bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of nutrients on the toxicity of pesticides carbofuran and hexachlorocyclohexane to blue‐green alga Nostoc muscorum
Authors: Kar S. , Singh P. K. 
Published: July 2010

AbstractThe effects of various levels of nutrients like potassium phosphate (dibasic), calcium nitrate, and calcium chloride individually and in combinations were studied on the toxicity of the commonly used pesticides carbofuran and hexachlorocyclohexane (HCH) in growth medium to the N2‐fixing blue‐green alga Nostoc muscorum. It was observed that all these chemicals had some effects on toxicity. The toxicity of both carbofuran and HCH was reduced to some extent in the presence of higher concentrations of the nutrients when compared to normal levels of the chemicals in the medium. The higher doses of nutrients in combinations antagonized the effect of individual treatment and enhanced the toxicity of pesticides.
Alcohol‐induced switching over of metabolic flux in Streptomyces noursei JA0 3890b
Authors: Gräfe U. , Schade W. , Bocker H. , Thrum H. 
Published: July 2010

AbstractShort‐chain alcohols, benzyl alcohol and Tween 20 were found capable of switching over the metabolic flux in Streptomyces noursei JA 3890b from the preference of oxidative deamination of alanine towards the reinforced acquisition of NH. These changes were correlated to the decrease of the ratio of saturated to olefinic fatty acids in the mycelium, suggesting that alcohols and other polar lipophilic compounds can interfere with the biosynthesis and the function of the cytoplasmic membrane in Streptomyces.
Agglutinationsverhalten von Hefen mit Lektinen
Authors: Meinhold I. , Gabert A. , Wünsche L. , Roth P. 
Published: July 2010

AbstractEs wurden ca. 160 Hefestämme aus verschiedenen Familien, Gattungen und Arten der Ascomyceten. Deuteromyceten und Basidiomyceten bei konstanter Zellzahl und Lektinkonzentration auf ihre Agglutinierbarkeit durch Lektine getestet (Concanavalin A, Lens culinaris‐Hämagglutinin, Weizenkeimlingsagglutinin, Dolichos biflorus‐Agglutinin, Erdnuß‐Hämagglutinin, Ricinus communis‐Hämagglutinin). Dabei ergaben sich gruppenspezifische Agglutinationsmuster. Ein Stamm der Art Rhodosporidium toruloides kann durch Weizenkeimlingsagglutinin zur Agglutination gebracht werden.Einige Hefestämme der Gattung Rhodotorula und Rhodosporidium lassen sich durch die untersuchten Lektine nicht agglutinieren. Sie besitzen offenbar gegenüber den anderen geprüften Hefen deutlich abweichende Zellwandstrukturen.
Unterschiedliche Empfindlichkeit der Phagen T3, T7, T4 und Lambda gegen Bleomycin und Phleomycin
Authors: Scholz D. , Meissner Ch. , Rosenthal H. A. 
Published: July 2010

AbstractIn contrast to phage lambda the phages T3, T7 and T4 are not inhibited by as much as 150 μg bleomycin/ml, while the chemically related antibiotic phleomycin increasingly inhibits the propagation of the phages in the order T4‐T3‐lambda. 20 μg phleomycin/ml inhibit T3 by 95%.The resistance against bleomycin is surprising, because 10 μg BM/ml block completely the colony‐forming capacity of the host bacterium. The drug resistance of the phage growth correlates with the weak decrease of phage DNA synthesis, while the host cell DNA synthesis ceases rapidly. In accordance with these data is thein vivoinhibition ofEscherichia colicells and thein vitrodegradation of their DNA. However, a contradiction exists between thein vivoresistance of T3 and T4 and thein vitrosusceptibility of their DNA against nucleolytical fragmentation by bleomycin.The mechanism of the insensitivity of T3, T7 and T4 against bleomycin is unknown.
Purification and properties of a fibrinolytic enzyme from Bacillus subtilis
Authors: Fayek K. I. , El‐Sayed Sanaa T. 
Published: July 2010

AbstractA fibrinolytic enzyme obtained from B. subtilis was purified, using DEAE‐cellulose column chromatography, and gel filtration on Sephadex G‐100. The preparation was homogeneous as tested by gel filtration on Sephadex G‐200, and disc electrophoresis.The molecular weight of this enzyme was 29.400 estimated by gel filtration on Sephadex G‐100. The optimum pH for enzyme activity was 7.2. Copper ions significantly increased enzyme activity, while Zn++ and Mn++ caused marked inhibition.
Regulation of NAD+‐ and NADP+‐linked isocitrate dehydrogenase in the obligate methylotrophic bacterium Pseudomonas W6
Authors: Hofmann K. H. , Babel W. 
Published: July 2010

AbstractCell‐free extracts of the obligate methanol‐utilizing bacterium Pseudomonas W6 catalyze the oxydation of isocitrate to α‐ketoglutarate in the presence of NAD+ and NADP+. After electro‐focusing of the crude extract of Pseudomonas W6 actually two distinct bands each of NAD+‐linked isocitrate dehydrogenase (NAD+‐IDH) and of NADP+‐linked isocitrate dehydrogenase (NADP+‐IDH) could be observed. The NAD+‐IDH was completely separated from the NADP+‐IDH by employing DEAE ion exchange chromatography and further purified by affinity chromatography using Cibacron blue F 3G‐A.The NAD+‐IDH was inhibited by a high energy charge, whereas the NADP+‐IDH was found to be independent of energy charge. Consequently the NAD+‐IDH showed the control behaviour of an enzyme of an energy‐generating sequence which, however, equally fulfils a catabolic and an anabolic function. With respect to the inhibition by reduced pyridine nucleotides and α‐ketoglutarate differences between NAD+‐IDH and NADP+‐IDH were also found. Only the NADP+‐linked enzyme exhibited a feedback inhibition by its reaction products α‐ketoglutarate and NADPH. This control behaviour gives evidence for the biosynthetic function of the NADP+‐IDH. These results confer an amphibolic character to the sequence from citrate to α‐ketoglutarate in the incomplete citric‐acid cycle of Pseudomonas W6.
Control by phospho‐adenosinediphospho‐ribose of NADP‐dependent isocitrate dehydrogenase and 6‐phosphogluconate dehydrogenase in Streptomyces griseus
Authors: Gräfe U. , Bormann E. J. , Truckenbrodt G. 
Published: July 2010

AbstractThe metabolic function of NAD(P)‐glycohydrolase in the streptomycyin‐producing Streptomyces griseus was investigated. Phospho‐adenosinediphospho‐ribose, the product of NAD(P)‐glycohydrolase reaction was shown to interfere as a competitive inhibitor not only with the glucose‐6‐phosphate dehydrogenase (Voronina et al. 1978) but also with the NADP‐dependent isocitrate and 6‐phospho‐gluconate dehydrogenases. Inhibition kinetics were studied with isocitrate dehydrogenase from pig heart and 6‐phosphogluconate dehydrogenase from yeast as well as with mycelial extracts of a mutant of S. griseus lacking NAD(P)‐glycohydrolase.
Study of inulase from Debaryomyces phaffii Capriotti
Authors: Demeulle S. , Guiraud J. P. , Galzy P. 
Published: July 2010

AbstractDebaryomyces phaffii posesses an inulinase activity which can be induced by growth on β‐fructosidase and particularly on inulin. The enzyme is located in the cell wall but is easily excreted into the culture medium. Maximum activity on inulin is observed at pH 4 and 50°C. The Km on inulin is 1.2 · 10−2 m. The enzyme breaks down inulin by splitting off terminal fructosyl units and it is active on sucrose and raffinose.
Regulation of phenol degradation in Pseudomonas putida
Authors: Janke D. , Pohl R. , Fritsche W. 
Published: July 2010

AbstractIn order to characterize the ability of Pseudomonas putida (Trevisan 1889) Migula 1895 strain H to degrade various mono‐ and diphenolic aromatic compounds, respiratory activities towards phenol, catechol, and the cresol isomers were determined. The following rates of oxygen uptake (Qo2) were obtained with resting phenol‐grown cells: phenol – 229, o‐cresol – 231, m‐cresol – 43, p‐cresol – 200, catechol – 262. All these compounds were oxidized by a two‐phase‐kinetics, the first phase is characterized by a higher oxidation rate than the second. The oxidation of phenol as well as of p‐cresol was found to be substrate‐inhibited at concentrations above 0.25 mM. A Ki‐value of 100 mg/I was calculated for phenol oxidation. The phenol‐degrading enzyme system is induced, probably coordinatively, by phenol and the cresol isomers. In strain H the degradation of phenol is carried out simultaneously with the assimilation of natural carbohydrates like glucose and sodium pyruvate. Aniline as well as sodium benzoate, though not metabolized by strain H, cause a concentration‐dependent inhibition of phenol degradation in resting phenol‐grown cells of that strain. The mechanism of this inhibition is discussed.
Möglichkeiten zur gezielten Manipulation der Genexpression des mikrobiellen Sekundärstoffwechsels
Authors: Gräfe U. 
Published: July 2010

AbstractThe present review deals with some theoretical and applied aspects of directed manipulations of control mechanisms governing the expression of microbial secondary metabolism. In attempting to make broad generalizations, the production of secondary metabolites is discussed in terms of the cellular differentiation of relevant organisms. On the basis of the actual information about the regulation of microbial idiolite synthesis, some potential ways for the quantitative and the qualitative improvement of secondary metabolite production are discussed. A number of examples demonstrate the effectiveness of rational strategies of strain development, e. g., the removal of non‐specific repressions of secondary metabolism by environmental factors, the excessive production of precursors due to altered control of intermediary metabolism, the increased resistance of producer organism against the autotoxicity of some idiolites, the deletion of alternative pathways of the primary and secondary metabolism, manipulations concerning the product spectrum, the deletion of feedback mechanisms, and elimination of degradating pathways in the secondary metabolism etc.The scope and limitations of rational strategies of strain improvement by genetic and physiologic manipulations are subjected to final discussion.
Further studies on a temperature‐sensitive mutant of Escherichia coli with defective repair capacity
Authors: Morfiadakis Irene , Geissler E. 
Published: July 2010

AbstractA temperature‐sensitive mutant of E. coli, WG24, was studied with respect to its sensitivity to photodynamic action, its capacity to perform host controlled reactivation, and its sensitivity to transduction at elevated temperatures. Mutant cells are much more sensitive than wild type cells to photodynamic action by thiopyronine and visible light at elevated temperatures. As well defined rec mutants, WG24 cells are less able to reactivate UV irradiated λc phages at elevated temperatures, while their ability to repair T1 phages is less impaired. Mutant cells cannot be transduced to T6 resistance at a detectable rate at elevated temperature. It is concluded, therefore, that some rec gene carries a ts mutation in this mutant.
Enzymes of glucose isomerization in various microorganisms
Authors: Suekane M. , Iizuka H. 
Published: July 2010

AbstractScreening tests for glucose‐isomerizing strains of various type, reference and laboratory strains of bacteria including actinomycetes, and yeasts were carried out. The ability to convert glucose to fructose was found to be widely distributed among various microorganisms. It was shown that glucose‐isomerizing ability was most prevalent in the genera Aerobacter and Escherichia, but was not found in the bacterial genera belonging to the order Pseudomonadales. Although their activities were not very high (probably due to unsuitable culture conditions) more than 70% of the actinomycetes and 60% of the yeasts grown on xylose possessed glucose‐isomerizing activity.
Zusammensetzung der Mikroorganismenpopulation im ungeschützten Fermentationsprozeß
Authors: Wünsche L. , Sattler K. , Gradova N. B. , Meinhold I. , Hedlich R. , Brendler W. , Uhlig H. , Rodionova G. S. , Saikina A. I. 
Published: July 2010

AbstractAn accompanying flora of the production strains always develops in each unprotected continuous fermentation process. In the process of production of fodder biomass from gas oil the high specific growth rate provides sufficient selection advantages to the production strain Lodderomyces elongisporus “D” EH 15 against substrate competitors. The accompanying flora uses products of metabolism and lysis as carbon and energy sources. The concentration of these compounds in the medium and consequently the development of the accompanying flora depends on the process conditions. During a period of more than ten years the taxonomic‐diagnostic and technological properties of the production strain Lodderomyces elongisporus “D” EH 15 did not change, caused by the permanent selection stress in the continuous fermentation process.
Microbiological implications of electric field effects III. Stimulation of yeast protoplast fusion by electric field pulses
Authors: Weber H. , Förster W. , Jacob H.‐E. , Berg H. 
Published: July 2010

AbstractPrototrophic colonies could be selected on minimal medium after mixing of protoplasts from diauxotrophic mutants of the yeasts Saccharomycopsis lipolytica and/or Lodderomyces elongisporus and treatment with polyethylene glycol (PEG) in the presence of calcium chloride. This is the result of protoplast fusion and complementation of auxotrophic deficiencies. Under identical conditions an electric field pulse in the μs‐range applied via an electric discharge to the protoplast‐PEG mixture resulted in a drastic enhancement of the protoplast fusion rate. The presence of polyethylene glycol was demonstrated to be a prerequisite for fusion in this case, too. The frequency of hybrid formation detected as prototrophic colonies could be increased in the case of intraspecific fusion at initial electric field strengths between 2.5 and 5 kV · cm−1. The application of an electric field pulse of proper strength and duration to a yeast protoplast suspension turned out to be a more effective tool in production of fusion products than conventional methods. Large numbers of parasexual hybrids for different selection programmes in yeast genetics and for industrial purpose may be delivered by this technique.
Einsatz der automatischen Bildanalyse beim Screening von leistungsfähigen Selektanten Turimycin‐bildenderStreptomyces‐Stämme
Authors: Mühlig P. , Freysoldt Christiane , Bradler Gertraud , Kühne Ch. 
Published: July 2010

AbstractThe growth of the surface colonies on solid media is studied with the image analyzing system QUANTIMET 720 M controlled by a PDP 11 computer. For the bacterial strainStreptomyces hygroscopicusJA 6599 a new differential equation describing the kinetic behaviour of the area of the colony is suggestedIt is shown that this time dependence of area describes more realistically the experiment than the function resulting from PIRT'S model. Two new constants arise from the growing curve, α describes the profile of density of the colony andk0is correlated to the growing constant of the colony. Both parameters can be correlated to the amount of antibiotics produced and, therefore, it is possible to use this information for the selection procedure of the colonies. A uniform criterion for selection was found for each colony of two mutants of the turimycin‐producing strainStreptomyces hygroscopicusJA 6599, which reads:The quality of the selection criterion of surface colonies with higher productivity is dependent on the mean value of the growing parameters of all colonies under investigationLimitations of the selection method arise from the need for great uniformity of environmental conditions, growth medium and a homogeneous spore suspension, which have to consist of a large amount of single spores in order to assure a reproducible growing curve of the colonies. For the last condition a special technique is pointed out.
Enzyme induction in Streptomyces hydrogenans. Comparison of the effects of different steroids to increase the activity of 3α, 20β‐hydroxysteroid dehydrogenase and of 3β, 17β‐hydroxysteroid dehydrogenase
Authors: Bauer Brigitte , Träger L. 
Published: July 2010

AbstractAfter cultivation of Streptomyces hydrogenans in the presence of different steroids the activity of both 3α,20β‐hydroxysteroid dehydrogenase and 3β, 17β‐hydroxysteroid dehydrogenase was determined in the cell homogenate of the microorganism. By comparing the efficacy of the steroids to increase enzyme activities, steroids could be divided into 3 groups: a) steroids which stimulated preferentially the activity of 3α,20β‐hydroxysteroid dehydrogenase (e. g., corticosterone), b) steroids which stimulated preferentially 3β,17β‐hydroxysteroid dehydrogenase (estradiol‐17β), and c) those behaving intermediately (e. g., progesterone, 5α‐dihydrotestosterone). Highest 3β, 17β‐hydroxysteroid dehydrogenase activity could be measured 2 h after addition of 5α‐dihydrotestosterone to the culture medium. The activity of 3α, 20β‐hydroxysteroid dehydrogenase, however, increased continuously up to 4 h. 3α,20β‐hydroxysteroid dehydrogenase and 3β,17β‐hydroxysteroid dehydrogenase syntheses seemed to be controlled by steroids in a non‐coordinate manner.
β‐1.3.‐1.4‐Glucanase in spore‐forming microorganisms. VI. Genetic instability of β‐glucanase production in a high‐producer strain of Bacillus amyloliquefaciens grown in a chemostat
Authors: Borriss R. , Noack D. , Geuther R. 
Published: July 2010

AbstractA Bacillus amyloliquefaciens strain high‐producing for β‐1.3‐1.4‐glucanase has gradually lost the ability to produce this enzyme during long‐time continuous cultivation, independent of the culture conditions. Mutant strains isolated after long‐term cultivation exhibited changed behavior concerning extracellular enzyme formation and sporulation. By agarose gel electrophoresis of alkaline DNA extracts isolated from original and mutant strains we demonstrate that the observed pleiotropic phenomena are not caused by the loss of a complete plasmid present in the original strain. From extracts of both the original and mutant strains plasmid DNAs with approximately the same molecular weight of about 35 Mdal were isolated.
Effect of medium treatment on microbial degradation of sterols by Nocardia
Authors: Komel R. 
Published: July 2010

AbstractThe rate of transformation of cholesterol by Nocardia sp. is affected by the culture medium composition as well as by the way it has been treated before inoculation. When 1% of peptone was sterilized separately and afterwards added to the basic medium, the transformation of cholesterol to bisnorchola‐1,4‐dienic acid, as well as further aerobic degradation, was accelerated by a factor of 2. If this enriched medium was kept at rest overnight, the rate of transformation was lowered to half. Heating of additional peptone together with a basic medium resulted only in a slight diminution of the transformation of the preceding 4‐ene metabolite to the final 1,4‐diene when compared with a normal basic medium without any additive.
Growth characteristics and ultrastructure of protoplast type L‐forms from Streptomycetes
Authors: Gumpert J. 
Published: July 2010

AbstractL‐form colonies from S. hygroscopicus, S. griseus and S. levoris were isolated after incubation of lysozyme protoplasts on an osmotically stabilized complex agar medium. Unstable and stable L‐forms grow on solid and in liquid media. L‐form colonies are 5–10 times smaller than normal colonies and show a typical morphology for each species. In ultrathin sections L‐form cells are characterized by nucleoid areas with typical core‐like structures, by a ribosome‐rich cytoplasm with different inclusion bodies, and by a cytoplasmic membrane. Because there are no cell wall structures L‐forms of the three Streptomyces species belong to the protoplast type.Analysis of cell size and cell shape shows a variation in diameter and a cell propagation by regular and irregular division‐ and budding‐like processes. Many L‐form cells contain more than two chromosomes.The results are discussed with regard to the cellular organisation of streptomycetes and the nature of the stable L‐form.
Antimicrobial activities of daunorubicin and adriamycin derivatives on bacterial and protoplast type L‐from cells of Bacillus subtilis 170, Escherichia coli B, and Proteus mirabilis VI. Structure — activity relationship
Authors: Gumpert J. , Dornberger K. , Smith T. H. 
Published: July 2010

AbstractThe antibacterial activity of ten N‐alkylated derivatives of daunorubicin and adriamycin as well as of 5‐iminodaunorubicin has been tested by using Bacillus subtilis 170, Escherichia coli B, and Proteus mirabilis VI and their stable protoplast type L‐forms in an agar diffusion test. Eight of the substances showed similar activities against B. subtilis and the L‐forms of all test organisms, but no activity against the bacterial forms of E. coli and P. mirabilis. The cell wall of these gram‐negative bacteria is responsible for this resistance by not allowing the antibiotics to enter the cells. The piperidino compound N‐(CH2)5 daunorubicin shows 2‐4 times higher activity against R. subtilis and all L‐forms in comparison to daunorubicin and the other derivatives. Five of the substances were inactive against all test strains. Their inactivity seems to be associated with the larger substituents at the C‐3′ position. Relations between molecular structure and activity are discussed considering data about the interaction with DNA and the antitumor activity. Stable protoplast type L‐forms and their bacterial forms represent a suitable and effective test system to screen for more effective substances and to get more information about their mode of action.
Enzymatische Untersuchungen zur Citrat‐Isocitrat‐Akkumulation bei Hefen mit Glucose als C‐Quelle
Authors: Franke‐Rinker D. , Behrens U. , Nöckel E. 
Published: July 2010

AbstractThe connection between the kinetics of citrate‐isocitrate overproduction bySaccharomycopsis lipolyticain glucose media and the specific activities of the enzymes being related to overproduction has been investigated. The specific activities of citrate synthase, aconitate hydratase, NAD+‐ linked and NADP+‐linked isocitrate dehydrogenase decline significantly after exhaustion of the nitrogen source, whereas the activity of the pyruvate carboxylase remains relatively constant and corresponds to changes of the production rate. The results are compared with those obtained by fermentations inn‐alkane media and discussed in relation to mechanisms of overproduction.
Nucleosidpolyphosphate: Vorkommen, Metabolismus und Funktion
Authors: Riedel K. 
Published: July 2010

AbstractProcaryotes have regulatory systems allowing to vary the metabolism in response to nutritional variations, to reduce the growth, and to start development. Nucleoside polyphosphates are mediators of coordinated alterations of metabolism.In this review, after a brief recall of the characteristics of the stringent response, the occurrence, determinations, and the metabolism of the nucleoside polyphosphates are presented. The representation of the pleiotropic effects includes the regulation of the protein synthesis and of the protein synthesis apparatus, of the protein turnover, of the N‐ and carbohydrate metabolism, of the formation of cell membranes and cell walls as well as the possible function of the development.
Effektorwirkung von sauerstoffhaltigen C1‐Verbindungen bei der Kultivierung des methanotrophen Bakterienstammes GB 25
Authors: Schneider J. D. , Wendlandt K.‐D. , Brühl E. , Mirschel G. 
Published: July 2010

AbstractAddition of oxygen‐containing C1‐compounds to chemostat cultures of GB 25 increases both the yield of biomass and the specific growth rate. At optimum concentrations the catalytic activity of these compounds increases with increasing growth rates. Their influence on maintenance coefficients and maximum yield coefficients decreases in the order CH3OH > CO2 > HCOOH > HCHO. This result together with spectrophotometric NADH determinations suggests that the NADH pool determines the balance between the assimilatory and oxidative utilization of formaldehyde.