bluuebunny/crossref_metadata_2025 huggingface dataset:
A Procedure for gluconic acid synthesis with bacteria made continuous by means of an auxiliary substrate
Authors: Babel W. , Müller R. H.
Published: December 2004

A method is introduced which makes a continuous oxidation of glucose to glucose acid possible. This method is based on the auxiliary‐substrate concept and co‐metabolism, respectively. Micro‐organisms (e.g. Acinetobacter calcoaceticus), which cannot assimilate glucose, but merely oxidize it, are grown continuously on a heterotrophic substrate (e.g. acetate). While growing they simultaneously synthesize gluconic acid. The productivity of the gluconic acid synthesis with a given strain depends on the dilution rate and the mixing proportion.

Since growth and product synthesis are closely connected and growth yield is very much higher due to an auxiliary substrate effect in the presence of glucose than on the heterotrophic substrate alone, this method is suitable for SCP production as well. The productivity of gluconic acid production is controlled at a certain dilution rate by the mixing proportion of the growth substrate and glucose.
Wachstumskinetik von Aspergillus niger A.n./61 in einem festen Medium
Authors: Czajkowska D. , Ilnicka‐Olejniczak O.
Published: December 2004

Growth kinetics of Aspergillus niger strain A.n./61 on a solid medium containing beet pulp were examined.

Solid state fermentation was carried out in laboratory microfermenter (aerated packed columns). During the experiments the CO2 evolution, protein biosynthesis, as well as cellulose and sucrose utilization were determined.

It was found that CO2 evolution evidently increased in the logarithmic phase, together with the protein biosynthesis. Between 30–32 h of culture CO2 evolution and protein content in product were the greatest. Subsequently, CO2 evolution decreased.

During 28 h of culture, cellulose was slightly utilized, the strain using mainly sucrose. Intense utilization of cellulose was paralleled by a drop in CO2 evolution.
Antiphytovirale Aktivität von Rhamnolipid aus Pseudomonas aeruginosa
Authors: Haferburg D. , Hommel R. , Kleber H.‐P. , Kluge S. , Schuster G. , Zschiegner H.‐J.
Published: December 2004

A rhamnolipid released by Pseudomonas aeruginosa 196 Aa into the culture medium reduced the number of local lesions induced by tobacco mosaic virus on leaves of the hypersensitive host Nicotiana glutinosa L. by up to 90%. The content of potato virus X in the systemically infected host Nicotiana tabacum L. ‘Samsun’ is decreased in inoculated as well as in secondarily infected leaves by up to 50%. In a smaller degree red clover mottle virus is influenced in the systemic host Pisum sativumconvar.speciosum (Dierb.) Alef ‘Nadja’.
Cultivation of measles virus on bovine kidney cells: Comparative study on viral yield
Authors: Eghafona N. O. , Ezeokoli C. D. , Ahmad A. A. , Emejuaiwe S. O. , Odama L. E.
Published: December 2004

The present investigation sought the use of Bovine Kidney Cells (BKC) which is a readily available substrate for the cultivation and isolation of measles virus. Results showed that measles virus grew well on BKC, showing identical cytopathologic effect (CPE) of syncytial and giant cell formation also noted for Vero cells. However, the growth on Vero cells was faster indicating a better sensitivity to the measles virus than BKC. The virus replicated and produced CPE in both confluent monolayer and trypsin dispersed cultures. The ability of the virus to form CPE was faster in trypsin‐dispersed cells than confluent monolayers.

The viral yield in Vero‐ and BK‐cells were compared to assess any difference by analysis of variance. The F‐value of 0.824 with degree of freedom 1.34 showed no significant difference at any reasonable confidence interval.
Biochemical studies on the effect of various carbon sources on growth, nitrogen fixtion, and main cellular constituents of azotobacter vinelandii, strain IV grown under various cultivation conditions
Authors: Shawky B. T. , Ghali Y. , Ahmed F. A. , Kahil T.
Published: December 2004

The accessibility of different carbon compounds to Azotobacter vinelandii and the productivity of nitrogen fixation were studied under static and shaking culture conditions. The nature of the carbon source applied was found to affect the yield of bacterial mass and nitrogen metabolism of the tested organism. On the basis of the efficiency of dinitrogen fixation and the yield efficiency ratio it was obvious that (sucrose + mannitol) as a source of carbon is optimum for both growth and dinitrogen fixation by A. vinelandii grown under static and shaking culture conditions. Furthermore, it was found that the highest crude protein efficiency ratio (14.6) and total carbohydrates efficiency ratio (4.3) were obtained with (sucrose + mannitol) as energy source for this organism under shaking culture condition. The experimental organism is able to convert the soluble nitrogenus substances present in molasses into more complex protein as well as to utilize the molasses as a source of energy for the fixtion of atmospheric nitrogen. The tested organism was unable to utilize sodium salicylate as the sole source of carbon.
Wechselwirkungen zwischen seltenen Erdmetallen und Mikroorganismen
Authors: Bullmann M. , Iske U. , Glombitza F. , Dittrich B.
Published: December 2004

In recent years there have been a lot of works on the accumulation and removal of heavy metals from aqueous solutions and industrial waste waters by different kinds of microorganisms. A variety of microorganisms are known to be tolerant to mercury, copper, chromium, silver, cadmium etc., or to have a high accumulation capacity for these elements.

But nothing is known about the interactions between microorganisms and REE*‐ions in aqueous solutions.

The objectives of our experiments were to determine the ability of various microorganisms to accumulate REE and to determine what possible effects, in terms of growth, different REE‐ion concentrations may have on the bacteria cultures.

Experiments on the accumulation of La and Pr by a freeze dried bacteria mixed culture, carried out with model solutions, showed that the accumulation process is completed few minutes after contact. The uptake is independent on pH‐value and temperature and amounts up to 63 mg REE/g biomass in both cases.

A gram+ bacterium spec., isolated from an industrial waste water, accumulates large quantities of REE in dependence on the pre‐treatment of the cells, e.g. in the case of resting or freeze dried cells up to 100 mg/g biomass and in the case of heat treated cells up to 40 mg/l.
Gas chromatographic analysis of free fatty acids. Part 1. Principles and methodic variants
Authors: Pörschmann J. , Welsch T. , Pörschmann S.
Published: December 2004

Proceeding from a literature search the problems faced by the today's gas chromatographer concerned with analysis of free fatty acids are summarized. In terms of column technology self‐made OV‐1/FFAP mixed phase capillary columns are well suited for adequate tailing — free elution of these polar molecules. Whereas fatty acids having two and more carbon atoms can be analyzed in an underivatized state on acidic capillary columns, the involving of formic acid and dicarboxylic acids cells for deactivation procedures.
Einfluß ausgewählter Nährsalzionen auf die Wachstumskinetik des methanotrophen Bakteriums gb 25
Authors: Wendlandt K.‐D. , Jechorek M. , Brühl E. , Wittig H. , Osokina N. V. , Lalov V. V.
Published: December 2004

The influence of different concentrations of magnesium, potassium, phosphorus and copper on the growth kinetics of the methanotrophic bacterium GB 25 was investigated. Diverse inhibition models were used for the mathematical description of the results. On the basis of these model equations the optimal concentrations of the investigated ions were derived. Copper causes the greatest inhibition, on the contrary, potassium practically does not inhibit the growth of bacterium GB 25.
Hydrolysis of whey by kluyveromyces bulgaricus cells immobilized in stabilized alginate and in chitosan beads
Authors: Decleire M. , De Cat W. , Van Huynh N. , Motte J. C.
Published: December 2004

Kluyveromyces bulgaricus cells were immobilized in matrices resisting to complexing anions. Yeast entrapped in alginate stabilized by polyethylenimine and glutaraldehyde were unable to hydrolyse whey owing to the inactivation of β‐galactosidase by the stabilizing agents. Chitosan was resistant to whey medium but decreased the yeast hydrolyzing capacity by 15% with respect to alginate. The hydrolysis rate was found to be unchanged for 37 days at 21–25°C.
A kLa identification technique for a dynamic model of the coupled system: Air‐lift fermenter — oxygen probes
Authors: Gluszoz P. , Starzak M. , Michalski H.
Published: December 2004

The time delay of oxygen probe response to the signal from a fermenter makes identification of the volumetric oxygen transfer coefficient kLa by the dynamic method more complicated. A coupled model involving the transient‐state oxygen balance of the fermenter together with the dynamic model of the oxygen probe must be then formulated, solved and identified.

In this paper two simple models of air‐lift loop fermenters have been proposed and a coupled mathematical model of the fermenter – oxygen probe system has been developed. The identification procedure was used to estimate kLa values in the fermenter with internal circulation flow on the basis of experimental measurements. A comparison of evaluated and experimental indications of the probes placed at various heights of the column proves that the model presented gives a possibility of the first‐step approximation of kLa in loop fermenters.
Enzyme overproduction: Principle and application
Authors: Tripathi G.
Published: December 2004

The rapprochement between gene physiology and protein chemistry proffered a wishful manipulation or programming of biological blueprint which we now know as recombinant DNA technology. Its premises are very many and ends are manifold. Until rather recently, the recombinant DNA technique could conceive the idea of engineering enzyme molecules by cloning and selection of the gene in question for enzyme production. At least, in principle, the process is too simple but its underlying mechanism is rather much stringent. Various experimental paradigms have been brought to work for production of enzyme at will by introducing a given gene into a high yielding system of microorganisms. It facilitates overproduction of enzymes of interest which can be implicated in several important industrial, biomedical, and environmental processes at a large scale. Such approaches of enzymes made‐to‐application have already started asserting tremendously in doing their appropriate jobs at the level of molecular interactions. A rapid progress in this important and interesting area of biocatalytic manipulation will certainly achieve the goal of biocatalysis‐made‐to‐order by altering kinetic and thermodynamic components of enzyme molecules.
β‐Glucosidase production by Trichoderma reesei QM9414 on wheat straw. Location and some kinetic features
Authors: Acebal C. , Arche R. , Castillon M. P. , Estrada P. , Romero D.
Published: December 2004

In this paper we studied the conditions for the production of β‐glucosidase from T. reesei QM9414 in batch cultures using milled and sieved wheat straw as sole carbon source. High β‐glucosidase production in the presence of wheat straw, a more realistic substrate than commercial cellulose, was obtained.

The influence of particle size of wheat straw on β‐glucosidase production in cell‐free, cell and cell‐wall extracts was studied. The particle size of wheat straw notably influenced enzyme production in cell and extramycelial extracts but it was less important with respect to the cell wall bound enzyme.

β‐glucosidase production was studied along of the fermentation. The results suggest a close relation between β‐glucosidase from cell extract and extramycelial broth; geneticin levels of inhibition of β‐glucosidase biosynthesis in both fractions were similar, a fact that suggests a common origin for the enzyme.

Kinetic parameters for β‐glucosidase from cell free and cell extracts were Vmax = 0.28 μmol/min/mg, KM = 0.91 mM and Vmax = 0.095 μmol/min/mg, KM = 0.39 mM respectively. Kinetic parameters for β‐glucosidase from cell‐wall could not be calculated because experimental data did not fit the different monosubstrate equations.
Tween 80 and proteose peptone effect on cellulase production
Authors: Hung B. R. , Lara L. , Patrón M. A. , Clappes S. , Ugarova N. N. , Bechstedt W.
Published: December 2004

Tween 80 and proteose peptone effect on cellulase production with Trichoderma spec. was studied. Sugar cane pith was used in the medium as carbon source. Tween 80 increases cellulase production while proteose peptone has influence on enzyme adsorption. There is a combined effect on cellulase production between them.
Isolation and some properties of two extracellular β‐glucosidases from Trichosporon adeninovorans
Authors: Büttner R. , Bode R. , Scheidt A. , Birnbaum D.
Published: December 2004

The yeast Trichosporon adeninovorans secretes two multiple forms of β‐glucosidase at a high rate if grown in a medium containing cellobiose. Following mutagenesis a mutant strain resistant to 2‐deoxy‐D‐glucose was selected. This strain produced more β‐glucosidase activity and had acquired a strong resistance against repression by glucose. The β‐glucosidases were separated one from each other by chromatography on hydroxylapatite and by gel filtration. Both enzymes have similar properties. The optimal temperature for their activity was 60 to 63°C and the enzymes displayed highest activity at pH of 4.5. The molecular weight of β‐glucosidase I was found to be 570,000 and that for β‐glucosidase II was 525,000. The Km value for cellobiose was determined to be 4.1 mM for β‐glucosidase I and 3.0 mM for β‐glucosidase II.
L‐Lysine production by auxotrophic mutants of Arthrobacter globiformis
Authors: Samanta T. K. , Das Y. , Mondal S. , Chatterjee S. P.
Published: December 2004

By mutagenesis with N‐methyl N‐nitro‐N‐nitrosoguanidine, in two steps, a number of methionine plus threonine double auxotrophs have been isolated from a glutamate producing Arthrobacter globiformis, excreting L‐lysine in good amounts. For the three potent mutants tested the medium of WHITE was adjudged to be the best. Biotin, ammonium chloride and glucose was found to be optimum at 5 μg l−1, 40 mM and 4% level, respectively. With such optimal C and N source, the strain MT 35 yielded 28.0 g lysine l−1 of medium in flask culture.
Naturwissenschaftliche Aspekte eines diffusiven Strohaufschusses mit verdünnter Alkalilauge
Authors: Mietz M. , Berg F. , Philipp B. , Paul D. , Jacopian V.
Published: December 2004

Changes in chemical composition and morphology of wheat straw during a 5‐step treatment with delute aqueous sodium hydroxide of increasing (step 1 to 3) and then decreasing (step 4 and 5) NaOH concentration are described varying straw pretreatment, maximum NaOH concentration and total time of contact between straw and lye. These structural changes are correlated to increase in swelling, in‐vitro degradability by cellulase and digestibility as revealed by feeding tests with sheep. Results are discussed on the basis of the processes of swelling, delignification and pentosan extraction, and the technological advantages of this multi‐step treatment for enhancing the nutritional value of straw are discussed in comparison to a one‐step treatment with subsequent lye‐removal by pressing.
Zur biotechnologischen Relevanz von Regulationsvorgängen des mikrobiellen Sekundärstoffwechsels
Authors: Bormann E. J.
Published: December 2004

Although the regulation of microbial secondary metabolism belongs to the important objects of actual investigations the results and knowledges are used rather poorly in industrial fermentations. This situation arises from the discrepancy between the economically driven development of the know how as soon as possible contrary to the more slow progress of profound examination of the complicated network of secondary metabolism. Nevertheless some well known principles of metabolic regulation, e.g. catabolite repression or resistance against products or metabolites are considered in fermentation processes by means of suitable substrate application as well as improvement of high yield strains. Both aspects are discussed with respect to examples of fermentations of β‐lactams, polyketides and glycopeptides.
A reduced specific ethanol‐forming performance of yeast at high biomass concentrations as a result of a changed ethanol‐tolerance behaviour of the cells under condition of limitation I. A theoretical treatment
Authors: Richter K.
Published: December 2004

The loss of fermentative activity of yeast cells, observed in continuous fermentation experiments at increasing biomass concentration is explained by the assumption that the ethanol‐tolerance behaviour of the microorganisms changes if a growth‐stabilizing factor limitation is present. A mathematical specification of the relationships existing in this context is given and an improved steady‐state productivity model of ethanol production is derived.
A reduced specific ethanol‐forming performance of yeast at high biomass concentrations as a result of a changed ethanol‐tolerance behaviour of the cells under condition of limitation. II. Proving the effect in high‐flow rate fermentations with saccharomyces cerevisiae Sc 5
Authors: Richter K. , Becker U. , Meyer D.
Published: December 2004

In growth‐factor limited fermentations carried out in continuous high‐flow rate fermenters the relationship existing between the specific ethanol formation rate and the ethanol concentration was found to change its characteristics from a linear function into a nonlinear one at high biomass concentrations. The deviation from the linear inhibitory behaviour of the cells was the greater the more the biomass concentration increased.

A very good correspondence between the experimentally found productivities of ethanol formation and its adequate values obtained by calculation could be attained by using an improved steady‐state productivity model, in which the variability of the function v = f(P) had been considered.
Characterization of biotechnological processes and products using high‐performance liquid chromatography (HPLC) IV. SEC, HIC, and IEC separations of proteins
Authors: Gey. M. , Thiem M. , Gruel H.
Published: December 2004

Proteins are separated by means of size‐exclusion (SEC), hydrophobic‐interaction (HIC) and ion‐exchange chromatography (IEC). Analytical and semipreparative HPLC glass columns are the basis of the chromatographic analyses.

Using a short (100 × 3.8 mm i.d.) column packed with Si 200 Polyol standard of different molecular weights (ovalbumin, MW = 43 000; chymotrypsinogen A, MW = 25 000; ribonuclease, MW = 13 700 and contrycal, MW = 6512) could be distinguished.

Basic proteins (e.g., chymotrypsinogen A, cytochrome C) are separated on aluminium oxide (Li‐Chrosorb Alox T) by cation‐exchange chromatography. Correlations between the retention times of proteins and their isoelectric points or the buffer concentration of the mobile phase are investigated.

Furthermore, two examples of liquid chromatographic purification procedures for enzymes of biotechnological interest are demonstrated. One enzyme extract (thermostable protease) is separated by hydrophobic‐interaction chromatography, another one (β‐galactosidase from a thermophilic microorganism) is purified on a weakly basic anion‐exchange resin (pore size: 130 nm) based on a styrene‐divinylbenzene copolymer.
Flow cytometric determination of yeast sterol content
Authors: Müller S. , Schmidt A.
Published: December 2004

A method for the flow cytometric determination of the unesterfied 3β‐hydroxysterol content in yeast populations by the fluorescence shifted macrolide nystatin in presented. Preliminary investigations of changing sterol content in aerobic and anaerobic batch cultivation revealed the technological usefullness of this information.
Macromixing characteristics of gas‐liquid jet loop reactors
Authors: Warnecke H.‐J.
Published: December 2004

Measurements of liquid macromixing characteristics are reported for a half industrial scaled jet loop reactor operating with air‐water mixtures. Based on a model of loop reactors with sections of different mixing behavior the single circulation dispersion coefficient can be split into its components caused by the riser and the downcomer. The dispersion coefficient of the riser is about 100 times greater than that of the downcomer. The addition of gas involves greater dispersions coefficients. The comparison of the mixing times of the JLR with those of stirred vessels leads to the conclusion that the JLR is equivalent or even superior to stirred vessels.
Lysine production by auxotrophic‐regulatory mutants of corynebacterium glutamicum
Authors: Plachý J.
Published: December 2004

A mutant of Corynebacterium glutamicum dependent on homoserine and resistant both to S‐(2‐aminoethyl)‐L‐cysteine and lysine hydroxamate, cultivated under submerged conditions for 4 days in a medium containing sucrose, corn‐steep and pea nut meał hydrolyzate, accumulated 33.5 g/l lysine.
Infrared and antimicrobial studies on different lignins
Authors: Nada A. M. A. , El‐Diwany A. I. , Elshafei A. M.
Published: December 2004

The aim of this work is to study the IR spectra of the different lignins precipitated from the produced liquor of different pulping conditions of bagasse and cotton stalks, also to study their antimicrobial activities towards some bacteria and fungi.
Mathematical modelling of immobilized living yeast cell reactor for sugar bioconversion to ethanol
Authors: Jinescu G. , Lavric V. , Brǎgǎrea St. , Popescu M.
Published: December 2004

In the present work, a mathematical model was developed regarding the immobilized living yeast cell reactor for sugar bioconversion to ethanol. The model, composed of a system of ordinary differential equations (ODEs) enables the computation of the paramters involved in the steady state reactor behaviour. Comparing the values computed through the integration of this mathematical model with the experimental data, it has been shown its capacity to describe sufficiently accurate the steady state behaviour of the continuous fixed film bioconversion reactor.
Neuere Erkenntnisse zur Regulation des Sekundärstoffwechsels von Streptomyceten
Authors: Gräfe U.
Published: December 2004

A survey is given summarizing recent insights into the causes of the genetic segregation of antibiotic‐producingStreptomycesstrains (plasmids, transposons, reiterated gene sequences, direct and inverted repeats). Referring to the classical regulatory models of prokaryotic operons, similar regulatory principles were shown to be involved in the secondary metabolism (pab‐gene ofS. griseus, brp‐gene ofS. hygroscopicus, afs B‐gene and A‐factor ofS. griseus) and the known features of its control by catabolites as well. The heterogeneity of the transcriptional system (multiple promotors and holoenzymes of the RNA polymerase) is shown to constitute an essential element of the secondary metabolism accomplishing its integration into cellular cytodifferentiation.
Optimization of some culture parameters and properties of β‐glucosidase and β‐xylosidase from Penicillium funiculosum NRRL – 13033
Authors: El‐Diwany A. I. , Hamdy A. H. A. , Farid M. A.
Published: December 2004

Penicillium funiculosum NRRL 13033 produced β‐glucosidase and β‐xylosidase activities when grown on wheat straw. The addition of some inducers (individually or in combination) to the fermentation medium were tested for the production of both enzymes. The relation of mycelial bound enzyme to cell free enzyme was studied during incubation period of fermentation. The optimum activity of β‐glucosidase and β‐xylosidase were found to be in the pH 4.5 using phosphate‐citrate buffer at 50°C for 60 min and at 55°C for 40 min respectively. β‐Glucosidase lost about 40% of its original activity by heating to 65°C for 60 min, while, β‐xylosidase activity was found to be nearly stable with the same treatment. Both enzyme activities were greatly inhibited when 1.0% (w/v) of xylose and glucose were added to the assay mixture.
Isolation and purification of isoenzymes of cellobiohydrolase I and II of trichoderma reesei using LPLC methods
Authors: Witte K. , Heitz H.‐J. , Wartenberg A.
Published: December 2004

Five cellulases were fractionated from a commercial cellulase preparation (CelluclastTM) Two isoenzymes of cellobiohydrolase I (CBHI)(pI = 4.1) could be proved to be real exo‐glucanases due to their activity towards MU (=methylumbelliferyl)‐lactoside being inhibited by cellobiose (5 mM) and due to production of cellobiose from carboxymethylcellulose (CMC) as the sole final product.Two isoenzymes of CBHII (pI=6.15, 6.0) were shown to act as endo‐glucanases because they produced glucose, cellobiose and cellotetraose from CMC and because they were not inhibited by cellobiose when decomposing MU‐lactoside. Results confirm recent reports in the literature classifying CBHI and CBHII as exo‐type and endo‐type cellulases, respectively. Both the CBHI and the CBHII isoenzymes were shown to be active towards CMC and amorphous cellulose.CBHI and CBHII reactions could be differentiated from one another by the velocities of decomposition of CMC: CBHI acts slowly and linearly whereas CBHII acts strongly and exponentially.The fifth of the purified enzymes must be classed as a conventional endoglucanase which exhibits activity towards CMC but fails to be active towards MU‐lactoside and amorphous cellulose.
Effects of temperature on the growth of the thermotolerant methylotrophic bacillus sp. NCIB 12522 in chemostat culture
Authors: Al‐Awadhi N. , Hamer G. , Egli Th.
Published: December 2004

The effects of temperature on chemostat cultures of a thermotolerant, methylotrophic Bacillus ap. are reported. In spite of the relative fastidiousness of this bacterium, overall response to a range of growth temperatures is predictable. However, anomalous results with respect to biomass yield coefficients are evident, suggesting complex and extensive endogenous and exogenous activities under some growth conditions.
Significance of composition and structure of the enterobacterial outer membrane to the transport of desired and undesired substances and its inhibition
Authors: Seltmann G.
Published: December 2004

The enterobacterial outer membrane forms a bilayer. Its outer monolyer consists of lipopolysaccharides and proteins, its inner monolayer of phospholipids and proteins. It thus represents an efficient penetration barrier against hydrophobic and anionic compounds (such as detergents or hydrophobic antibiotics) and against higher molecular substances (such as proteolytic, lipolytic, and murolylic enzymes).

Some of the proteins (“porins”) form channels through the outer membrane through which neutral and cationic hydrophylic compounds up to a molecular weight of about 800 can pass. Besides the porins additional transport systems have been described. They play an important part in providing the bacteria with substances necessary for their growth, i.e., phosphate, iron ions, and others.

Organic polycations are able to generate more or less severe disorganizations in the outer membrane through which they can pass the bilayer (“self‐promoted pathway”). Some of these polycations represent efficient antibiotics (polymyxin B, nourseothricin). Bacteria are able to protect themselves against the harmful action of these substances by changing the composition of the outer membrane.
Identification of D‐galactose‐(1 → 7)‐3‐deoxy‐d‐manno‐2‐octulo‐pyranosonate as component of the inner core region of escherichia coli EH 100 lipopolysaccharide
Authors: Holst O. , Röhrscheidt‐Andrzejewski E. , Cordes H.‐P. , Brade H.
Published: December 2004

The dissaccharide D‐galactosyl‐3‐deoxy‐D‐manno‐2‐octulosonic acid (Gal‐KDO) from lipopolysaccharides (LPS) of the inner core region of the rough mutant EH100 of E. coli 0100 was isolated after mild acid hydrolysis of LPS by means of dialysis, ion‐exchange chromatography, gelfiltration and high‐voltage paper electrophresis. By chemical analysis galactose and KDO were identified in a molar ratio of approximately 1 : 1. 13C‐NMR and 1H‐NMR studies, methylation analysis and GLC of the acetylated R.( – )‐2‐butyl‐galactoside identified the structure magnified image.
Brauchbarkeit der ATP‐ und Dehydrogenaseaktivitätsmessungen, und der Sauerstoffverbrauchsgeschwindigkeit zur Intensitätsbeurteilung des Belebtschlammverfahrens
Authors: Miksch K.
Published: December 2004

Some measurements of the metabolic activity of microorganisms in a standard activated sludge system have been made. The investigations have shown that the measurements of the respiratory activity of microorganisms are a convenient and reliable method for determining the metabolic activity of microorganisms. The values of respiratory activity have shown a high correlation with the rate of substrate removal in a continuous activated sludge process. Hydrogenase activity has shown moderate correlation with the rate of substrate removal.

The ATP values did not correlate with any of the methods of measuring the metabolic activity of microorganisms and the quantity of the dry organic mass of activated sludge. Howeever, the highest correlation between the particular parameters of the activated sludge process was obtained after assuming that the ATP total corresponds to the quantity of the active biomass which fact points at the correctness of such an assumption.
Purification and immobilization of the inducible form of extracellular laccase of the fungus trametes versicolor
Authors: Rogalski J. , Dawidowicz A. L. , Leonowicz A.
Published: December 2004

The inducible form of extracellular laccase (EC 1.10.3.2) produced by Trametes versicolor culture in a 10 1 glass fermenter was isolated and purified by ion‐exchange chromatography on the DEAE‐Sephadex A‐50 column and by affinity chromatography on a syringyl‐CPG column. The enzyme was further immobilized on functionalized porous glass. The paper also discusses some properties of immobilized and free enzyme, respectively.
Cassava whey treatment with aspergillus niger
Authors: Ikenebomeh M. J. , Chikwendu A. E.
Published: December 2004

Treatment of Cassava whey with Aspergillus niger was investigated. Heated cassava whey supplemented with ammonium sulphate (NH4)2SO4 and potassium di‐hydrogen phosphate (KH2PO4) called supplemented cassava whey (SUCW); heated but unsupplemented cassava whey (USCW); and cassava whey as is, unsupplemented and unheated (UHCW), were used as waste sources and growth media. Total reducing sugars, starch, total carbohydrate, specific gravity, hydrocyanic acid (HCN), biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of A. niger inoculated samples and uninoculated set were monitored on a time course basis for 5 days using standard methods. Percentage reductions in the BOD and COD were 69.7 and 54.5 respectively for SUCW samples; 42.4 and 29.5 for USCW samples while values for UHCW were 9.0 and 4.5. The reductions in reducing sugars, starch, total carbohydrate, specific gravity and cyanide content in descending order were SUCW; USCW and UHCW. The heated and A. niger inoculated cassava whey samples were better purified than both the unheated but inoculated and unheated and uninoculated cassava whey samples.
Purification of human tissue‐type plasminogen activator (t‐PA) from melanoma cell culture medium by different affinity chromatographic methods
Authors: Fischer B. E. , Zacharias U. , Wernicke D. , Will H.
Published: December 2004

Supernatants of a melanoma cell line were chromatographed on five affinity supports to evaluate and compare purification protocols for isolation of tissue‐type plasminogen activator (t‐Pa).

t‐PA was effectively adsorbed quantitatively from cell culture supernatants by lysine‐Sepharose, concanavalin A‐Sepharose, zinc‐chelate‐Sepharose and monoclonal antibody‐Sepharose. The major part of t‐PA was effectively adsorbed also by heparin‐Sepharose. About 20 per cent of t‐PA activity present in the culture medium however was not bound to the latter support, which indicates a heterogeneity of melanoma t‐PA. The heterogeneity is not due to carbohydrate variants I and II since both vriants were adsorbed and eluted from all the affinity supports investigated.

Highly enriched t‐PA preparations were obtained by sequential chromatography on two supports. t‐PA isolated by monoclonal antibody affinity chromatography and subsequently purified by gel filtration was of highest purity. Other useful combinations were chromatography on concanavalin A‐Sepharose or lysine‐Sepharose followed by chromatography on heparin‐Sepharose, or zinc‐chelate‐Sepharose followed by chromatography on lysine‐Sepharose.
Model simulation of an efficient periodic control strategy for continuous fermentation processses
Authors: Möckel B. , Bley Th. , Böhme B.
Published: December 2004

Simulation experiments of a periodic control regime for continuous fermentation processes are described. They are carried out with a state‐structure model on the basis of a system of delay‐differential equations. The perception of a fermentation system as an ecosystem leads to new and informative results which are to be applied to the development of efficient periodic control strategies.
Classification of yeasts by means of the BD1 data bank
Authors: Brüggemann L. , Geyer W. , Serfas O. , Standfuss G. , Fiedler E. , Sommer S. , Flemming I. , Nagel B.
Published: December 2004

Computerized procedures for the classification and discrimination of yeasts are presented which base on feature data files and classification techniques involved in a data bank project (BD1). Microbiological (physiological and morphological) and analytical feature data classes (fatty acid patterns from gas chromatography, fourier coefficeints from FTIR spectra, fluorescence patterns) were used to show the possibilities of yeast classification, carried out by means of these features and statistical or non‐statistical methods. Results obtained by a suitable combination of these methods are presented.
Some achievements of biotechnology application in anticancer drug research in China
Authors: Xu B. , Liu J.
Published: December 2004

Cancer is the bitter enemy to human health. Searching for effective antitumor drugs is one of the most important medical research problems. In China during the last 30 years a great deal of chemical compounds as well as natural products including medicinal herbs have been screened and investigated [1]. Some of them have been recommended for clinical trials and put into production. In our laboratory anticancer agents such as actiomycin K, antimony complexones, nitrocaphane, homoharringtonine (HHRT), hydroxycamptothecin (HCPT), lycobetaine (LBT) and oxalysine (OXL) were studied in detail. In recent years we payed much attention to elucidation of mechanism of drug action using genetic engineering technique. In this paper some new results will be reviewed.
The application of linear irreversible thermodynamics to biological growth
Authors: Baumann F.
Published: December 2004

We measured the rate of cell biomass growth, the consumption of organic substrate, and the heat developed during growth. The relationship between thermodynamic efficiency and the rate of microbial growth was considered.
Optimization of solid state fermentation of sugar cane by aspergillus niger considering particles size effect
Authors: Echevarria J. , Leon J. A. Rodriguez , Espinosa M. E. , Delgado G.
Published: December 2004

The protein enrichment of sugar cane by solid state fermentation employing Aspergillus niger was optimized in a packed bed column using a two Factor Central Composit Design α = 2, considering as independent factors the particles diameter corresponding to different times of grinding for a sample and the air flow rate. It was significative for the air flow rate (optimum 4.34 VKgM) and the particle diameter (optimum 0.136 cm).

The average particle size distribution, shape factor, specific surface, volume‐surface mean diameter, number of particles, real and apparent density and hollowness for the different times of grinding were determined, in order to characterize the samples.
D‐Glucose Isomerization using an Immobilized Glucose Isomerase preparation from Streptomyces Thermovulgaris Strain 127
Authors: Vlaev S. D. , Elenkov D. , Tsenova M. , Stoychev M. , Djejeva G.
Published: December 2004

The kinetics of D‐glucose isomerization to D‐fructose by an original whole‐cell immobilized biocatalyst preparation based on Streptomyces thermovulgaris (strain 127) have been studied under various process conditions, substrate concentration, particle size. Two versions of different activity were applied. For the biocatalyst of moderate activity the kinetic constants in the MICHAELIS ‐MENTEN equation for reversible reaction were determined. Effectiveness factors for both preparations were calculated and compared with other reported data.
Possibilities of increasing the expression of cloned foreign genes in e. coli
Authors: Venetianer P.
Published: December 2004

Possibilities of increasing the expression of cloned foreign genes in E. coli: Methods to increase the gene copy‐number; Methods to increase and control the rate of transcription; Methods to increase the rate of translation; Methods to increase the stability of the synthetised protein or peptide; Methods to increase the stability of recombinant plasmids. Each of these possibilities will be illustrated by examples from our laboratory.
Active protein and substrate flow effects in a tubular immobilized invertase reactor
Authors: Onyezili F. N.
Published: December 2004

Investigations of invertase (EC 3.2.1.26) immobilized inside modified nylon tubes showed that between 4% and 20% (w/w) of the protein exposed to binding sites on the tube was immobilized. An enhanced activity consistent with enzyme purification during immobilization was also evident, suggesting that, in scaled‐up commercial applications, nylon tube invertase would be a more economical converter of sucrose than the free enzyme. The quantity and specific activity of the immobilized protein were not stochiometrical with the amount used in the coupling solution and, in the system studied, a concentration of 2 mg ml−1 was optimal.

Km and Vmax values confirmed higher rates of immobilized invertase catalysis when the rates of substrate flow through the reactor were higher. Higher rates of substrate flow imply a shortened residence time in the reactor and would lower the fractional conversion per pass of the substrate, reducing the efficiency of the reactor in flow‐through situations. Thus, these higher catalysis rates, attributable at the higher flow rates to a reduction of the diffusion barrier between enzyme and substrate, would not translate into improved economy in the commercial flow‐through processes at which the reactor is aimed.
High performance fermentation process using methanol utilizing bacteria
Authors: Pöhland H.‐D. , Sawistowsky J. , Jechorek M. , Schulze E.
Published: December 2004

In a process running more than five months it was proved that a nonsterile processing is possible at a stable microbial composition as well as stable performance parameters like productivity, growth yield, and product quality.

For the stable processing it is important that methanol and dissolved oxygen concentration must not simultaneously exceed the threshold values (methanol> 1 g/1; dissolved oxygen > 0,5 mg/1).

The postulated transfer rate obstructs at higher biomass concentrations did not occur in the examined ranges up to 80 kg biomass/1. Consequently, the growth rate did not depend on high biomass concentrations in this range.
Synergistic cooperation of cellulases of trichoderma reesei as distinguished by a new filter‐paper destruction assay
Authors: Kolev D. , Witte K. , Wartenberg A.
Published: December 2004

WHATMAN 1 CHR filter paper manufactured from macerated cotton fibers was shown to be a soft substrate when broken down by purified cellulases of Trichoderma reesei (CELLUCLAST). Destruction of filter‐paper disks was induced by CBH I/1, CBH I/2, CBH II/1, CBH II/2, and EG I in a macroscopic assay. Attack on disks by mixtures of these cellulases (CBH I/1 or CBH I/2 mixed with CBH II/1, CBH II/2, or with EGJ) were followed by synergistically enhanced destructions.

SCHLEICHER &SCHUELL filter paper No 595 was shown to be a harder substrate of enzymatical decomposition when induced by cellulases of CELLUCLAST. None of the cellulases could induce macroscopic destruction of filter‐paper disks when acting in isolation. However, mixtures of isolated exo and endo‐glucanases (CBH I/1 or CBH I/2 mixed with CBH II/1, CBH II/2, or EG I) caused powerful destruction of filter‐paper disks.

SCHLEICHER &SCHUELL filter paper No 595 incubated first with an endo‐glucanase (CBH II/1, CBH II/2, EG I) and treated in a secondary incubation with an exo‐glucanase (CBH I/1, CBH I/2) were destroyed to a greater extent than with incubations executed in the reverse order. Results confirm the endo exo concept of explaining cellulose decomposition.

The filter‐paper destruction assay was performed with filter‐paper disks prepared with an office punch. Disks were incubated in 1 ml EPPENDORF reaction tubes filled up beforehand with 0.4 or 0.5 ml of enzyme solution. The degree of synergism of cellulases resulted from the assay in the range of 300 to 1 300 p.c.
Contributions to the biotechnological production of sweeteners from stevia rebaudiana bertoni. I. A method for the serial analysis of diterpene glycosides by HPLC
Authors: Striedner J. , Czygan F.‐C , Braunegg G.
Published: December 2004

An existing HPLC‐method for the analysis of stevioside from Stevia rebaudiana plants was adapted to analyse plant cell culture material. A new extraction method with methanol was developed. Exhaustive extraction of many samples (10 with our apparatus) can be done simultaneously. The quality of extraction is better than soxhlet extraction because the cold methanol was used. Samples with low stevioside content can be prepared with minimal loss. Substances which interfere with stevioside in HPLC analysis using UV detection are common in plant cell culture samples and hence need a special technique of elimination. This was accomplished by TLC‐purification of the samples.
Characterization of biotechnological processes and products using high‐performance liquid chromatography (H P L C). VII. Determination of organic compounds in sulphite liquor
Authors: Gey M. , Rietzschel A. , Nattermüller W.
Published: December 2004

Carbohydrates, acetic acid, furfural, 5‐hydroxymethylfurfural (HMF) were analyzed in sulphite liquor using HPLC with refractive index detection.

Pentoses (xylose, arabinose) and hexoses (glucose, galactose, mannose) were separated on an Aminex HPX‐87P column as wel as by means of a self‐made glass cartridge packed with a piperazine impregnated silica gel. Before injecting into the HPLC apparatus the sulphite liquors were purified using a presep column packed with a cation‐exchange resin. The sugar quantification between the two different separation systems was satisfactory.

Using an Aminex HPX‐87P column and an UV monitor set at 283 nm connected in parallel with the RI detector also furfural and HMF could be analyzed in sulphite liquor.

Furthermore, an Aminex HPX‐87H column and an UV detector set at 210 nm were most suitable to quantify ethanol.

These modified and optimized liquid chromatographic separation systems are the basis for further investigations of the utilization of hexoses as well as pentoses in sulphite liquors by means of suitable microorganisms.
In situ detection and localization of bioluminescent streptomyces coelicolor in liquid and soil by photon imaging
Authors: Mahro B. , Schleinkofer. L , Kasche V.
Published: December 2004

The successful cloning of the bioluminescence genes from marine bacteria offers the chance to use the bioluminescence phenotype as a marker for environmental monitoring purposes. This work describes a video camera based technique which allows both the sensitive detection and determination of the spatial distribution of luminescent Streptomyces coelicolor pellets and filaments within liquid and soil samples.
Production of microbial exopolymers for application as flocculants in waste water treatment
Authors: Pörschmann S. , Pätz R. , Zirkler W.
Published: December 2004

Organic synthetic polymers such as polyacrylamide derivates, polythylenimine, Na polyacrylates etc. have received much attention as flocculating substances used in waste water treatment. There is an urgent need for the production of effective flocculants to replace mechanical separation methods or, at least, to optimize them. Biological safety and decomposition are essential pre‐requisits for utilizing flocculants produced by microbial processes (e.g. discontinuous and continuous cultivation of bacteria or yeasts).

The extracted polymers consisting of proteins, lipids, nucleic acids and polysaccharides are capable of being degraded easily by microbiological reactions because they are natural compounds. The induction phase of excreting cellularic biopolymers is the crucial stage. In the special literature, lowpO2levels associated with a high concentration of the carbon source, limitation of N, P and trace elements have been recommended for the induction of excreting exopolymers.

In order to ensure sufficiant induction, we preferred a special procedure, the main characteristic of it being changed between limitation and excessive supply of components essential for the growth of microorganisms.

The quality control of exopolysaccharides for flocculation was determined by turbidimetric methods and sedimentation tests with caoline as a standard substance. For the initial investigationsAcetobacter methanolicusandmethylobacterium rhodesianumwere used.
Use of the fluidization technique in bioengineering
Authors: Behns W. , Ebenau B. , Haida H. , Künne H.‐J. , Lakowitz R.
Published: December 2004

Some special features of the fluidization technique, such as very good mixing behaviour, small‐scale abrasive and thermical stress, permit an advantageous utilization in bioengineering. The use of the fluidization technique for fermentation, immobilization and working up and conditioning is investigated. Existing results with regard to using gas‐fluidized beds in bioengineering are promising and have been investigated further.
Dynamic process control versus steady‐;state fermentation
Authors: Zentgraf B. , Rogge G. , Bley T.
Published: December 2004

Process control strategies, e.g. the steady‐;state fermation, which do not consider the cell‐;state distribution of cell populations, cause a decrease of yield coefficient connected to an increase of heat‐;production coefficient.

Contrary to this, the dynamic process control adapts the carbon‐;substrate supply to the different repetitive cell‐;population states during fermentation. In order to recognize the different states, the cell population is synchronized. The optimum period ofchanging carbon‐;substrate supply was found to be dependent on the cell‐;doubling time. Dynamic process control causes a higher yield coefficient as well as a lower heat‐;production coefficient compared to the steady‐;state fermentation.
Effect of ethanol, temperature and pH on the stability of killer yeast strains
Authors: Michalčáková S. , Repová Ľ.
Published: December 2004

The effects of temperature, pH and ethanol on the stability of killer wine yeasts were studied. Laboratory and collection strains as well as the strains prepared by the protoplast‐fusion technique were used and a decline of killing activity was observed in the complete medium and in grape juice. The relationship between the loss of killer properties in fusant strains and the stability of the original donor strain was established. The negative effect of the ethanol addition on the killer character of the strains used and the possibilities of its stabilization are discussed.