bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractFive 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractSome 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

AbstractThe 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

AbstractTreatment 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

AbstractSupernatants 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

AbstractSimulation 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

AbstractComputerized 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

AbstractCancer 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.
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

AbstractThe 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

AbstractThe 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

AbstractPossibilities 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

AbstractInvestigations 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

AbstractIn 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

AbstractWHATMAN 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

AbstractAn 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

AbstractCarbohydrates, 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

AbstractThe 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

AbstractOrganic 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

AbstractSome 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

AbstractProcess 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

AbstractThe 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.