today, the surface oxygenation has lost its importance. Technically, membrane oxygenation methods are used in various fermentervolumes although the construction principles are quite complicated. The scale‐up‐potential is here very limited. On the other hand, the CHEMCELL‐oxygenation is a simple method, safe in terms of sterility and applicable to all fermenter sizes common for cell culturing. A great benefit of this principle is that the amount of oxygenation is not dependent from the mixing parameters.
Prozeßsteuerung des O2‐Partialdruckes der Kulturlösung bei aeroben mikrobiellen Fermentationen
Authors: Grosse H. H. , Hilliger M. , Bormann E.‐J.
Published: December 2004

Following the introduction referring to the fundamental role of the oxygen supply and the meaning of measured values of diluted oxygen in liquid culture media commonly used strategies to avoid the oxygen limitation in aerated fermentations are summarized and validated with respect to their realization requirements. Furthermore, a new developed principle for the control of the p O2‐value based on the growth regulating influence of the acidity (pH‐value) without using the increase of the oxygen transport rate of the fermenter is discussed.
The principle of optimality as the foundation of biotechnological modeling
Authors: Prause M. , Kaiser J.
Published: December 2004

There are many points of contact between optimization problems and modeling. On the one hand the model adjustment process itself as a process of estimation is closely connected with optimization, in that it is to produce what is in one sense the best possible model. The basic structure of the optimization problem as problem in decision making with the necessary input of an objective function is thus evident. On the other hand a model is never an end in itself but on the basis of its simulation capacity a means to an end, for example in biotechnological optimization. From this point of view the model is a product of scientific work and thus an economic value. Equally, through its intended purpose the model exhibits a utility value. A complete evaluation of the model as a condition of rational modeling must take into account both these aspects. That is possible in principle by adding the modeling expenditure to expenditure for the realization of biotechnological processes, expressing the economic consequences of model quality as an objective function, and minimizing the specific total expenditure for the product to be produced.

Biotechnological practice requires that the “optimum” model is approached by means of iterative processes. Some practical examples will make the process clear, taking into account qualitative (semantic) and quantitative (accuracy) aspects of the utility value.
Production of high ethanol concentrations from glucose using a vertical rotating immobilized cell reactor of the bacterium zymomonas mobilis
Authors: Amin G. , Doelle H. W.
Published: December 2004

Long‐term continuous ethanol production of up to 80 g.l1 with a volumetric ethanol productivity of 63 g. l−1. h−1 was maintained for more than 72 days using a Vertical Rotating Immobilized Cell Reactor of the bacterium Z. mobilis. Continuous production of higher ethanol concentration was unsuccessful due to an inhibition of cell growth by long exposure to high ethanol concentrations. However, ethanol concentration as high as 120g. l−1 and volumetric ethanol productivity of 13g. l−1. h−1 were achieved in a repeated‐batch fermentation system using the same bioreactor. By a simple washing operation at the end of each run, immobilized biomass could be effectively regenerated and used to carry out more than 10 successive fermentation cycles.
Fructose phosphorylation by zymomonas mobilis glucokinase
Authors: Edye L. A. , Kositanont Ch. , Doelle H. W.
Published: December 2004

Zymomonas mobilis ATCC 53431, a fructokinase negative mutant is unable to utilize fructose as a sole carbon source for growth. At high fructose concentrations, however, fructose was converted to ethanol. The fructose uptake displayed MICHAELIS‐MENTEN kinetics with an apparent Km of 185 mM fructose.

Purified glucokinase from ATCC 53431 and the wild strain ATCC 29191 both exhibited fructose phosphorylating activity at high fructose concentrations with an apparent Km value of 222 mM fructose. Glucokinase substrate specificity was found not be absolute, as previously reported.
Outer membrane vesiculation of acinetobacter calcoaceticus
Authors: Borneleit P. , Kleber H.‐P. , Binder H.
Published: December 2004

For intact cells of A. calcoaceticus 69V susceptibility to hydrophobic agents (antibiotics, dyes) was established. The composition of its outer membrane and comparison with that of a reference strain, A. calcoaceticus CCM 5593 with a blocked hydrophobic pathway, gave no indication of phospholipid bilayer domains as the structural basis of these permeability characteristics. The outer membrane composition together with the data of time‐resolved fluorescence anisotropy measurements is indicative of a high state of order of the hydrocarbon region.

A. calcoaceticus 69V releases lipopolysaccharide (LPS)‐rich membrane vesicles into the growth medium when grown on a hydrophobic carbon source. While the cells contain both R‐form and S‐form LPS, the LPS released with the vesicles is exclusively of the R‐type. The same selectivity with respect to LPS composition was observed when LPS was removed from intact cells by EDTA‐NaCl treatment which leads to a break‐down of the barrier to hydrophobic agents in A. calcoaceticus CCM 5593.

We propose that due to its physical properties, R‐form LPS forms tightly packed structures within the membrane which, under certain conditions, become destabilized and liberated into the surrounding medium. As a consequence, a disturbance of the highly ordered lateral molecular arrangement might lead to altered permeability properties of the outer membrane as suggested in one of the two alternative models existing to explain permeability changes observed in deep rough mutant strains of Enterobacteriaceae.
Untersuchungen zur Oberfläuchenstruktur von Pasteurella multocida
Authors: Rosner H. , Rohrmann B. , Günther H.
Published: December 2004

Detailed studies of the surface structures are an important requirement for the development of efficient vaccines against enzootic pneumonia in calves and piglets caused by Pasteurella multocida.

Electron microscopical examination after Alcian Blue staining shows capsular material extending far into the surrounding medium.

The extent of the capsules depicted by light microscopy did not correlate with virulence and immunogenicity. However, the extent of the capsules was effected by different culture conditions.

The immunization with extract material resulted in a good protection against homologous infection.

It has been shown that different cultivation conditions can result in heterogeneity of LPS and in altered OMP‐profiles.
Adhesins of escherichia coli
Authors: Nimmich W.
Published: December 2004

E. coli has got increasing importance as a causative agent of intestinal and extra‐intestinal diseases. In both these infections adhesion of the bacteria to mucous surface cells are initial events for coionization and development of infection. Adhesins are bacterial recognition proteins which specifically interact with carbohydrate moieties of glycoproteins or glycolipids on mammalian cells. The adhesiveness of bacteria is associated with filamentous surface appendages, designated as fimbriae or pili, as well as with non‐fimbrial components. Some recent data on the nomenclature, classification, disease association, receptor specificity, and topographic arrangement are presented. The correlation between E. coli O : K : H serovar and fimbrial antigens is demonstrated on the basis of E. coli isolated from patients with urinary tract infections. Hitherto unknown non‐fimbrial adhesins are briefly described.
Untersuchungen zur in vitro‐ und in vivo‐Adhärenz von Bordetella bronchiseptica
Authors: Krüger M. , Nguyen A. T. , Horsch F. , Lux R.
Published: December 2004

Pathogenic strains of Bordetella bronchiseptica undergo phase changing under in vitro conditions. This is the irreversible loss of virulence factors. Adhesins are involved in these structures. They permit adhesion and colonization of bacteria to respiratory epitheliums. Phase III‐bacteria adhere as well as Phase I‐bacteria under in vitro conditions (cells of respiratory epithelium from guinea pigs).

Four phase III‐strains of seven isogenic pairs adhere in a significant higher number per cell than phase I‐agents. These results are confirmed by results of investigations with phase III‐strains constructed throughout cultivation on several culture media. Phase III‐bacteria colonize in significant lower numbers under in vivo conditions in rabbits and guinea pigs. Purin auxotrophic mutant strains colonize less in guinea pigs than in rabbits. In vitro adhesion does not reflect the real bacteria‐host interaction between adhesin and receptor.
Die gelenkte Biosynthese immunogener Strukturen für die Impfstoffproduktion am Beispiel Bordetella bronchiseptica
Authors: Kludas K.‐H.
Published: December 2004

It is described how Bordetella bronchiseptica forms biomass mainly from L‐glutamic acid and L‐proline. Glucose‐6‐P is prepared by gluconeogenesis with the aforesaid amino acids and by phosphorylization of starch by phosphorylase and cAMP serving as signal substance. Synthesis of the heatsensitive toxin is mainly effected by yeast extract and a trypton at low redox potential. The capsule is synthesized by nicotinic acid amide, peptides, glycerol, glucose, ascorbic acid, and Mn‐ions. The fimbria development is positively influenced by the taurine, L‐glutamic acid, L‐histidine, and polysaccharides, The necessary immunobiological parameters for vaccines are optimally developed by Bordetella bronchiseptica when observing the requirements for cultivation.
Amorphous‐cellulose dispersing activity of cellobiohydrolase I of trichoderma reesei, suggestion for an interpretation of the C1‐effect
Authors: Heitz H.‐J. , Witte K. , Wartenberg A.
Published: December 2004

Two isoenzymes of cellobiohydrolase I (CBHI/1 and CBHI/2) of Trichoderma reesei purified from CelluclastTM are shown to cause a new mode of reaction which is exhibited additionally to the known exo‐glucanase reaction of CBHI: Dispersion of amorphous cellulose solution is increased by CBHI/1 and CBHI/2 to 49 and 64 p.c., respectively, before decompositions of substrate as induced by the same enzymes become detectable. Amorphous‐cellulose dispersing activity of CBHI is reduced by cellobiose which is known to be an inhibitor of CBHI. Amorphous‐cellulose dispersing activity was also observed of a CBHII isoenzyme (CBHII/2), an endo‐glucanase and complete Celluclast, however, to lesser extents (17, 12, 35 p.c., respectively). Observations with a phase‐contrast microscope determined an increase of dispersion of particles of amorphous cellulose induced by cellulases of Celluclast. Decompositions of amorphous cellulose run almost linearly and quite exponentially when induced by CBHI and CBHII, respectively, allowing differentiation between exo‐glucanase and endo‐glucanase activities of these cellulases.
1‐acetyl‐β‐carboline, a new metabolite of streptomyces kasugaensis
Authors: Proksa B. , Uhrín D. , Šurdíková M. , Fuska J.
Published: December 2004

1‐Acetyl‐β‐carboline, isolated as a metabolite of an actinomycete for the first time, was obtained from the culture filtrate of Streptomyces kasugaensis. The separated compound was identified by spectral means. Production of 1‐acetyl‐β‐carboline was substantially rised after addition of equimolar amounts of DL‐tryptophan and DL‐alanine into the cultivation medium.
Purification and partial characterization of external and internal invertases from two strains of trichosporon adeninovorans
Authors: Büttner R. , Schubert U. , Bode R. , Birnbaum D.
Published: December 2004

We investigated the extracellular and intracellular invertase activity of two Trichosporon adeninovorans strains. Both strains (SBUG 724 and CBS 2844) secrete one invertase into the medium. The external enzymes were purified by chromatography on hydroxylapatite. The molecular weight of the external invertase of SBUG 724 was found to be 650,000 and of CBS 2844 450,000. The internal invertases were separated by DEAE‐cellulose chromatography. The molecular weight of the enzyme from CBS 2844 was estimated to be 125,000. In the strain SBUG 724 we found two internal invertases (Mr 230,000 and 70,000). The activity of all invertases has similar properties. The pH optimum of the reaction was determined between 5.0 and 5.2 and the temperature optimum was 60 to 70°C. The Km value for sucrose was determined to be 71 to 83 mM and for raffinosc 27 to 36 mM.
Ammonium‐nitrogen assimilation and nitrogen fixation in azospirillum lipoferum and azospirillum brasilense
Authors: Shawky B. T.
Published: December 2004

The effect of ammonium nitrogen on the growth and efficiency of nitrogen fixation by A. lipoferum and A. brasilense grown under various growth conditions was investigated.
Characterization of biotechnological processes and products using high‐performance liquid chromatography (HPLC) VI. Determination of lactic acid and short‐chain carboxylic acids C1–C5
Authors: Gey M. , Klossek P. , Becker U.
Published: December 2004

Lactic acid and short‐chain carboxylic acids C1–C5 were analyzed on an Aminex HPX‐87H column using UV and RI detection. The HPLC method was applied to complex fermentation media of a microbial lactic acid formation process. The resulting chromatograms of the yeast extract or culture medium showed some UV‐absorbing substances that interfered partially with peaks of short‐chain carboxylic acids.

In contrast to UV monitoring, RI detection gave only a few small peaks of these so‐called “background chromatograms”. Also glucose used as substrate could be quantified in the culture medium, because of which RI detection should be preferred.

Furthermore, a self‐prepared cation‐exchange resin (SAC = S‐DVB) based on a poly(styrenedivinylbenzene) partially comparable in its properties with Aminex resins was useful for fast (about 4 minutes) and not too expensive determinations of lactic and acetic acid in fermentation media.

Applying this separattion system to fermentation solutions detected by RI as well as UV monitoring results in the quantitative analysis of lactic acid kinetics identical with an Aminex HPX‐87H column were achieved.

Finally, the simplicity of lactic‐acid analysis is illustrated by examples of dairy products only centrifugated and diluted in double distilled water before injecting on a cation‐exchange column.
Accumulation of heavy metals by oscillatoria sp.
Authors: Bhattacharya D. N. , Ghosh R. , Pal S. C. , Sen S. K.
Published: December 2004

Microorganisms are the dominatign inhabitants of the soil, and there is an icnreasing tendency to apply heavy metals in agricultural practice. The ecological balance may be distrubed unknowingly if we do nogt measure the tolerance by the microorganisms of these heavy metals. It has been found in a Oscillatoria model system that widely used heavy metals have a high degree of toxicity to this cyanobacter.
Concentration of microorganisms in microbial suspensions
Authors: Pätz R.
Published: December 2004

For technical research and development with high cell densities the volume concentration plays an important role. On the basis of simple determinations of a density concentration relationship a method is described which allows a better calculation of the real density of biomass and of dry matter as used till now. As results of simple relations for spherical particles an average water content and the volume fraction may be derived.
Embryo manipulation – present and future
Authors: Plesník J. , Bulla J. , Bavin V.
Published: December 2004

The article presents a survey of the modern state, application, and prospect of development of present‐day biotechnological methods of intensification the animal production using existing large genetic potential of animals as well as of new genetically transformed animals by the method of introduction of the genetic material on one type or species organism into another one.

Recent succes in molecular biology, genetics, embryology and physiology of animal reproduction anables to influence purposefully the process of embryogenesis. In this connection, the role of mammalian embryotransfer method become even more prominent. It secures the final results and their evaluation following various effects on the embryo.
Biological plant protection
Authors: Kleinhempel H.
Published: December 2004

Breeding of high‐yielding varieties of cultivated plants has led to spectacular results in the past 30 years. Since the genetically fixed yield potential has been exhausted to a very large extent, it is necessary to take intensive plant protection measures in addition to ensuring high nutrient supply. Plant protection has made a highly recognized contribution to the impresssive development of yields in the last few decades.
Bakers' yeast mediated preparation of s (+)‐6‐methyl‐5‐hepten‐2‐ol, the pheromone of an ambrosia beetle
Authors: Kaminska J. , Markowicz L. , Stolowska J. , Gora J.
Published: December 2004

6‐Methyl‐5‐hepten‐2‐one was reduced in 64% yield to the title compound of > 90% enantiomeric excess by bakers' yeast which had been kept in aqueous ethanol under aerobic conditions in the absence of carbohydrates.
Methanol metabolism and ammonia assimilation in four methylophilns strains
Authors: Elrayes E. G. , Banat I. M. , Hamdan I. Y.
Published: December 2004

Methanol assimilation and dissimilation pathways and ammonia assimilation pathway were investigated in four obligate methanol‐utilizing bacteria through the detection of key enzymes. Both hexulose phosphate synthetase and hexulose phosphate isomerase, key enzymes of the ribulose monophosphate pathway (RMP) for methanol assimilation were detected whereas four key enzymes (hydroxy pyruvate reductase, isocitrate lyase, malyl‐CoA‐lyase and glyoxylate aminotransferase) that are characteristic of the serine assimilation pathway were absent. Key enzymes for the two methanol dissimilation pathways, the linear sequence enzymes formaldehyde and formate dehydrogenase and the RMP cyclic sequence enzymes glucose‐6‐phosphate dehydrogenase and 6‐phosphate giuconate dehydrogenase were all detected. Ammonia was assimilated via the glutamate dehydrogenase pathway and not via the glutamine synthetase and glutamate synthase pathway.
Spray drying of protein solutions concentrated by cross‐flow ultrafiltration
Authors: Mohr K. ‐H , Steube K. , Kleinschmidt Th.
Published: December 2004

The influence of various operating parameters as temperature, pressure, flux, solid content and operating time will be investigated for the concentration of protein solutions by ultrafiltration.

The spray‐drying mechanism of protein concentrates is discussed.
Improvement of the nutritional value of rye products by solid‐state fermentation with fusaria
Authors: Klappach G. , Weichert D. , Zakordonets D. A. , Suprun S. M. , Sholkevich Y. G.
Published: December 2004

The use of some cereals in animal nutrition, e.g. rye, is limited because of some constituents. By solid‐state fermentation using selected Fusaria it is possible to enhance the nutrition value and to enrich the fermented material with free and essential amino acids and vitamins. The fermentation method is described and the results of analytical assays are discussed.
Some approaches to adaptive control of fed‐batch culture of the cellobiase producer aspergillus japonicus
Authors: Ananjin V. M. , Komkov A. S. , Solovjeva I. V. , Boyev A. V. , Okunev O. N.
Published: December 2004

Biosynthesis of cellobiase by an Aspergillus japonicus culture under various modes of cultivation was studied using a fermenter‐computer system. Two modes of fed‐batch cultivation were developed: temperate and intensive. Both modes used the double algorithm of glucose supply based on the process control by the preset profile of CO2 concentration in exhaust gas and consumption of the pH stabilizing titrant. Intensive fed‐batch proved the most efficient mode: it maintained conditions for derepressed cellobiase Liosynthesis and decreased the carbon and energy limit for enzyme production. Intensive fed‐batch is, thus, the most adapted to cellobiase biosynthesis conditions and nutrient requirements of the producing culture.
Atp‐Dependent gold accumulation by living chlorella cells
Authors: Karamushka V. I. , Ulberg Z. R. , Gruzina T. G. , Dukhin A. S.
Published: December 2004

An effect of the Au(III) energy dependent concentration has been discovered by living Chlorella cells. The process is most intensive within the alkaline interval of pH, fading away in the dark, and is suppressed in the presence of arsenate (C ≧ 1 μM), fluorides (C ≧ 0.01 mM), sodium azide (1 mM), DCCD (10 μM), 2, 4‐dinitrophenol (0.1 mM). In the dark the process is stimulated by ATP (but not by ADP, or AMP). ATP also neutralizes NaN3 effect, but not that of DNP. An energy dependent Au(III) concentration is also observed for other green, blue‐green, and, red singlecell algae.
An aspergillus awamori mutant with enhanced glucoamylase activity
Authors: Witkowska‐Gwiazdowska A. , Ilnicka‐Olejniczak O. , Kostka G. , Czajkowska D.
Published: December 2004

The mutagenesis of a glucoamylase‐producing A. awamori strain yielded a mutant exhibiting an 80% increase in the level of the biosynthesis of this enzyme under liquid state fermentation conditions (LSF).
Silica carriers for immobilization of thermostable α‐amylase
Authors: Dobreva E. , Ivanova V.
Published: December 2004

The possibilities for immobilization of thermostable α‐amylase from Bacillus licheniformis 44MB82 on silica carriers activated by different methods have been studied. Immobilization on Ti(IV)‐activated CPG, Chromosorb P, quartz powder and pumice stone was sufficiently effective. The preparation immobilized on CPG showed a shift in pH and temperature‐profiles of enzyme action. They were found to be changed from pH 6,0–6,5 to pH 8,5 and from 90°C to 80°C, respectively, when compared to these parameters of the soluble enzyme. Immobilization leads to enhancement of thermostability. Possibilities for batchwise use of the immobilized preparation were established.
Chitin and its derivative as supports for immobilization of enzymes
Authors: Krajewska B.
Published: December 2004

The ideal enzyme support should show high affinity to proteins, availability of reactive groups for direct reactions with proteins or for chemical modifications, easiness of preparing in different physical forms, nontoxicity and physiological compatability if required (food industry, biomedicine), as well as low cost. Chitin and its derivatives fullfil most of these requirements. The paper reviews enzymes immobilized on chitin and its derivatives along with techniques applied for their immobilization.
Synergism of isoenzymes of cellobiohydrolase I and II of trichoderma reesei in hydrolysis of amorphous cellulose
Authors: Heithz H.‐J. , Witte K. , Wartenberg A.
Published: December 2004

Decompositions of amorphous cellulose induced by cellulases of Trichoderma reesei were evaluated from gradients at zero time of exponential functions which were fitted to nephelometrically measured values of turbidty of incubated solutions of cellulose [turbidity = A × exp (B × t)+ C [A, B, C = constants, t = time]]. Synergistic enhancements of decomposition of amorphous cellulose resulted in the range of 300 p.c. whenever of the two isoenzymes of cellobiohydrolase I of Trichoderma reesei (CBH I, being an exo‐glucanase) one was incubated together with one of the isoenzymes of CBH II (being really an endo‐glucanase). Accessibility of amorphous cellulose to enzymatic decomposition being calculated from the fitted function by the term (A/(A + C)) × 100 [p.c.] resulted for the CBH I isoenzymes and for the CBH II/1 in the range of 27 to 38 p.c. of the total substrate. Incubations of CBH II/1 in with CBH I/1 and CBH I/2 were followed by increases of accessibility to 85 and 87 p.c., respectively. CBH II/2 by itself caused a substrate accessibility in the range of 80 p.c., which increased to 96 p.c. when it was incubated together with CBH I/1 or CBH I/2. Amorphous cellulose dispersing activity (ACD activity) being evaluated from the fitted function by the term (A + C)/(Ac + Cc) × 100 [p.c.] (Ac + Cc × control turbidity at zero time) was not increased when a CBH I isoenzyme was incubated together with a CBH II isoenzyme. EG I, a convetional endo‐glucanase from Tr. reesei proved not to act synergistically in any case when incubated together with one of the CBH isoenzymes. On the contrary, EG I turned out to act antagonistically to CBH II/1 and CBH II/2. Results can be interpreted as an exo‐endo‐synergism taking place between C1‐specific exo‐ and endo‐glucanases.
Isolation of biosurfactant‐producing bacteria, product characterization, and evaluation
Authors: Abu‐Ruwaida A. S. , Banat I. M. , Haditirto S. , Salem A. , Kadri M.
Published: December 2004

A gram‐positive, nonfermentative, rod‐shaped bacterium designated ST‐5, identified as Rhodococcus, was isolated from Kuwait soil. Grown on hydrocarbon, such as kerosene and n‐paraffin, the bacterium produced surface‐active compounds (biosurfactants). Measurements of surface tension, critical micelle dilution and emulsifying activity indicated that the biosurfactant is produced as a primary metabolite. The ST‐5 culture surface‐active component is mainly glycolipid in nature. Whole‐culture broth dropped surface tension to values below 27 mN/m and was stable during exposure to high salinity (10% NaCl), elevated temperatures (120°C for 15 min) and a wide range of pH values. The culture broth was effective in recovering up to 86% of the residual oil from oil‐saturated sand packs, indicating potential value in enhanced oil‐recovery processes.