bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cellulolytic activity of aerobic soil actinomycetes
Authors: Lamot E. , Voets J. P. 
Published: July 2010

AbstractThe cellulolytic activity of several aerobic soil actinomycetes against insoluble cellulose and soluble cellulose derivatives (CMC‐carboxymethylcellulose) was studied.From the soil, 8 actinomycete strains were isolated after enrichment growth and purification on the same synthetic medium.The actinomycete strains were able to degrade insoluble cellulose, with the production of cellobiose and various oligosaccharide intermediates as degradation products, indicating the random attack of the cellulose chain.The actinomycete strains showed also a great activity against soluble cellulose (CMC). The viscosity of CMC solutions decreased rapidly and was followed by an increase in reducing compounds.The degree of substitution of CMC solutions had an effect on the degradation by the actinomycetes. The degree of polymerization did not affect the rate of hydrolysis, however.
Remarques sur la régulation des métabolismes de Candida utilis LODDERet KREJER VAN RIJ
Authors: Pons G. , Guiraud J. , Galzy P. 
Published: July 2010

AbstractCandida utilis has a strong fermentative metabolism, that is more important than respiratory activity. This species is characterized for a strong PASTEUR effect and for absence of glucose effect.
Veränderungen der Aktivität von Aminoacyl‐tRNS Synthetasen (AAS) während unterschiedlichen Zellteilungsverhaltens des natürlichen Filamentbildners Kurthia zopfii
Authors: Süss J. , Walraph E. , Mach F. 
Published: July 2010

AbstractIn der vorliegenden Arbeit konnte gezeigt werden, daß im natürlichen Entwicklungszyklus von Kurthia zopfii Filamente, Langstäbchen und Kurzstäbchen entstehen, wobei die zellteilungsaktiven Phasen beim Übergang vom Filament zum Langstäbchen und schließlich zum Kurzstäbchen jeweils von höheren Aktivitäten der Aminoacyl‐tRNS Synthetasen (AAS) begleitet sind. Obwohl andere physiologische Parameter im Filament ihre Maximalwerte erreichen, ist die AAS‐Aktivität in Kurzstäbchen 104% und in Langstäbchen 12% höher als in Filamentextrakten (0,1 mg Protein/Standardansatz der ATP‐32(PP)i‐Austauschreaktion). Die Km‐Werte für ATP betragen analog zu diesen Befunden für die 9 im Gemisch untersuchten AAS für Kurzstäbchen 6,2 × 10−4 M/1, für Langstäbchen 7,1 × 10−4 M/1 und für Filamente 9,1 × 10−4 M/1.
Größenveränderungen des Spindelplaques bei Saccharomyces fragilis
Authors: Unger E. 
Published: July 2010

AbstractSpindle plaques of Saccharomyces fragilis are morphometrically analysed. Their diameters increase when the middle part of the nucleus associated organell disappears. Later, when their distance is more than 600 nm, the heights also increase. Simultaneously an ultrastructural change of one of the spindle plaques takes place. These events are discussed in relation with plaque DNA replication and with their ability (in complex with microtubules and mitochondria) to control nuclear movement.
Production physiology and properties of a novel fungal fibrinolytic enzyme
Authors: Fayek K. I. , Foda M. S. , Naggar M. R. El 
Published: July 2010

AbstractA potent extracellular fibrinolytic enzyme was obtained from cultures of the imperfect fungus Fusarium semitectum under certain growth conditions. Nitrate addition to cultures increased enzyme production. The enzyme showed a versatile proteolytic activity against several protein substrates including casein, gelatin, haemoglobin, bovine serum albumin, and fibrin from both buffalo and human sources.Optimal fibrinolysis occurred at pH values around 7.0. The fibrinolytic activity exhibited marked heat stability in enzyme samples heated to 60 °C, and retained more than 40% of its activity in samples heated to 100 °C for 10 min. Fibrinolysis proceeded optimally in the temperature range between 50–60 °C. Copper ions significantly activated the enzyme. Other biochemical properties are also reported.
Metal accumulation by bacteria with particular reference to dissimilatory sulphate‐reducing bacteria
Authors: Jones H. E. , Trudinger P. A. , Chambers L. A. , Pyliotis N. A. 
Published: July 2010

AbstractDissimilatory sulphate‐reducing bacteria, genera Desulfovibrio and Desulfotomaculum, exhibit a superior ability, over assimilatory organisms, to extract trace amounts of metals from culture media. This property does not appear to be solely a function of the presence of H2S. In media containing elevated amounts of Fe, electron dense particles, provisionally identified as FeS, are deposited within the cells of dissimilatory bacteria.
Restriktion und Modifikation bei Staphylococcus aureus: Eigenschaften von Resistenzplasmiden und Prophagen
Authors: Witte W. 
Published: July 2010

AbstractExperiments on elimination and transfer of resistance‐plasmids in S. aureus (controlling resistance to penicillin, chloramphenicol and oxytetracycline) show that these plasmids have no restricting influence on phages used for typing of staphylococci. Prophages in lysogenic strains control a mechanism of restriction and modification which is active on phages and on chromosomal markers. The resistance‐plasmids used in these experiments are insensitive to prophage controlled restriction.
Spaltung des α‐L‐Arabinofuranosids, β‐D‐Glucopyranosids und β‐Cellobiosids von 4‐Nitrophenol durch Enzyme verschiedener Pilze — ein Beitrag in Verbindung mit Versuchen zur Steigerung der Selektivität der Tumortherapie
Authors: Butschak G. , Förster W. , Graffi A. 
Published: July 2010

AbstractTo carry out long‐term experiments as part of a therapy concept of malignant tumours using inactive transport forms of cancerostatic substances and their specific cleavage in the acidic pH region of the tumours by application of extraneous enzymes, we require enzymes with similar catalytic and pharmacokinetic properties which differ from each other in immunological respect. In the search for such enzymes, the α‐L‐arabinofuranosidases from 12 different fungi, among them 9 basidiomycetes, were studied. The enzymes mentioned were demonstrable in all fungi. Optimum pH values ranged between 2.5 and 5.5. The Km values for the cleavage of α‐L‐arabinofuranoside were, in most cases, 0.5 to 1.8 moles · liter−1 · 10−3. With regard to pH dependence, the α‐L‐arabino‐furanosidases of most of the fungi investigated proved adequate for the long‐term trials envisaged.4‐nitrophenyl‐β‐D‐glucopyranoside and ‐β‐cellobioside were also cleaved by enzyme preparations of all the 11 fungi investigated. The β‐D‐glucopyranosidases showed a less favourable pH dependence than the α‐L‐arabinofuranosidases. The cleavage of 4‐nitrophenyl‐β‐cellobioside, on the contrary, showed mostly a comparatively favourable pH dependence. On the basis of the coinciding optimal pH values and the occurrence of 4‐nitrophenyl‐β‐D‐glucopyranoside as an intermediate product in the cleavage of the corresponding cellobioside, we assume that both substrates are cleaved by β‐glucosidase. Because the occurrence of the glucoside during the cleavage of cellobioside is undesirable for the therapeutic trial, a method is proposed for selection of an appropriate cellobioside splitting enzyme basing on the present studies and the relevant literature.
Influence of cations on the membrane potential of Chlorella fusca
Authors: Langmüller G. , Springer‐Lederer H. 
Published: July 2010

AbstractThe influence of the chlorides of K, Na, Ca, Zn, Cd, Pb, and Ce on the membrane potential of Chlorella fusca (SHIHIRA et KRAUSS) 211‐8 b, Göttingen, has been studied. The potential depended on the concentration of Na und K much less than predicted by the GOLDMAN equation. The dependence on the concentrations of Ca, Zn, and Cd was qualitatively similar to that in the case of the alkali ions. With Pb and Ce, the potential was entirely suppressed already at moderate concentrations, i. e., in the millimolar range. The contrast between the effects of the inessential elements Cd and Pb on the potential corresponds to the difference between their paths of uptake.The dependence of the membrane potential on time has also been studied. With K, Na, and Ca stationary states were reached within about 1 hour. The time course of the depression of the potential by Pb depended on the concentration. At moderate concentration, suppression could be partly reversed by subsequent treatment of the cells with diluted KCl.
Assimilatory nitrate reductase in a chlorate‐resistant mutant of Escherichia coli
Authors: Motohara K. , Kobayashi Miya , Ishimoto M. 
Published: July 2010

AbstractNitrate reductase was investigated in extracts from cells of a chlorate‐resistant mutant strain of E. coli which grew anaerobically on nitrate as the sole source of nitrogen. The nitrate reductase was of particulate nature and reduced chlorate like the nitrate reductase from the wild strain, but in contrast was inhibited only weakly by azide or cyanide.Nitrate reductase activity was found in extracts from the mutant cells grown on nitrate as the sole source of nitrogen, but not in extracts from cells grown in complex nutrient medium. Addition of ammonia also caused a decrease in activity. Accordingly, the nitrate reductase in the chlorateresistant mutant is of the assimilatory type.
Degradation of sulphur nucleotides in cell‐free extracts of Thiobacillus ferrooxidans
Authors: Tuovinen O. H. , Kelley B. C. , Nicholas D. J. D. 
Published: July 2010

AbstractThe cell‐free extracts of Thiobacillus ferrooxidans contain hydrolytic enzymes which cleave sulphate from either adenosine 5′‐sulphatophosphate or adenosine 3′‐phosphate 5′‐sulphatophosphate. These sulphatase activities may be retarded by including either phosphates or adenine nucleotides in the incubation mixtures. Adenosine 3′‐phosphate 5′‐sulphatophosphate and its immediate breakdown product adenosine 3′‐phosphate 5′‐phosphate were degraded at slower rates than adenosine 5′‐sulphatophosphate.
Manganoxydierende Bakterien III. Wachstum und Manganoxydation bei Pseudomonas manganoxidans SHW.
Authors: Jung W. K. , Schweisfurth R. 
Published: July 2010

AbstractUntersuchungen über allgemeine Kulturbedingungen für Pseudomonas manganoxidans ergaben, daß die optimale Mn(II)‐Konzentration in der Flüssigkultur bei 5 bis 10 mg/l liegt. Bei höheren Konzentrationen wird die Manganoxydation stark beeinträchtigt. Zusätze von Calcium haben einen positiven Einfluß, während NH4+ bereits in niedrigen Konzentrationen die Manganoxydation hemmt. Dieser Effekt macht sich auch bei Wachstum auf aminosäurehaltigen Nährmedien infolge der Bildung von NH4+ durch fehlende Manganoxydation bemerkbar.Untersuchungen zum Wachstumsverlauf ergaben, daß das Wachstum in Gegenwart von Mn(II) und durch dessen Oxydation nicht beeinflußt wird. Die Manganoxydation setzt erst am Ende der exponentiellen bzw. am Anfang der stationären Wachstumsphase ein. Manganoxydation durch Luftsauerstoff bei höheren pH‐Werten (ab 8,0) konnte ausgeschlossen werden.Einbauversuche mit 14CO2 zeigten, daß bei manganoxydierenden Zellen keine autotrophe CO2‐Fixierung stattfindet. Ribulose‐1,5‐diphosphat‐Carboxylase wurde nicht nachgewiesen.Bei ständiger Zufuhr geringer Mengen an abbaubarer organischer Substanz können manganoxydierende Bakterien sich auch ohne Nutzung der freien Energie aus der Manganoxydation in den von ihnen gebildeten Manganoxiden anreichern.
Effects of polyamines and analogs on staphylococcal nuclease
Authors: Yanagawa H. , Ogawa Y. , Egami F. 
Published: July 2010

AbstractThe promoting activity of polyamine analogs (IV ∼ XV) on staphylococcal nuclease with DNA as the substrate was compared with that of natural polyamines (I ∼ III):
NH2(CH2)3NH(CH2)4NH(CH2)3NH2 (spermine);
NH2(CH2)3NH(CH2)3NH(CH2)3NH2 (thermine);
NH2(CH2)4NH2 (putrescine);
CN(CH2)2NH(CH2)4NH(CH2)2CN;
HOOC(CH2)2NH(CH2)4NH(CH2)2COOH;
VI. C2H5OOC(CH2)2NH(CH2)4NH(CH2)2COOC2H5;
VII. HO(CH2)3NH(CH2)4NH(CH2)3OH;
CH3CONH(CH2)3NH(CH2)4NH(CH2)3NHCOCH3;
IX. C2H5NH(CH2)3NH(CH2)4NH(CH2)3NHC2H5;
NH2(CH2)3S(CH2)4S(CH2)3NH2;
NH2(CH2)3NH(CH2)2O(CH2)2NH(CH2)3NH2;
NH2(CH2)3NCH3(CH2)4NCH3(CH2)3NH2;
CN(CH2)2NCH3(CH2)4NCH3(CH2)2CN;
(CH3)2N(CH2)3NCH3(CH2)4NCH3(CH2)3N(CH3)2;
NH2(CH2)2O(CH2)2NH2
Replacement of the terminal groups by CN, COOH, COOEt, NHAc, NHEt, or N(CH3)2 remarkably decreased the activity.The compound VII with terminal hydroxyl groups had a lower promoting activity at low concentrations, but revealed higher activity at higher concentrations and, in contrast to spermine, no inhibition at all even at very high concentrations.Replacement of both internal amino groups by sulfur or NCH3 decreased the activity.The introduction of an ether bond into the internal methylene groups (compound XI) highly decreased the activity.Based upon these findings the possible relationship between structure and activity is discussed.
Bewertung der Produktion von Glykosiden des ϵ‐Pyrromycinons (Galirubine) bei der Züchtung des Stammes Streptomyces galilaeus
Authors: Královcová E. , Tax J. , Blumauerová M. , Vanêk Z. 
Published: July 2010

AbstractEs wurde eine Methode zur routinemäßigen Bestimmung von Glykosiden des ϵ‐Pyrromycinons (Galirubine) in Submerskultur von Streptomyces galilaeus ausgearbeitet. Ihr liegt eine saure Hydrolyse der Galirubine, eine Extraktion des Hydrolysates mit einem nichtpolaren Lösungsmittel und eine spektrophotometrische Bestimmung des frei gewordenen ϵ‐Pyrromycinons im Extrakt zugrunde.
Eine Stempelplattenmethode zur quantitativen Aufgliederung von gemischten Bakterienpopulationen nach der Abhängigkeit des Wachstums von der Salzkonzentration
Authors: Thormann D. , Näveke R. 
Published: July 2010

AbstractEine Methode wird beschrieben, die es gestattet, unter Verwendung der Stempelplattentechnik nach LEDERBERG eine gemischte Bakterienpopulation quantitativ in Gruppen hinsichtlich ihres Wachstumsverhaltens gegenüber verschiedenen Salzkonzentrationen aufzugliedern. Sie erfordert weniger Arbeits‐ und Materialaufwand als bisher verwendete Methoden. Die Methode wurde auf drei verschiedene natürliche Standorte angewendet: Meerwasser, Flußwasser und ein kleines flaches, stehendes, salzhaltiges Gewässer. Sie erscheint im Prinzip auch für die Aufgliederung einer Mischpopulation hinsichtlich der Beeinflussung des Wachstums durch andere Faktoren geeignet.
Wirkungsmechanismus von Terrazol bei Mucor mucedo
Authors: Lyr H. , Casperson G. , Laussmann B. 
Published: July 2010

AbstractIt is assumed that the fungistatic effect of terrazol in Mucor mucedo is induced by a liberation of phospholipases within the mitochondria and perhaps at other membranes. In isolated mitochondria a rapid formation of lysolecithin can be demonstrated at low concentrations of terrazol. This would explain the lytic symptoms in mitochondria visible by electron microscopy. Lipid peroxidation could not be demonstrated. The only antidots at present known for the growth inhibiting effect of terrazol and on its ultrastructural effects are impure saccharose, which seems to contain an unknown factor, and procain hydrochloride or to a lesser extent lidocain, which are well‐known inhibitors of phospholipases. The pathologigal thickening of the cell wall induced by terrazol seems to be an unspecific side effect reflecting a diminished phosphorylating activity of the mitochondria.
Untersuchungen zum transient‐Verhalten ammoniumlimitierter Chemostatenkulturen vonEscherichia coliML 30
Authors: Müller P. J. , Bergter F. 
Published: July 2010

AbstractIn connection with the bistability of pyruvate formation in ammonium limited continuous cultures ofE. coliML 30 (BERGTER u. ROTH 1977) the transient behaviour of cell density and pyruvate concentration were studied. Immediately after a shift up in the dilution rate fromD= 0.15 h−1toD= 0.6 h−1the bacteria excreted pyruvate into the medium, followed by a resumption of pyruvate. The specific pyruvate formation rate as well as the specific growth rate reached the new steady state with damped oscillations. Possibly the excretion of pyruvate after the shift is caused by the higher non limiting concentrations of ammonium during the first of the transition. This hypothesis is supported by the transient behaviour of an ammonium limited continuous culture after a pulse of ammonium to the culture. The relations between ammonium metabolism and pyruvate formation are discussed.
Wechselwirkungen zwischen Aminoacyl‐tRNS Synthetasen (AAS) und Zellteilung bei einer temperatursensitiven filamentösen Mutante von Bacillus subtilis SB 19 III. Charakterisierung des Vorinkubationseffektes und Einfluß eines AAS‐Inhibitors aus Agrostemma githago‐Keimlingen
Authors: Süss J. , Hecker M. 
Published: July 2010

Further results on the correlations between the regulation of bacterial cell division and aminoacyl‐tRNA synthetase are presented. Activity of aminoacyl‐tRNA synthetases, extracted from a filamentous mutant of Bacillus subtilis SB 19, may be stimulated by preincubation of crude extracts.The mechanism of this stimulating effect has been studied by means of an inhibitor of aminoacyl‐tRNA synthetases produced during the growth of Agrostemma githago‐seedlings. According to preliminary results we suggest, this inhibitor can reduce the activity of subunits only, but not that of higher associates. Association of subunits to oligomers will be prevented by the inhibitor, too. Our results may be indicative of the assumption that the increase of enzyme activity during preincubation of bacterial extracts, eliminated by the inhibitor, is changed by the association of subunits with a low catalytic activity to functional oligomers.As to the verification of these hypotheses further work will still have to be done.
Combined mutagenesis by UV light and nitrosomethylurea of Streptomyces hygroscopicus spores
Authors: Frunder B. , Noack D. , Rontó Gy. 
Published: July 2010

AbstractBy means of combined treatment with UV light and nitrosomethylurea (NMU) the spores of Streptomyces hygroscopicus were mutagenized. The rate of the colony‐forming survivals exhibited two phases depending on the duration of NMU treatment.The slope of the first phase is interpreted as the result of alkylation of purin bases without repair functions. The slope of the second phase is discussed on the basis of a different content of plasmid DNA within the cells.Following the mutagenic treatment the growth rate of the colonies diminished. This effect is quantitatively measured by the aid of an automatic picture analyzer. The size distribution of the colony diameters showed two peaks in the control indicating that the Streptomyces spores grew up with one or two mycelium tubes resulting in two different growth rates.With increasing duration of NMU treatment the colonies with high diameters disappeared in favour of colonies with small diameters.By mathematical comparison it could be shown that a cooperative effect exists between the action of UV light and NMU on DNA. The spores containing DNA damages as a result of cooperative effects give rise to a distinct class of colony size. With the aid of an automatic picture analyzer it will be possible to select very effectively the desired mutants.
Regulative influence ofo‐aminobenzoic acid on the biosynthesis of nourseothricin in cultures ofStreptomyces nourseiJA 3890b II. Regulation of glutamine synthetase and the role of the glutamine synthetase/glutamate synthase pathway
Authors: Gräfe U. , Bocker H. , Thrum H. 
Published: July 2010

AbstractInS. nourseiJA 3890b which produces nourseothricin, a streptothricin‐type antibiotic, the participation of the glutamine synthetase/glutamate synthase pathway in the regeneration of glutamic acid was established.Glutamate synthase of this organism requires 2‐ketoglutarate, glutamine, and NADH for glutamate production. The glutamine synthetase/glutamate synthase pathway is considered to operate both in the assimilation of low levels of ammonia and in the nitrogen catabolism of amino acids,e. g.of alanine.Thus, the activity of glutamine synthetase increased in cultures grown on a soluble medium after the pool of NH+4was exhausted. The synthesis of this ‘assimilative’ type of enzyme was found to be repressed by increased amounts of ammonium ions in the medium.High intramycelial levels of glutamine synthetase even in the presence of high concentrations of ammonium ions were found if the strain was cultivated on a medium containing an additional source of nitrogen,e. g.alanine or some other amino acids. Simultaneously, in these cultures the activity of alanine dehydrogenase was enhanced, suggesting that this enzyme cooperates with the ‘amphibolic’ type of glutamine synthetase in the catabolism of amino acids. o‐Aminobenzoic acid (OAB, anthranilic acid) a known stimulator of the biosynthesis of nourseothricin byS. nourseiJA 3890b was shown to exert a repressory effect on the formation of both the ‘amphibolic’ type of glutamine synthetase and the alanine dehydrogenase. The capacity ofo‐aminobenzoic acid to regulate diverging pathways of amino acid metabolism was further demonstrated by its stimulatory effect on the production of NADP‐specific glutamate dehydrogenase.
Effect of nitrate reduction on metabolic products and growth of Propionibacterium acidi‐propionici
Authors: Kaneko Mayumi , Ishimoto M. 
Published: July 2010

AbstractFrom a culture of P. acidi‐propionici (formerly P. arabinosum) in a medium containing lactate and nitrate, a strain with high activity of nitrate reduction was isolated and used in this study. The growth rates on lactate and glucose were not significantly affected by nitrate under anaerobic and aerobic conditions. Addition of nitrate resulted in a decrease of propionate and an increase of acetate and pyruvate produced from lactate and glucose with accumulation of nitrite. In the reaction of cell suspensions in the absence of added nitrogeneous nutrient, a similar result was obtained. Accumulation of large amounts of polysaccharide observed in the presence of glucose under these conditions was not affected by the addition of nitrate. The molar growth yield on lactate but not on glucose in a defined medium was increased in the presence of nitrate. In cell suspensions glycerol, glucose, lactate, and propionate were utilized as electron donors for nitrate reduction to nitrite. Nitrate reduction was also found in cells grown in the absence of nitrate. Cytochrome b, found in the organism, was reduced by lactate and oxidized by nitrate or by fumarate in cell suspensions and in cell‐free extracts.
Induktion der NADP+‐abhängigen Aldehyddehydrogenase durch Kohlenwasserstoffe bei Acinetobacter calcoaceticus
Authors: Aurich H. , Eitner G. 
Published: July 2010

AbstractAcinetobacter calcoaceticus bildet beim Wachstum auf längerkettigen n‐Alkanen oder 1‐Alkanolen eine NADP+‐abhängige Aldehyddehydrogenase, wenig dagegen auf Fett‐ oder Aminosäuren. Das Enzym hat am Ende der logarithmischen Phase seine höchste spezifische Aktivität. Die Induktion des Enzyms kann durch Chloramphenicol oder Puromycin verhindert werden. Als Induktoren wirken auch mittelkettige 1‐Alkanole (Hexanol, Heptanol, Octanol) und Alkanale (Octanal), obwohl sie nicht als C‐Quelle dienen können. Die Aldehyddehydrogenase wird nach der Übertragung von einem n‐Alkan‐ auf ein Hefeextrakt‐Medium von den sich vermehrenden Zellen in 2 Std. um fast 60% abgebaut, in nicht‐wachsenden Zellen beträgt der Abbau nur etwa 20%.