bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wirkung von Polyen‐Makrolidantibiotica auf normale und zellwandlose Zellen vonEscherichia coliW1655F+
Authors: Haupt Ina , Schuhmann Edith , Geuther R. , Thrum H. 
Published: July 2010

AbstractThe polyene macrolide antibiotics are active against yeasts, fungi, and other eukaryotic cells, but are with a few exceptions inactive against bacteria. The resistance of bacteria against these compounds is usually explained by the absence of sterols in their cells, the target sites of polyene antibiotics.However, in our experiments with mycotrienin, nystatin, tetramycin, lucensomycin, rimocidin, filipin, lagosin, flavofungin, flavomycoin, antibiotic 2814 P, antibiotic 5001 P, and candicidin it was demonstrated that bacteria may be susceptible to polyene antibiotics, too, if the wall‐less stable protoplast type L‐form ofE. coliW1655F+is used. The measured growth inhibition concentrations were comparable with those of typical antibacterial antibiotics.Our experiments have shown that the normal rod form and the wall‐less L‐form ofE. coliW1655F+contain traces of sterols in nearly the same concentration range. This means that the selective sensitivity of the L‐form cannot be explained by higher sterol content of these cells in comparison to the resistant normal rod form cells. We assume that the bacterial cell wall is responsible for the resistance of the normal rod form by masking internal target sites.
Einfluß definierter Substrat‐Limitationen auf das Enzym‐und Metabolitmuster des methylotrophen BakteriumsPseudomonasW 6
Authors: Hofmann K. , Sawistowsky J. , Babel W. 
Published: July 2010

AbstractDer Zusammenhang zwischen Milieubedingungen und der Konzentration zentraler Stoffwechselintermediate sowie der Konzentration bzw. der Aktivität von Enzymen des Citratzyklus und der Synthese von Glutamat wurden bei dem obligat methylotrophen BakteriumPseudomonasW 6 untersucht.Die Konzentrationen der Glutamatdehydrogenase, der Isocitratdehydrogenase, der Glutamat‐Oxalacetat‐Transaminase und NADH‐Oxidase ändern sich in der stationären Wachstumsphase gegenüber der exponentiellen praktisch nicht und sind unabhängig von der Art der Limitation (NH4+, Methanol, O2). Dagegen steigt die Aktivität der Glutaminsynthetase erwartungsgemäß an, wenn die stationäre Phase durch NH4+‐Mangel eingeleitet wird.Glycerinaldehyd‐3‐phosphat, Dihydroxyacetonphosphat und Isocitrat konnten unabhängig von den Mangelbedingungen in keinem Fall mit Hilfe enzymatischer Bestimmungsmethoden nachgewiesen werden. Die zellulären Konzentrationen an Pyruvat und α‐Ketoglutarat steigen unter NH4+‐Mangelbedingungen um das 2‐ bzw. 70 fache an, unter Methanol‐Mangelbedingungen ändern sich die Konzentrationen gegenüber der exponentiellen Phase nicht. Das Anstauen von α‐Ketoglutarat wird als ein weiterer Beweis für den offenen Citratzyklus beiPseudomonasW 6 diskutiert. Die hohe Pyruvatkonzentration und die geringe Aktivität des Pyruvat‐Dehydrogenase‐Komplexes deuten darauf hin, daß dieses Enzym für den Citratzyklus “key enzyme” — Funktion besitzt.
Physiologischer Zustand von Bacillus megaterium im Chemostaten unter alkalischen Bedingungen
Authors: Ivanova I. I. , Shaforostova L. D. , Sakharova Z. V. , Hilliger M. 
Published: July 2010

AbstractEs wurde der Einfluß alkalischer Kultivierungsbedingungen (pH > 7,0) auf Bacillus megaterium im Chemostaten mit Glucose und Citrat als C‐Quellen untersucht. Die Erhöhung des pH‐Wertes bis zu einem für jede Verdünnungsrate charakteristischen Schwellenwert verursacht eine deutliche Erhöhung des Verbrauchs der zweiten, nicht limitierenden C‐Quelle Glucose und somit eine Verringerung des gemeinsamen Ertragskoeffizienten Y. Die Bestimmung der spezifischen Rate m des Erhaltungsstoffwechsels für Citrat und Glucose zeigte, daß der erhöhte Verbrauch der Glucose beim pH‐Schwellenwert außer durch eine erhöhte Produktbildung (SAKHAROVA et al. 1976) durch einen erhöhten Erhaltungsstoffwechsel verursacht wird. Die Aktivität von Schlüsselenzymen des Katabolismus (Glucose‐6‐Phosphatdehydrogenase, Isocitratdehydrogenase, Malatdehydrogenase, Pyruvatdehydrogenase) sowie der ATP‐Gehalt der Zellen nimmt beim pH‐Schwellenwert ab. Die bei einer Verdünnungsrate von D = 0,4 h−1 bestimmte ATPase‐Aktivität zeigt beim pH‐Schwellenwert einen erhöhten Wert.
Wachstum von Bacillus megaterium im Chemostaten unter alkalischen Bedingungen
Authors: Sakharova Z. V. , Shaforostova L. D. , Hilliger M. , Perewesjenzev W. P. 
Published: July 2010

AbstractDie Kultivierung von Bacillus megaterium im Chemostaten unter alkalischen Bedingungen (pH > 7,0) zeigte, daß dieser Stamm in einem weiten pH‐Bereich wächst. Dieser pH‐Bereich verkleinert sich mit zunehmender Verdünnungsrate D im Chemostaten. Eine Erhöhung des pH‐Wertes über einen bestimmten, für jede Verdünnungsrate charakteristischen Schwellenwert hinaus verursacht schnelles und vollständiges Auswaschen der Kultur. Vergleichende Untersuchungen bei pH 7,0 und beim pH‐Schwellenwert zeigten beim pH‐Schwellenwert einen erhöhten Verbrauch der zweiten, nicht limitierenden C‐Quelle Glucose, eine Ausscheidung von organischen Säuren ins Nährmedium und eine Verringerung des gemeinsamen Ertragskoeffizienten Y für Citrat und Glucose. Die pro Gramm gebildete Trockenmasse verbrauchten Mengen von Phosphor und Stickstoff zeigten beim pH‐Schwellenwert im Vergleich zur Kontrolle (pH 7,0) keine Veränderung.
Testing of antiviral compounds against Mengo virus infection of mice A 2‐step procedure of in vivo screening
Authors: Veckenstedt Anneliese , Horn M. 
Published: July 2010

AbstractA 2‐step procedure of screening of antiviral compounds in vivo is presented on the basis of standardized methods of both experimental examination and statistical analysis. The procedure uses the “rate of protection” R as the sole criterion of activity. In the first step, requiring a total of 40 mice, compounds with significant R are detected. Drugs producing R < 15% are discarded. Compounds eliciting R ⩾ 15%, without significance, are examined in a second step, using again 40 mice, to decide whether the protective activity becomes significant employing a greater number of animals. The procedure works with relatively less expense with regard of the number of animals used and the time required. The procedure can be applied to test systems based on lethal infections as well as to test models for which the use of the “rate of protection” is relevant.
Keratin decomposition by dermatophytes II. Presence of S‐sulfocysteine and cysteic acid in soluble decomposition products
Authors: Kunert J. 
Published: July 2010

AbstractThe dermatophyte Microsporum gypseum was grown on human hair in a mineral medium. Filtrates of cultures of various age were chromatographed on Sephadex gels and further characterized by chemical analysis and thin‐layer chromatography. The products of keratin decomposition were separated into two fractions. The first fraction formed 10 to 20% of the bulk and contained proteins low in sulfur content. The second, very wide fraction contained oligopeptides and polypeptides with molecular weights from several hundreds up to approximately 13,000 with a peak at 1,000–2,000 daltons. This fraction contained a relatively high amount of cystine, S‐sulfocysteine, and cysteic acid.S‐sulfocysteine was present in the free state and also combined in peptides where its amount exceeded that of cystine. This supports the author's hypothesis on keratin decomposition by dermatophytes. According to this hypothesis, the fungus excretes sulfite which cleaves the disulfide bonds of keratin to cysteine and S‐sulfocysteine. The substrate, denatured by sulfitolysis, is then more easily digestible by fungal proteases.Besides S‐sulfocysteine, comparable amounts of cysteic acid were found in all analyses. This compound most probably originated by air oxidation of sulfur amino acids in the alkaline cultivation fluid.
Influence of substrate moisture on the occurrence of fungi in birds' nests
Authors: Hubálek Z. 
Published: July 2010

AbstractThe nests of birds examined were identical to those of the previous study (HUBÁLEK 1976) but the number of the nests of Black‐headed Gull (11 samples only) was lower. Therefore, the total number was 186 nests in the collection „A”︁ and 84 in the collection „B”︁. The methods of investigation were the same as applied in the preceding study; water content of the samples was estimated in duplicate or triplicate by drying the material 3 hours at 105 °C, and expressed on the wet weight basis.
Mutagenesis in bacteriophage T 7. II. UV induced mutagenesis
Authors: Meyer M. , Witte W. 
Published: July 2010

AbstractUV induced mutagenesis of bacteriophage T 7 was investigated by using a forward mutation system (host range system) and a back mutation system (amber system). The results indicate a dependence of mutation of T 7 after UV irradiation only on the rec gene controlled functions of the bacterial host. The functions controlled by pol and uvr genes have no influence. Among other types of mutations UV irradiation leads to transitions from AT to GC.
Das anodisch wandernde thermolabile Antigen (ATA) von gramnegativen Bakterien: Seine molekulare Heterogenität und seine chemische Zusammensetzung
Authors: Reissbrodt R. , Kemmer G. , Seltmann G. 
Published: July 2010

AbstractThe anodically‐moving thermolabile antigen (ATA) of gram‐negative bacteria represents a glycolipoprotein. In aqueous solution ATA exhibits heterogeneity of the molecular size, the range varying between 2 · 104 and 8 · 105 Daltons. In the molecular range between 5 · 104 and 8 · 105 all the molecular states give precipitation lines with the corresponding antisera.It could be shown that all the molecular states of ATA are formed by different aggregation of the same subunit with a molecular weight of approximativly 22 000.
Variability of polyploid strains of Candida scottii in accumulation of riboflavin in the medium
Authors: Imshenetsky A. A. , Kondratieva T. F. 
Published: July 2010

AbstractPolyploid strains of Candida scottii show a higher spontaneous and UV‐induced variability in accumulation of riboflavin in the medium than the original haploid strain. UV irradiation affects the formation of variants and induces those which accumulate more riboflavin than any of the most productive variants resulting from spontaneous variability. In the polyploid strains the frequency of plus‐variants increases. Therefore, polyploid strains of C. scottii are advantageous for selection processes.
Physiologie und Biochemie der Streptomyceten IX. Hydrolyse von Cyclohexyl‐, Kohlenhydrat‐ und Arylester durch eine Carboxylesterase aus Kulturen von Streptomyces hygroscopicus JA 6599
Authors: Reuter G. , Hüttner R. 
Published: July 2010

AbstractCarboxylesterase in cell‐free extracts of Streptomyces hygroscopicus was characterized with cyclohexylacetate and β‐penta‐acetyl‐D‐glucose as substrates. After concentrating the enzyme, activity with α/β‐methyl‐4‐O‐propionyl‐L‐mycarosid as substrate was also observed. The influence of enzyme effectors was studied. Esterase activity was also found in the culture filtrate of. S. hygroscopicus.
Abhängigkeit der spezifischen Wachstumsrate von der Ammoniumkonzentration bei Escherichia coli ML 30
Authors: Bergter F. , Schumann H. , Koburger M. 
Published: July 2010

AbstractThe transient behaviour of ammonium limited continuous cultures of E. coli ML 30 led to the hypothesis that the bistability of pyruvate formation primarily is caused by a bistability of the ammonia metabolism. Therefore, a function μ([NH+4]) should be expected different from that of MONOD type. Measurements of the specific growth rate during washout of continuous cultures at different ammonium concentrations and at such low cell concentrations that the changes in the ammonium concentration of the medium could be neglected, showed a complex function with a relative minimum near 2 mg/1 NH+4. This function allows bistability of the ammonium concentration in an ammonium limited continuous culture. The results are discussed on the basis of the two systems of ammonia assimilation found in prokaryotic cells.
Some characteristics of two morphological mutants of Nostoc linckia induced by nitrosoguanidine
Authors: Ladha J. K. , Kumar H. D. 
Published: July 2010

AbstractThe blue‐green alga Nostoc linckia was treated with nitrosoguanidine and two classes of morphological mutant clones were isolated. One class shows certain abnormal phenotypic features of vegetative cells, spores, and heterocysts. It has increased heterocyst frequency and impaired growth rate. The other class exhibits an altered heterocyst spacing pattern. Both classes of mutants have reduced nitrogenase activity.
Glycinabhängigkeit von Staphylococcus aureus‐Stämmen
Authors: Voigt W. , Seltmann G. 
Published: July 2010

AbstractGlycine dependent Staphylococcus aureus var. bovis strains (TSCHÄPE and RISCHE 1971) were tested for their ability to grow on glycine containing and glycine deprived media. We observed glycine dependence only in minimal media. In complete media the strains grew in absence of glycineTesting the ability of some glycine precursors we found that in minimal media glycine could be replaced by threonine and in some cases by serine. One mutant (Gly 100 Glyox.r.) was able to metabolize glyoxylate instead of glycineAspartic acid was metabolized in presence of glycine. Using 14C‐aspartic acid we detected 14C‐glycine and 14C‐threonine. Presumably the bacteria metabolize aspartic acid to glycine via threonine.
Enzymes of carbohydrate metabolism in Coprinus cinereus (C. lagopus sensu LEWIS)
Authors: Fawole M. O. 
Published: July 2010

AbstractThis report describes the detection by spectrophotometric assays of all the enzymes involved in the breakdown of glucose to pyruvate via the EMBDEN‐MEYERHOF‐PARANAS pathway as well as some enzymes of the hexose monophosphate pathway in cell‐free extracts of Coprinus cinereus.
Reinigung von DNS‐Polymerase aus Proteus mirabilis
Authors: Nüske R. , Bieber J. , Wähnert U. , Venner H. 
Published: July 2010

AbstractAus Proteus mirabilis PG 273 wird durch mechanischen Aufschluß, Fällung mit Streptomycinsulfat, Autolyse und fraktionierte Fällung mit Ammoniumsulfat eine DNS‐Polymerase gewonnen. Ihre weitere Reinigung wird durch fraktionierte Alkoholfällung und Chromatographie an DEAE‐Cellulose erreicht. Die enzymatischen Eigenschaften des Präparates werden untersucht. Das Enzym gibt eine de novo‐Synthese von poly‐dAT, wie auch DNS‐Polymerase I aus Escherichia coli. Allerdings sind die Reaktionsprodukte noch dialysabel. Es kann nachgewiesen werden, daß es sich um eine DNS‐Polymerase I handelt.Vergleichsuntersuchungen mit einer polA‐Mutante zeigen, daß das Aufarbeitungsverfahren auch zur Isolierung von Restmengen bakterieller DNS‐Polymerase I geeignet ist.
Fruchtkörper‐bildende Myxobakterien in Böden Brasiliens
Authors: Dawid W. 
Published: July 2010

AbstractAus 5 Großgebieten Brasiliens wurden 36 Bodenproben entnommen und nach vier verschiedenen Isolierungsmethoden auf Fruchtkörper‐bildende Myxobakterien untersucht. Je Bodenprobe wurden 100 Einzelproben angesetzt, insgesamt 3636.Es wurden 19 verschiedene Fruchtkörper‐bildende Myxobakterien‐Arten isoliert und nach BERGEY (MCCURDY 1974) bestimmt. Sie gehören folgenden 7 Gattungen an: Myxococcus mit 5 Arten, Archangium mit 3 Arten, Cystobacter mit 2 Arten, Polyangium mit 4 Arten, Melittangium mit 1 Art, Stigmatella mit 2 Arten. Chondromyces mit 2 Arten.Zu den häufigsten und weitverbreiteten Myxobakterien gehören die Arten M. fulvus, M. coralloides und A. gephyra, zu den selten beobachteten die Arten A. flavum, Stigm. erecta, Stigm. aurantiaca, Ch. apiculatus und Ch. pediculaius.Artenzahl und Häufigkeit der gefundenen Myxobakterien werden in Beziehung zur Isolierungsmethode und zum Herkunftsgebiet der Bodenproben gesetzt.
Fine structure of imbibed sclerotial cells of Claviceps purpurea (Fr.) Tul revealed by freeze‐etching
Authors: Streiblová Eva , Rýc M. , Kybal J. 
Published: July 2010

AbstractThe fine structure of the cortex of the natural sclerotium of Claviceps purpurea was studied. The cell wall of sclerotial cells is thickened due to overproduction of the fibrillar component of the wall. The intercellular spaces of the cortex tissue form a continuous system which is apparently instrumental in mediating communication between the growing sclerotium and the external milieu. The cytoplasmic membrane of imbibed sclerotial cells carriers abundant signs of secretory activity. Secretion vesicles, the content of which is discharged into external space, apparently contain exo 1,3‐glucanase. Cytoplasmic vesicles migrating toward the plugged pores of the thickened septa apparently involve hydrolase secretion too. Spherosomes with lipid content are a predominant component of the cytoplasm of sclerotial cells. The activity of the membrane systems of imbibed cells indicates that the mobilization of lipids sets in only after activation of the hydrolases. Findings of phagocytosis of lipid granules by vacuoles are relatively frequent so that lipolysis might proceed in the vacuoles. Alkaloids could not be detected with the aid of freeze‐etching.
Virus‐like particles in yeast: Isolation and infectivity
Authors: Nesterova G. F. , Kärner J. , Soom Yo. , Kozlova T. M. 
Published: July 2010

AbstractVirus‐like particles containing electron dense cores are seen in thin sections of intact and degenerated cells of a thermosensitive (ts) strain of Candida tropicalis. A particulate fraction not present in wild‐type cells has been isolated from the ts cells disrupted by pressure. The particles are 80‐120 nm in diameter. Empty particles with a central cavity are observed. The method of infecting mating pairs of Saccharomyces cerevisiae by partially purified particles is described.
Characterization of the virulent actinophage S2
Authors: Klaus S. , Süss F. , Juch C. , Hauck A. 
Published: July 2010

AbstractThe virulent actinophage S2 isolated from soil infects Streptomyces hygroscopicus 6599, S. lividans 66, and S. levoris 1331. Morphology of S2 was studied by electron microscopy. Influence of growth medium and temperature on multiplication of S2 has been studied qualitatively. S2 is more sensitive to UV irradiation on strain 66 than on 1331. In contrast to UV, hydroxylamine mutagenesis delivered 9 stable ts mutants which belong to 3 complementation groups.Most of the ts mutations isolated on 1331 were found to be host dependent. 8 of 9 mutants were found to be able to grow at 40 °C on strain 66 but none of them on 1331. Moreover 2 of the mutants were found to be much more heat sensitive in 6599 than in 1331, as indicated by the changes in half‐life temperatures.The latent period of S2+ depends on temperature and germination state of the spores. Under optimal conditions we found 140 min. Ts2 and ts7 have been classified as a late and ts17 as an early mutant.
RhodosporidiumBANNO: Dosiseffektbeziehungen, Mutageneffektivität und Mutantenspektrum bei der Induktion Auxotrophie verursachender Mutationen durch ultraviolettes Licht und N‐Methyl‐N′‐nitro‐N‐nitrosoguanidin
Authors: Böttcher F. , Samsonova I. A. 
Published: July 2010

AbstractThe kinetics, efficiency, and specificity of induction of forward mutations to auxotrophy by ultraviolet light (UV) and N‐methyl‐N′‐nitro‐N‐nitrosoguanidine (MNNG) was examined in stationary phase cells ofRhodosporidium(Rhodotorula) wild strain Rgl.In comparison to the spontaneous level the frequency of auxotrophic mutants was increased more than 1000 times by both mutagens, however, the mutagenic efficiency of MNNG was higher than that of UV. We found that the forward mutation rate is a linear function of the applicated UV and MNNG doses in the range to 600 J m−2or 25 mm x min, respectively.The 35 studied biosynthetic pathways to amino acids, purines, pyrimidines, and vitamins are genetically blocked at different frequencies, but there is not any significant difference between UV and MNNG induced frequencies of mutants with a specific requirement. However, in difference to the approximately equal distribution of the MNNG‐inducednicmutants among the genetic blocks of the tryptophan‐nicotinamide pathway, UV‐inducednicmutants occurred with a higher frequency in the genes of the tryptophan pyrrolase and the 3‐hydroxykynureninase than in the genes of the other enzymes of the pathway.
Hemmung der Chitin‐Synthetase von Mucor rouxii in vitro durch Fungicide und andere Wirkstoffe
Authors: Lyr H. , Seyd W. 
Published: July 2010

AbstractComparative investigations on the inhibition of chitin synthetase of Mucor rouxii revealed that in contrast to results obtained in vivo, only few fungicides and other compounds inhibit the enzyme in vitro. Besides the well‐known effect of polyoxin D, an inhibition was demonstrated for terrazol, tridemorph, hinosan, and formulated preparations of dimilin (PH 60‐40, 60‐38). The latter preparations, however, showed growth inhibition also with fungal species which do not synthesize chitin and the pure compounds are ineffective.Inhibition by phospholipase C, unsaturated fatty acids, and the reversibility of the inhibition caused by terrazol after addition of procain‐hydrochloride demonstrates that phospholipids are essential for the activity of the enzyme, whereas sterols seem to be ineffective. Action of trypsin, PCNB, pentachlorophenol, and some similar compounds results in significantly increased activity, which in the case of trypsin could be due to the hydrolysis of a protein inhibitor. Hinosan inhibits the enzyme indirectly in a still unexplored manner.
Manganese oxidation by an intracellular protein of a Pseudomonas species
Authors: Jung W. K. , Schweisfurth R. 
Published: July 2010

AbstractCultures of a Pseudomonas sp. strain MnB 1 produce an intracellular, managanese oxidizing protein (abbrev. as Mn ox. protein) during the stationary phase of growth. This protein is heat labile, can be inactivated by protease and has a pH‐optimum for manganese oxidation at pH 7.0. Mn2+ is oxidized only at concentrations below 3 · 10−5 M. The occurrence of the protein is not dependent on the presence of Mn2+, but is clearly related to the cessation of growth after the end of the exponential growth phase Oxygen, coenzymes, and low molecular weight components of the cell extract seem not to be involved in the rection as electron acceptors for the oxidation of Mn2+. Continued managanese oxidation by Mn ox. protein results in a progressive decrease in activity which corresponds to the amount of formed manganese oxide.
Steroidumwandelnde Enzyme aus Mikroorganismen IX. Affinitätschromatographische Präparation und Untersuchung des Apoenzyms einer 4‐En‐3‐oxosteroid: (Akzeptor)‐1‐en‐oxidoreduktase aus Nocardia opaca
Authors: Atrat P. , Deppmeyer V. , Hórhold C. , Móller L. 
Published: July 2010

AbstractFrom the flavoenzyme, 4‐en‐3‐oxosteroid: (acceptor)‐1‐en‐oxidoreductase of Nocardia opaca, prosthetic group and apoenzyme were separated quantitatively by means of affinity chromatography in the presence of 2 M (NH4)2SO4 at pH 3.0. Subsequently the apoenzyme was eluted from affinity matrix by 0.01 M phosphate buffer, pH 8.0, whereas under these conditions the intact enzyme could not be eluted. The whole enzyme activity applied could be restored by incubation of the eluted apoenzyme with FAD. The binding strength of the apoenzyme to the immobilized steroid ligand is highly decreased in comparison to the native enzyme and can be interpreted by the action of rest hydrophobicity. That indicates the essential character of FAD for both ligand binding and transformation.
Influence of pesticides on the growth of cyanobacteria
Authors: Hutber G. N. , Rogers L. J. , Smith A. J. 
Published: July 2010

AbstractTwo unicellular and two filamentous cyanobacteira (blue‐green algae) were exposed under conditions optimal for photoautotrophic growth to eleven pesticides. Low concentrations (0.01 to 5 ppm) of diuron, atrazine, and paraquat inhibited growth. With MCPA, MCPP, 2,4‐D, milstem and ethrel, marked inhibitory effects were achieved only at concentrations above 100 ppm. Growth was inhibited by glyphosat, DDT, and thiram at intermediate concentrations. In some cases, the effective concentration of the pesticide varied considerably with the organism tested.