bluuebunny/crossref_metadata_2025 huggingface dataset:
Production of Lipids and Carotinoids by Yellow Streptomyces (in Russian)
Authors: Kosyritzkaya W. E. , Andreyuk E. I.
Published: December 2004

The ability of yellow streptomyces to synthesize lipids and carotinoids was examined.

It has been established that the content of lipids in the mycelium varied from 9.7 to 57.1% depending on the species and the strains. Cultures belonging to the species Str. nephtigulosus, Str. ambofaciens, Str. citreus showed carotene‐synthesizing abilities. In the content of the lipids and carotinoids of the examined cultures were found our fractions possessing biological activity. The fatty acid content of the examined cultures was characterized by the saturated and unsaturated acids containing an even and odd amount of the carbon atoms (from C11 to C18) and a normal and branched chain (iso‐C16 and iso‐C17).
Vergleichscharakteristik von Isolaten der Gesamteweiße der Hefe in Abhängigkeit von den Bedingungen ihrer Abscheidung
Authors: Sergeev V. A. , Soloˇsenko V. M. , Bezrukov M. G. , Saporovskaja M. B.
Published: December 2004

Investigations are made about the possibilities of extraction of components included in the biomass of the yeast Saccharomyces cerevisiae after cell desintegration in dependence of the pH of the medium. Furthermore is shown the racemization of some amino acids during alcaline treatment of the desintegrated material during the isolation of the protien.
Streulichtphotometer zur kontinuierlichen Bestimmung der Biomassekonzentration in Fermentationsmedien
Authors: Geppert G. , Thielemann H.
Published: December 2004

After a short review of methods for the determination of the biomass concentration in fermentation broths the construction and working principle of a newly developed retroreflective photometer are described. The main advantages of the instrument are a wide range from 0.1 to 200 g biomass/l the sterilizability, the self‐cleaning of the cuvette‐window, a favourable design and a little maintenance. The device may be used directly at a fermenter to get a continuous singal or for measurement of single samples in the laboratory. The calibration curves are nearly linear in a wide range.
Evaluation of newer methods of pretreatment for biological utilization of cellulosic residues
Authors: Cabello A. , Conde J.
Published: December 2004

An evaluation of different kinds of treatments to enhance the biological degradability of sugarcane bagasse‐pith is presented. NaOH treatment, gamma ray irradiation and inoculation of the material with the white rotting mold Sporotrichum pulvurulentum and combinations of above mentioned alternatives were evaluated by measuring the increase in water solubility and the susceptibility to cellulose degradation as well as by the change in the chemical composition of the material.

NaOH treatment at 6% concentration and the combined treatment with NaOH at 2% and further fermentation with the mold gave the best results. Gamma irradiation up to a dose of 60 Mrad didn't show an important effect.
Thermophilic anaerobic digestion for sewage sludge stabilization
Authors: Hamer G. , Bryers J. D. , Berger J.
Published: December 2004

The microbially mediated biochemical reactions that occur during anaerobic digestion processes for methane production from soluble carbon energy substrates are well known, but in spite of this, the interactions within the multi‐species cultures responsible for the overall process require more detailed elucidation. When the process feed comprises mixed, solid, carbon energy substrates, as in the case of waste sewage sludge stabilization, many aspects of both the process biochemistry and microbiology are unresolved. This mini‐review seeks to identify some of these unresolved questions, particularly with respect to operation at thermophilic temperatures.
Biodegradability of swine effluents II. Kinetics of pollutants removal
Authors: Oliveira J. S. , Costa M. L. , Rodrigues A. , Menezes J. G. A. , Borié M. C.
Published: December 2004

Some aspects of the kinetics of bioremoval of pollutants during biodegradation of swine‐breeding waste waters are studied and a biphasic model is proposed. The concentration of nitrogen and phosphorus compounds during the process is followed. Following a previous contribution on the same subject, the aspects of dilution of those effluents are discussed, and it is proposed to treat raw effluents, in spite of the reduction of possible biostatic actions. Dilution will be acceptable only if strong inhibitory effects are observed.
Modellierung der enzymatischen Cellobiosehydrolyse – Vergleich linearer und nichtlinearer Parameterbestimmung
Authors: Bauer F. , Kude J.
Published: December 2004

Experimental kinetic data (initial rate and high conversion) on the hydrolysis of cellobiose by 1,4‐β‐glucosidace (Gliocladium sp.) have been analysed and a competitive inhibition by glucose has been proposed. The determination of kinetic parameters from integral data is based upon algorithms for non‐linear optimization and numerical integration. The values of kinetic constants \documentclass{article}\pagestyle{empty}\begin{document}$(v_{\max } = 1.02\frac{{\mu {\rm M}_{{\rm glucose}} }}{{{\rm mg}_{{\rm protein}} \cdot \min }},K_M = 2.6{\rm mM/l, and }K_P = 1.2{\rm mM/l)}$\end{document} agree well with the initialrate results. An important distinction is the confidence limit of parameters. Linear regression analysis shows a virtual accuracy and can lead to wrong conclusions.
Untersuchungen zur Thermostabilität immobilisierter Invertase
Authors: Mansfeld J. , Schellenberger A.
Published: December 2004

Invertase from baker's yeast (Saccharomyces cerevisiae) was covalently bound via glutaraldehyde to a macroporous polystyrene anion‐exchanger, silica, and porous glass. The thermal stability of the enzyme‐matrix complexes was found to be higher than that of soluble invertase, increasing in the order given above.

The immobilization of invertase to the polystyrene anion‐exchanger by benzoquinonen and trichlorotriazine provided enzyme derivatives with lower thermal stability compared to the soluble enzyme.

The thermal inactivation of all invertase‐matrix complexes is characterized by a biphasic course. The inactivation process is well described by a model of ULBRICH and SCHELLENBERGER [1] which is based on the assumption of two differently stable enzyme fractions each of which being inactivated by a first‐order reaction. This model proved to be appropriate also for the description of the thermal inactivation in the presence of substrate.
Gas balance method for testing of microbial growth efficiency after carbon substrate pulse
Authors: Baburin L. A. , Shvinka I. E. , Ruklisha M. P. , Viesturs U. E.
Published: December 2004

The present paper deals with the analysis of the amount of oxygen utilized for oxidation of a small dose of carbon substrate in carbon limited Brevibacterium flavum culture. The ratio of the measured oxygen consumption (mo2) to the amount of added carbon substrate (ms) gives a stoichiometric coefficient of the biological oxidation equation. A linear relationship between mo2 and ms was observed. To compare the efficiency of different carbon substrate utilization there has been introduced a normalized value β = m/m. There exists a simple relationship between β and the thermodynamical growth efficiency η The theoretical considerations are proved by experimental results with β, η and Yx/s in a chemostat culture at various medium flow rates.
Der substratlimitierte pH‐Auxostat – Eine neue Methode zur kontinuierlichen Kultur
Authors: Büttner R. , Uebel B. , Genz I.
Published: December 2004

A method for continuous cultivation of microorganisms is demonstrated, the substrate limited pH‐auxostat. The limiting substrate only is added with constant velocity. In this culture the cells grow with high utilization of the limiting substrate and with the highest specific growth rate possible at the given conditions. Yield coefficients and dilution rates of stable K+‐limited steady states in yeast cultures with different pH‐values and biomass concentrations were measured.
Autolysis of disintegrated cells of the yeast saccharomyces cerevisiae
Authors: Běehalová B. , Beran K.
Published: December 2004

Optimum conditions for autolysis of disintegrated cells of S. cerevisiae are at 50–53°C and pH 5.5; the process is terminated after 6 h. In the presence of sodium chloride (3–5%) the autolysis is complete after 5 h. The yield of autolysis of disintegrated yeast cells is about 70% of autolytic product per yeast dry weight. The product obtained after centrifugation, filtration and drying has very good sensoric and physical properties.
Zur Gewinnung von Ubichinon‐10 aus Acetobacter methanolicus IMET B 346
Authors: Worbs M. , Voigt B.
Published: December 2004

Mixtures of acetone/water (93 : 7 ··· 90 : 10, v/v) are favoured solvents for the extraction of ubiquinone‐10 from Acetobacter methanolicus IMET B 346. Using these solvent mixtures ubiquinone‐10 was extracted nearly completely. Other lipids were extracted partially. Extracts were obtained by optimal conditions with a ubiquinone content > 5%.
Microbial recycling of mineral waste products
Authors: Bosecker K.
Published: December 2004

The applicability of biotechnological methods to metal recovery from non‐sulfide industrial waste products (slag, galvanic sludge, filter‐press residue, filter dust, and fly ash) was investigated. From some products, copper, chromium, zinc or vanadium were completely extracted by sulfuric acid produced by Thiobacillus thiooxidans. The efficiency of bacterial metal solubilization varied depending on the type of waste material and on the pulp density. Stepwise increase of pulp density promoted bacterial growth and activity, resulting in metal concentrations of 6.6 g Cu/l, 6.3 g V/l, 24.4 g Zn/l or 21 g Cr/l in the leaching medium. In some cases bacterial leaching was as effective as chemical leaching with sulfuric acid. The efficiency of both processes is considered. In principal, bacterial metal recovery from industrial waste products seems to be feasible and may contribute to an increase in future supplies of raw materials, as well as to detoxification of industrial waste products resulting in reduced environmental pollution problems.
High performance liquid chromatography and biotechnological application of several oxidoreductases
Authors: Kovář J.
Published: December 2004

This paper describes our experience with the use of high performance liquid chromatography in the analysis and preparation of several NAD‐dependent dehydrogenases and oxygen‐dependent oxidases. The chromatographic materials tested were from Pharmacia (Sweden), LKB (Sweden) and Lachema (Czechoslovakia), the columns were attached to the fast protein liquid chromatographic (FPLC) system from Pharmacia. The preparative use of high performance ion exchange, molecular sieve and hydrophobic interaction chromatographies as well as of chromatofocusing made it possible to prepare tens of milligrams of completely pure enzymes in several hours. In most cases a combination of two high performance methods was sufficient to yield a homogeneous enzyme. The purified enzymes were used as analytical reagents for determining the concentrations of several metabolites and activities of some enzymes. A biotechnological application of immobilized alcohol dehydrogenase for the production of reduced nicotineadenine dinucleotide from the oxidized form of the coenzyme is discussed in a greater detail.
Ratio of heat production to oxygen consumption during the cell cycle of candida maltosa EH 15 grown on ethanol
Authors: Minkevich I. G. , Baumann F. , Rogge G. , Heinritz B.
Published: December 2004

The experimental technique for measurement of microbial culture heat evolution directly in fermenter has been described and its correctness analysed. Heat‐to‐oxygen ratio, Q0, of synchronized yeast culture in the absence of fermentative metabolism has been found to be practically independent of a cell cycle phase and close to the theoretical constant predicted by the mass‐energy balance theory. The collection of literature data on the heat‐to‐oxygen ratio is given. Energetic properties of cell biomass are discussed on the basis of the obtained and the surveyed values of Q0.
O‐acetyl cleavage by arthrobacter citreus
Authors: Fuska J. , Khandlová A. , Šturdíková M. , Proksa B.
Published: December 2004

Ability of deacetylation of Arthrobacter citreus (ATCC 11 624) was studied on three different types of substrates: 4,27‐Di‐O‐acetyl‐withaferin A, calycotomine derivatives and isoindolo/1,2‐b//3/benz‐azepine‐5‐one derivative. Only O‐acetyl groups were cleaved by this strain, N‐acetyl group was not attacked. This deacetylation was not regioselective; by hydrolysis of racemic acetates there was only slight stereospecificity observed. As this reaction took a short time and afforded high yields under moderate conditions it may be useful in organic chemistry and/or in the structure elucidation of natural products.
Immobilization of glucoamylase on porous glass
Authors: Miller E. , Sugier H.
Published: December 2004

The kinetic properties of glucoamylase immobilized on silanized porous glass in saccharification of starch solutions were examined as well as the influence of the working condition on its operational stability.
Biosynthesis of protein by microscopic fungi in solid state fermentation. II. Optimization of aspergillus oryzae A. or. 11 cultivation for protein enrichment of starchy raw materials
Authors: Czajkowska D. , Ilnicka‐Olejniczak O.
Published: December 2004

Study was made of the effect of medium humidity, source and dose of nitrogen, dose of phosphorus, dose of inoculum and aeration on protein biosynthesis by strain Aspergillus oryzae A. or. 11 in solid state fermentation. It was found that for a maximal protein yield the medium ought to contain about: 60% of water, 36% of starchy raw materials d. m. (e.g. 28.8% of coarse rye meal and 7.2% of beet pulp), 0.85% of nitrogen sources (1.6% of (NH4)2SO4 and 1.1% of urea), and 0.35% of phosphorus source (1.3% of KH2PO4). pH of medium should be near 6.5. The dose of inoculum should not be lower than 108 spores/100 g medium.

The duration of culture ought to be 20–22 h at 30–35°C, with aeration at least 40 dm3 of air/h × 1000 g medium. Under these conditions the protein yield is about 6.0–6.3 g/100 g of starting medium d.m. at the cost of utilization of about 25 g total carbohydrates.
The effect of culture conditions on proteolytic productivity of lipolytic microorganism
Authors: Maliszewska I. , Sroka Z.
Published: December 2004

The best proteolytic productivity of Pseudomonas fluorescens was observed when maltose and 5% peptone were in the medium. The optimal temperature was found to be 28°C.

The pH values in the range of 4.0 to 8.6 have not influenced the enzyme production.

The best proteinase cell activity (A) was in the early stage of culture (24–48 hours).
A comparison between the fermentative activities of free and Ca‐alginate‐entrapped cells of saccharomyces cerevisiae
Authors: Richter K. , Rühlemann I. , Becker U. , Berger R.
Published: December 2004

The continuous ethanol production by free and Ca‐alginate‐entrapped cells of the yeast Saccharomyces cer. IBT H 191 was investigated in a membrane reactor and in a CSTR, respectively. An empiric productivity model for free‐cell fermentation was found to be valid for immobilized cells if no external diffusion resistance existed within the reactor. In such a case the fermentative power of the immobilized cells was identical with this one of the free cells. A change of the ethanol‐tolerance behaviour of the cells as a result of the cell‐immobilization did not occur.
Construction of a promoter‐probe vector for the methanol‐utilizing bacterium acetobacter methanolicus MB 58
Authors: Schröder R. , Engel J. , Chistoserdov A. Y. , Tsygankov Y. D.
Published: December 2004

We report here the construction of a promoter‐probe vector, pRS2, which can be utilized in either Acetobacter methanolicus MB 58 or Escherichia coli due to the presence of broad‐host‐range replicon RSF 1010. The vector provides several unique restriction sites for promoter cloning as well as resistance markers for the selection of transformants. The promoter‐probe vector was constructed by inserting an EcoRI‐SalI‐polylinker fragment of pUC 19 into EcoRI/SalI digested pMK 16. The resulting plasmid, pRS1, was cloned into the unique EcoRI site of the broad‐host‐range plasmid RSF 1010.

The vector was used to clone promoter‐containing sequences derived from the A. methanolicus MB 58 chromosome as well as the E. coli lac‐promoter.
Immobilization of enzymes on porous silica supports
Authors: Łobarzewski J. , Wojcik A. , Błaszczynska T.
Published: December 2004

Four silica supports differing in pore dimensions were activated by treatment with SiCl4 and then with ethylenediamine to obtain alkylamine groups on the silica surface. Three enzymes, peroxidase from cabbage, glucoamylase from Aspergillus niger C and urease from soybean were immobilized on these supports using glutaraldehyde as coupling agent. It was found that the protein content, the retained enzymatic activity and the storage stability of the silica supported enzymes were considerably affected by support pore size and enzyme molecular weight, the factors which are supposed to alter protein distribution inside the support pores. The highest activity was found for peroxidase and glucoamylase attached to the silica with the widest pores, but their loss in activity during storage was considerable. The urease retained less activity after immobilization, but its storage stability was excellent.
Insoluble chromolytic substrates for the determination of proteolytic activity
Authors: Šafařík I.
Published: December 2004

New insoluble chromolytic substrates for the determination of proteolytic activity were prepared by incorporation of dyed proteins into the structure of calcium sulphate dihydrate. The prepared substrates could detect approximately 0.25–1.0 μg of trypsin per ml. The spontaneous leakage of dyed substances in water solutions was negligible.
The effects of some inorganic salts on the ethanol fermentation of Juniper berry sugars
Authors: Veljković V. B. , Lazić M. L. , Rutić D. J. , Stanković M. Z.
Published: December 2004

Ammonium and phosphate ions added to water extracts of juniper berries in optimum concentrations of about 70 and 35 mM, respectively, ensure a maximum ethanol yield of about 90% of the theoretical one in 16–18 hour fermentation. Magnesium ions have a slightly negative effect on the ethanol yield.
Gerätesystem zur Massenspektrometrischen Prozeßüberwachung in der Fermentationstechnik
Authors: Iske U. , Schön G. , Jechorek M. , Rost H.‐J.
Published: December 2004

A quadrupol mass spectrometer QMS c 300 developed and manufactured from the workshops of the Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen, has been cuppled with a 12 l laboratory steril fermenter. The QMS apparatus is provided with 3 different possibilities for sampling. Via a dynamic air input system the discharged air of the fermenter can be analyzed continuously. The static sampling input allows the off‐line measurement of gaseous and volatile compounds. Special membran samplers are used for measurements of volatile and gaseous substrates and microbial metabolites in the fermentation broth. The samplers can be adopted in the reactor vessel directly analogous to the pH and pO2‐electrodes.
Prozeßtechnische Untersuchungen zur Ausschöpfung mikrobieller Leistungsgrenzen
Authors: Pöhland D. , Klappach G. , Hühn J. , Schurig K.‐H.
Published: December 2004

The knowledge of the upper limits of growth rate and cell density is necessary to define the maximum possible productivity of a growth process. After a brief survey of the theoretical basis of microbial growth in dependence of mass transfer of oxygen and rheological properties of fermentation medium recent experimental results on the influence of higher pressure in the fermenter, of different substrate and dissolved oxygen concentrations on growth rate and yield coefficients of methanol utilizing bacteria are presented. Also some correlations between cell concentration and viscosity of fermentation broth are considered.
Quasikontinuierliche Bestimmung der Alkoholkonzentration in Fermentationsmedien
Authors: Geppert G. , Hanschmann G. , Thielemann H.
Published: December 2004

A measuring device for the quasicontinuous determination of volatile substances in aqueous liquids, especially alcohols (methanol or ethanol) in fermentation media is presented. The working principle and the construction of this instrument are described. Measurements are possible in a concentration range between 0.1 and 150 g/l. The measuring device is suited for industrial processes as well as for laboratory use.
Isolation of auxotrophic mutants and development of conjugation system in KISR methylotrophs
Authors: Kadri M. , Al‐Salameen F. , Haditirto S. , Engel J.
Published: December 2004

Isolation of auxotrophic mutants and conjugal transfer of plasmids are successfully demonstrated in four obligate methylotrophic strains isolated at Kuwait Institute for Scientific Research (KISR)Out of 11 auxotrophic, mutants, three required methionine and two leucine. Complete transfer of plasmid R68.45 from Pseudomonasto KISR methylotrophs and vice versa have been achieved with a low transfer rate.
Role of biotechnology in the sphere of veterinary vaccine products
Authors: Sólyom F.
Published: December 2004

During the last century two kinds of methods were developed in the field of vaccine production: those of inactivated and of attenuated vaccines. Both of them contained the whole microorganism. Thus, postvaccinal lesion even sporadically might occur. In the last 15 years, due to the development of molecular biology and of genetic engineering, novel technologies of vaccine production dissimilar to the former ones were and are evolved, which are as follows: subunit, synthetic, recombinant, genetically engineered and anti‐idiotype vaccines. Apart from genetically engineered vaccine, vaccines produced by means of new methods contain merely the immunocompetent protein particle of microorganism, thus, postvaccinal lesion should not be expected using vaccines of these kind. Vaccines produced by means of primary biotechnologic methods were put on the market in 1983 and introduction of 25 to 30 vaccines is expected until 1992. Approximately 145 companies, institutes are dealing worldwide with development of veterinary vaccines and they are in competition, with enormous investment capital, for accession of share as much as possible in vaccine market of about 550 million dollars.
Investigation of the connection between the electrophoretic mobility (EPM) of microorganisms and their capability of metal uptake
Authors: Iske U. , Hübner K. , Herold W.
Published: December 2004

The electrophoretic mobility of microorganisms (EPM) as a measure of their electric surface charge was determined as a function of different milieu conditions with the aid of the “Parmoquant 2” cell electrophoresis apparatus manufactured by CARL ZEISS Jena.

The object of these researches was to examine the influence of the electric surface charge of microorganisms on their metal loading capacity. The results show a direct correlation between the electric surface charge or the EPM of microorganisms and their maximum metal loading capacity. Cells with a high negative surface also posses a high metal binding capacity. On the other side only a negligible metal uptake can be observed at the isoelectric point of the microorganisms (EPM = 0). The method of cell electrophoresis proved suitable to analyze complex interactions between microorganisms and heavy metal ions.
Influence of cytochrome composition on the energy conservation of acinetobacter calcoaceticus 69‐V
Authors: Loffhagen N. , Babel W.
Published: December 2004

Acinetobacter calcoaceticus 69‐V contained cytochromes b, o, d and traces of cytochrome a1 after growth on ethanol. Cytochromes o, d, and a1 are known to be potentially capable of functioning as terminal oxidases. After growth on acetate only smaller amounts of cytochromes b and o were detectable. Cytochrome spectra of acetate plus glucose‐grown cells resembled more those of ethanolgrown cells. Cytochrome spectra of acetate plus ethanol‐grown cells were more similar to those of acetate‐grown cells but already showed small amounts of cytochrome d.

Ethanol‐grown cells were energized only by the oxidation of glucose. But the velocity of ATP synthesis was so low that the P/O quotient amounted to practically zero. The stoichiometries of ATP synthesis of the otherwise‐grown cells were generally higher for the oxidation of glucose than for the oxidations of succinate and D‐lactate. Similar high P/O quotients were measured for the oxidations of glucose and ethanol in acetate plus ethanol‐grown cells.

No significant energization could be observed during the oxidations of gluconate and acetate.

The findings indicate that electrons delivered by the PQQ‐dependent glucose as well as by NAD+‐ dependent ethanol oxidations have probably a common place of entry into the respiratory chain. Glucose and NADH appeared to be energetically equivalent although at least two energetically different pathways might be involved in substrate oxidation.
Energy balance in solid state fermentation processes
Authors: Leön Rodriguez , Torres J. A. , Echevarrí J. , Saura G.
Published: December 2004

It was applied a macroscopic energy balance to a solid state fermentation process and an electron balance in order to estimate the temperature and the heat evolved in the process. There were employed several equations that describe the development of the system and offer the possibility to design or control such fermentations.
Introduction of the tac‐promoter by lactose under fermentation conditions
Authors: Neubauer P. , Wolff C. , Hecker M. , Hofmann K. , Meyer L. , Kruschke P. , Heinrich H. W.
Published: December 2004

The use of the expensive IPTG for induction of the tac‐promoter is not practicable at the industrial scale because of the large amounts necessary for induction. We developed a system in which IPTG as inducer was replaced by lactose which induces the tac‐promoter with the same efficiency. In E. coli CW3011 (pOF1.0) lactose is utilized as inducer and carbon source even in the presence of glucose, presumably as a consequence of the overproduction of lac‐permease.
Purification and characterization of chorismate mutase isoenzymes from ruta graveolens l.
Authors: Hertel S. C. , Hieke M. , Gröuger D.
Published: December 2004

Two isoenzymes of chorismate mutase (EC 5.4.99.5), designated as CM‐1 and CM‐2, were isolated and partially purified from suspension‐cultured cells of Ruta gravelens by DEAE‐sephacel chromatography and gel filtration. 60–72% of the total activity measured after DEAE‐sephacel chromatography were obtained as CM‐1 and 28–40% were CM‐2 activity. CM‐1 was inhibited by phenylalanine (K1 = 4 · 10−6 M) and tyrosine (K1 = 8. 10−6M) and activated by tryptophan. In contrast, CM‐2 was not influenced by these three amino acids. The molecular weights estimated by gel filtration on SEPHADEX G‐150 were 56000 for CM‐1 and 45000 for CM‐2, respectively. Both isoenzymes were stable at −20°C, but exhibited different behaviour during thermal inactivation and different optima of reaction temperature. CM‐1 catalysed the reaction at a pH optimum of pH 7.8 and CM‐2 showed a broad optimum between 6–10. The Km‐values for chorismic acid were determined to be 1.1 mM for CM‐1 and 0.5 mM for CM‐2. The isoenzymes showed different behaviour to inhibitors of sulfhydryl groups. There were no differences in all parameters of chorismate mutase examined for two various cell lines of Ruta graveolens.
The nad‐dependent alcohol dehydrogenase of methylotrophic yeasts – an electrophoretic study (i)
Authors: Steudel A. , Nitzsche C.
Published: December 2004

The occurence of multiple forms of alcohol dehydrogenase (ADH) in methylotrophic yeasts is known from the literture. But no systematic work has been done to characterize these enzymes in detail. The aim of this work was to establish a suitable electrophoretic method for visualization of the ADH‐patterns of these organisms. It was found that the recovery of the enzyme activity during polyacrylamide gel electrophoresis (PAGE) depends on the composition of the gel buffer. The ADH of five different methylotrophic yeasts from the genera Candida, Pichia and Hansenula were analyzed. Every investigated organism shows rather complex ADH‐patterns.
Glucose influenced degradation of α‐santonin in pseudomonas sp. strain S (ATCC 43388)
Authors: Sangodkar U. M. X. , Mavinkubve S.
Published: December 2004

Pseudomonas sp., strain S ATCC 43 388 utilizes α‐santonin by inducible enzyme system measurable by oxygen uptake. Cells grown on acetate or benzoate show negligible oxygen consumption with α‐santonin. However, glucose grown cells show evidence of a rapid induction of santonin utilizing enzyme system indicating the implication of glucose or its metabolites in the regulation of degradation of santonin. As a consequence, growth of strain S on mixtures of glucose and α‐santonin occurs at rates higher than on either of the substrates alone. Mutants with lesion in the glucose metabolism, independent of α‐santonin degradation, fail to exhibit higher growth rates with the binary substrates. The results infer simultaneous metabolism of substrates.
Use of membrane operation for refining gibberellinic acid
Authors: Leonhardt H. ‐W. , Paul D.
Published: December 2004

Synthetic membranes are increasingly used in biotechnology. The possibilities of influencing the performance by membrane operation and changing the performance by physical modification were discussed. With cellulose‐2,5‐acetate membranes it was shown that the modification leads to an increase in the concentration of gibberellinic acid.
Protein enrichment in plant by fusaria
Authors: Weichert D. , Zakordonets L. , Klappach G. , Charkevitch E. , Koval E. Z.
Published: December 2004

Five micro fungi of the type Fusaria were investigated for the bioconversion of agricultural piant wastes. One strain was favoured for protein enrichment in heat‐pretreated straw, also improving digestibility in the fodder produced. The influence of the chitin content in the fodder was studied, and for calculating raw‐protein from the organic nitrogen content an additional factor of 0.92 was proposed to the known factor of 6.25. For the application of Fusaria strains in bioconversion processes a prognosis a prognosis was offered.
Production of Lipase by Yarrowia lipolytica, I. Lipases from Yeasts (Review)
Authors: Hadeball W.
Published: December 2004

In this paper a review is given about the most important lipase‐producing yeasts as well as the yield of lipase production. In order to find out the optimal conditions for lipase production by yeasts, it is necessary to investigate the influence of the main factors affecting lipase synthesis such as carbon and nitrogen sources, activators and inhibitors, interface‐affecting agents, temperature, pH and inoculum. Besides the yield of lipase as an efficiency factor of fermentation and the substrate specificity of lipase, playing an important role in applications, are described.
Homocitrate production by a lysine‐requiring pichia guilliermondii mutant
Authors: Schmidt H. , Bode R. , Birnbaum D.
Published: December 2004

Mutants of Pichia guilliermondii were isolated that lacked homoaconitate hydratase (lys4), homoisocitrate dehydrogenase (lys10) or α‐aminoadipate reductase (lys2) and were able to excrete homocitrate into the culture medium. The effects of incubation time and lysine concentration in the medium on the excretion of homocitrate were examined. In the presence of 600 mg of L‐lysine/1 in a minimum salt medium P. guilliermondii G75 (lys2) produced about 280 mg homocitrate/1 during 48 h of growth. A simple procedure to isolate homocitrate from the medium is described.
Phytic acid content reduction in canola meal by various microorganisms in a solid state fermentation process
Authors: Nair V. C. , Duvnjak Z.
Published: December 2004

Solid state fermentation of canola meal has been carried out for the reduction of its phytic acid content using the following microorganisms: Rhizopus oligosporus NRRL 2990, Aspergillus niger NRC 5765 and NRC 401 121, Aspergillus ficuum NRRL 3135 and a wild Saccharomyces cerevisiae strain.

The results showed that all these microorganisms can be used for the reduction of the phytic acid content in the tested material. A. ficuum which completely hydrolyzed the phytic acid in 48 hours was the most efficient.

Buffered systems, aeration and an increase in inoculum concentration caused faster and higher reduction of phytic acid content in canola meal.
Some kinetic studies on ribonucleosides degradation by extracts of penicillium citrinum
Authors: Allam A. M. , Elzainy T. A. , Elsayed M. A. , Elshafei A. M.
Published: December 2004

Cell‐free extracts of 3–4 days old mats of nitrate‐grown Penicillium citrinum catalyze the hydrolytic cleavage of the N‐glycosidic bonds of inosine, guanosine and adenosine optimally at pH 4, 0.1 M citrate buffer. The same extracts catalyze the hydrolytic deamination of cytidine at a maximum rate in 0.08 M Tris‐acetate buffer pH 6.5, 40°C and 50°C were the most suitable degrees for purine nucleoside hydrolysis and cytidine deamination, respectively. The incubation of the extracts at 60°C, in the absence of cytidine caused a loss in the deaminating activity, while freezing and thawing had no effect on both activities. The deaminating activity seems to be cytidine specific as neither cytosine, adenine, adenosine nor guanosine could be deaminated. Uridine competively inhibited this activity, while ammonia had no effect. The apparent Km value of this enzyme for cytidine was 1.57×10−3M and its Ki value for uridine was 7.8×10−3M. The apparent Km values of the N‐glycosidic bond cleaving enzyme for inosine, guanosine and adenosine were 13.3, 14.2 and 20×10−3 M, respectively.
The NAD‐dependent alcohol dehydrogenase (ADH) of hansenula polymorpha cbs 4732 – an electrophoretic study (II)
Authors: Steudel A. , Nitzsche C.
Published: December 2004

Using gradient polyacrylamide gel electrophoresis (gradient between 10–20%) we were able to show up to six clearly distinguishable ADH‐bands in Hansenula polymorpha CBS 4732. In contrast to commercial ADH from Saccharomyces cerevisiae the ADH‐forms of Hansenula polymorpha CBS 4732 have a much broader substrate specificity. Furthermore, the occurence of secondary alcohol dehydrogenases and of an aromatic alcohol dehydrogenase could be demonstrated.
Enzymatic production of indolepyruvate and some of its methyl and fluoro‐derivatives
Authors: Bode R. , Birnbaum D.
Published: December 2004

Using the tryptophan aminotransferase of the fodder yeast Candida maltosa the enzymatic production of indolepyruvate, and of analogues of indolepyruvate from tryptophan and methyl and fluoro‐derivatives of tryptophan was investigated. After the optimization of the reaction conditions such as pH, temperature, concentration of the cofactor and ratio between substrate and cosubstrate, a good yield of indolepyruvate (about 70%) and its derivatives (10–30%) was achieved. After isolation products were purified and crystallized.
Biotechnological aspects of antibody production in E. coli
Authors: Plückthun A.
Published: December 2004

The production of genetically engineered antibodies in Escherichia coli is now possible. The resulting fragments are completely functional and have antigen binding constants industinguishable from the natural antibody. This article summarizes the biochemical basis of this newly developed technology and the properties of the resulting fragments. It is likely that this technology will have an important role in antibody production for technical, medical and research uses. Screening of E. coli libraries may mount a challenge to traditional antibody production methods.
Calculating affinity constants of substrate mixtures in a chemostat
Authors: Bley Th. , Babel W.
Published: December 2004

An “oversimplified” method for calculating affinity constants in substrate mixtures is evaluated concerning its validity. It is shown that the real affinity to the mixture as determined by using the correct method is always higher, i.e., leads to a lower affinity constant, as compared to the wrong method frequently used.
Some studies on Nigerian palm wine with special reference to yeasts
Authors: Enwefa C. , Uwajeh R. , Oduh M.
Published: December 2004

The identification and enumeration of yeasts and the effect of chemical preservatives on the yeast load in Nigerian palm wine have been studied. Yeast found largely belong to the genus Saccharomyces. Other genera found were Candida, Endomycopsis, Hansenula, Kloeckera, Pichia, Saccharomycoides and Schizosaccharomyces. The viable yeast count ranged from 0.5 × 107 cfu/ml to 4.2 × 109 in both fresh Elaeis and Raphia spp. of palms. Yeasts in palm wine were least sensitive to sodium nitrate and most sensitive to sodium benzoate. The addition of these two chemical preservatives amongst others reduced the yeast count to 3.2 × 108 (in Raphia sp.), and 4.1 × 109 (in Elaeis sp.) with 0.025% sodium nitrate and 1.2 × 106 (in Raphia sp.) and 1.9 × 107 (in Elaeis sp.) with 0.1% sodium benzoate. The values of the yeast count in bottled and fresh palm wine were between 1.3 × 103 cfu/ml to 9.8 × 106 and 0.5 × 107 to 4.2 × 109, respectively. Maximum values of actual dry and theoretical yeast weights were 1.09 and 42 mg/ml, respectively.
Effect of formaldehyde on the level of cytochrome c in methylotrophic yeasts
Authors: Dercová K. , Augustín J. , Pekniková D.
Published: December 2004

The effect of formaldehyde on the cytochrome system of the methylotrophic yeasts Candida tropicalis, Candida boidinii, Candida methylica, Hansenula capsulata, Hansenula polymorpha, Pichia pastoris and nonmethylotrophic yeasts Saccharomyces cerevisiae was studied. In the investigated concentration range of 0.58 – 2.5 mol · 1−1, formaldehyde decreases the level of the reduced cytochrome c in the above‐mentioned microorganisms. The kinetics of the change in the reduced cytochrome c content has two phases: a phase of slow decrease and a phase of complete disappearance of the reduced cytochrome c in the cells. The duration of the first phase shortens with increasing concentrations of formaldehyde.
Effect of calcium carbonate on conversion of starch to ethanol by Schwanniomyces castellii
Authors: Mok K. L. , Duvnjak Z.
Published: December 2004

Conversion of starch to ethanol without its prior hydrolysis is of special interest in the treatment of the starch containing waste‐waters. In this work the effect of calcium carbonate on the growth and ethanol production from soluble starch by Schwanniomyces castellii NRC 2676 was studied. When the medium was supplemented with 0.1% calcium carbonate the biomass yield and the total starch consumption were increased by 20% and 22%, respectively, while the ethanol yield decreased for 28% in comparison with the control. The rate of biomass production, measured for the period of time between 0 and 24 h, was the highest in the medium with 0.06% calcium carbonate while the rates of ethanol production and starch consumption decreased with and increase in the concentration of that salt; the media with 0.5% and 0.7% calcium carbonate had 3.5 and 5.5 times lower ethanol production rates, and 2.3 and 3.8 times lower rates of starch consumption than the control medium which was not supplemented with calcium carbonate, respectively. The obtained results also showed that the percentage of starch consumed was higher in the media supplemented with calcium carbonate than in the control.

Empirical mathematical expressions are given for the relationship of the biomass and ethanol yields to the concentration of calcium carbonate in the medium.
Regulation of xylanase activity in cellulomonas sp. IIbc
Authors: Rodriguez H. , Alea F.
Published: December 2004

The regulation mechanism governing the xylanolytic activity in the strain Cellulomonas sp. IIbc was studied. High levels of activity were detected during the cultivation on cellulose as the only carbon source. No activity was produced with glucose, xylose or cellobiose cultures, but in the last one, the synthesis was de‐repressed when the sugar concentration dropped to 0.2%. The activity was not inhibited by glucose, cellobiose and xylose up to 1% concentration.

A basal constitutive synthesis was detected in nutrient broth cultures. At the same time, xylose and cellobiose acted as inducers of the xylanase activity.
Isolation and characterization of thermophilic bacteria from natural and artificial habitats
Authors: Zentgraf B. , Hedlich R. , Gwenner C. , Uyen N. V. , Thao N. N.
Published: December 2004

Several thermophilic Bacillus Strains were isolated from natural as well as artificial habitats. They grow optimally on a carbohydrate‐containing medium at a temperature of 65 to 68°C and a pH value of 6 to 7 under aerobic conditions. They utilize glucose, sucrose and sodium acetate as carbon and energy sources. They can be differentiated by acid formation and composition of intracellular fatty acid fraction as well as growth on xylose, lactose, starch, cellobiose, ribose and galactose.
Description of the delayed microbial growth by an extended logistic equation
Authors: Wolf K.‐H. , Venus J.
Published: December 2004

Logistic equations are suitable for describing microbial growth. By means of VERHULST'S logistic equation, the adaptation to sigmoid‐shaped curves of growth improves with a falling ratio Cxo/Cx, max < 0.2, if there is no lag‐phase. The known logistic equations do not take into account any lag‐phase behaviour, so that noticeable deviations in the model adaptation result in this range. Therefore, an extended logistic equation of rate is proposed by which any occuring lag‐time is expressed by a 1st‐order lag‐term. The corresponding time law allows a very good adaptation of curves of delayed growth behaviour, and changes into VERHULST'S logistic equation for a lag‐time tL = 0. Application is facilitated by instructions for the numerical determination.
Coexistence of competing microbial species in a chemostat where one population feeds on another
Authors: Lenbury Y. , Siengsanan M.
Published: December 2004

In this paper, we consider a model for a chemostat in which two microbial species compete for a single rate‐limiting nutrient, while one of the species feeds on another. Under certain simplifying hypotheses, such a chemostat can be described by a system of three nonlinear ordinary differential equations. A theoretical study is conducted to characterize the possible types of solutions. A limit cycle solution was obtained for some parametric values of the system indicating that coexistence of the two species is possible in a significant range of the operating parameters.
Thermophilic bacteria from spent liquor of pulp mills
Authors: Zentgraf B. , Gwenner C. , Hedlich R.
Published: December 2004

A thermophilic bacterial mixed culture was isolated from spent liquor of pulp mills, using a chemostat under aerobic conditions. It consists of two components belonging to genus Bacillus. The thermophilic Bacilli were cultivated aerobically and continuously at 67–70°C and pH 6.8–7, rising the percentage of spent liquor in stages. The dilution rate ranged from 0.2 to 0.33 h−1 during the experiments. The composition of the cell mass produced was analyzed.
Regulation of proteinase synthesis in Lactococcus lactis
Authors: Laan H. , Bolhuis H. , Poolman B. , Abee T. , Konings W. N.
Published: December 2004

The synthesis of extracellular serine proteinase of Lactococcus lactis was studied during the growth in a batch and a continuous culture on chemically defined media. In a batch culture the proteinase synthesis started during the exponential phase of growth and the highest proteinase concentrations were found at the end of the exponential and beginning of the stationary phase of growth. During the growth in a lactose‐limited chemostat with amino acids as the sole source of nitrogen, the specific rate of proteinase synthesis was maximal at a μof 0.23 h−1. At higher growth rates the proteinase productin declined. The proteinase synthesis was dependent on the amino acid sources in the medium. In batch cultures of L. lactis grown on a chemically defined medium with amino acids, the proteinase production was increased four‐fold compared to media containing casein or a tryptic digest of casein as the sole source of nitrogen. The inhibition of the rate of proteinase synthesis by casein and peptides was also observed during the growth in a chemostat. The addition of the dipeptide leucylproline (final concentration of 100 μM) to a lactose‐limited continuous culture during the steady state (D = 0.23 h−1) resulted in a transient inhibition of the rate of proteinase synthesis. This suggested that exogenously supplied peptides control the regulation of proteinase synthesis of L. lactis.
The recovery of the hepatitis B virus surface antigen (HBsAg) from a recombinant P. pastoris strain disruption and precipitation studies
Authors: Páez R. , Agraz A. , Herrera L.
Published: December 2004

Cell disruption studies for the extraction of HBsAg from a recombinant P. pastoris strain (r‐HBsAg) were done using a bead mill disintegrator. Three sequential passages (4 min retention time each) were enough to disrupt the cells and extract most of the r‐HBsAg and soluble proteins. An acid precipitation step was performed just after cell disruption to precipitate proteins together with the cell debris. Different precipitation pH values (2.5 to 6.0) were investigated. A pH value of 4.2 was selected as a compromise between recovery and improvement of specific activity. A 6 to 8‐fold enhancement of the specific activity was obtained, having a r‐HBsAg overall yield of about 80%. The influencing presence of a chaotropic salt (potassium thiocyanate) during the acid precipitation step was also studied.
Influence of carbon and nitrogen sources on the lipid accumulation and arachidonic acid production by Mortierella alpina
Authors: Stredanská S. , Šajbidor J.
Published: December 2004

Carbon and nitrogen influence the lipid accumulation and arachidonic acid production by Mortierella alpina CCF 185 cultivated at 28°C for 7 days on a rotary shaker. The fungus grown with glucose, starch or dextrin as the carbon source produced satisfactory amounts of lipid and arachidonic acid. The maximum arachidonic acid values were obtained on media with yeast extract or NaNO3 as the nitrogen source. The C/N ratio of 40:1 resulted in the highest yields of lipid and arachidonic acid with different amounts of NaNO3 concentration.
Optimization of sorbose production from sorbitol by Gluconobacter oxydans
Authors: Rosenberg M. , Švitel J. , Rosenbergová I. , Šturdík E.
Published: December 2004

The basic parameters were studied influencing the conversion of orbitol to sorbose by Gluconobacter oxydans(industrial strain from FARMAKON Co., Czechoslovakia). The most effective conversion in the stationary phase was reached at pH 5.0, no inhibitory effect of sorbitol in a concentration ranging from 20 to 200 g/l and a minimum inhibitory effect of the sorbose concentration up to 200 g/l were observed. According to the optimum conditions mentioned above the optimized course of the fed‐batch cultivation was proposed. The final concentration of sorbose of 410 g/l was reached after 36 hours.
The application of a new type of sintered glass carriers for the cultivation of anchorage‐dependent mammalian cells
Authors: Rzeski W. , Kandefer‐Szerszeń M. , Kaczor J. , Dawidowicz A. L. , Wozowicz A.
Published: December 2004

Cylinder‐shaped sintered glass carriers were successfully used for immobilizing and cultivating cells of murine line L929. The process has been performed in a fixed‐bed bioreactor (working volume of 150 ml) with perfusion and aeration of the medium (total volume of 3.5 l). The maximum cell density of 1.23 × 107cells/ml was achieved when the basal medium (MEM + 10% bovine serum) was enriched with glucose (up to 2 g/l) and L‐glutamine (up to 4 mM). The carriers have proved to be nontoxic, mechanically stable and reusable.