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  • 1
    ISSN: 1432-072X
    Keywords: New antibiotic from actinomycetes ; RNA-synthesis inhibitor ; Tirandamycin B
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Ein Stamm von Streptomyces flaveolus, Tü 1240, bildet neben dem schon länger bekannten Tirandamycin A das Tirandamycin B, das sich durch eine zusätzliche Hydroxylgruppe von A unterscheidet. Beide Antibiotica besitzen ein ähnliches Wirkungsspektrum und offensichtlich gleichen Wirkunsmechanismus. Anhand der Daten aus der Massenspektrometric, der 13C-und 1H-NMR-Spektren läßt sich dem Tirandamycin B die Formel II zuordnen.
    Notes: Abstract Streptomyces flaveolus, strain Tü 1240 produces besides Tirandamycin A, a hitherto unknown antibiotic, which is closely related to Tirandamycin A. The new antibiotic Tirandamycin B contains one additional hydroxylgroup. Both antibiotics exhibit a similar antimicrobial spectrum and they seem to have the same mechanism of action. According to the data obtained from mass spectrometry, 13C-and 1H-NMR spectra formula II could be deduced for Tirandamycin B.
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  • 2
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    Electronic Resource
    Springer
    Archives of microbiology 115 (1977), S. 323-331 
    ISSN: 1432-072X
    Keywords: Aspergillus viridi-nutans ; Ferricrocin ; Feed-batch cultivation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract At low iron(III)-concentrations (〈10-5 M) the fungus Aspergillus viridi-nutans Ducker & Thrower excretes desferri-ferricrocin as the main sideramine into the culture medium. While this compound accounts for 95% of the sideramines produced, small amounts of additional sidermines may also be detected. In a search for an inexpensive nutrient medium for optimum production of desferri-ferricrocin, experiments using shake flasks with good aeration were undertaken initially. The best medium conditions were then employed in a fermentor system. In a 20-1 fermentor with “intensor” system, it was shown that at certain growth rates there was an inverse correlation between rate of growth and rate of sideramine production. A defined nutrient medium of glucose plus acetate as carbon sources, and urea or ammonium acetate as nitrogen sources was used. Two different feeding regimens were used in response to changes of pH or to changes of partial pressure of oxygen in the submerged culture: acetic acid/urea of acetic acid/ammonium acetate additions regulated these conditions. The rate of sideramine production under such feeding achieved a maximum of 20 mg l-1 h-1 over a period of several days.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 26 (1957), S. 307-328 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Zusammenfassung Unter den 18 von Pridham u. Gottlieb (1948) vorgeschlagenen C-Quellen sind l-Rhamnose, Raffinose, l-Xylose, d-Fructose, l-Arabinose und d-Mannit für die Charakterisierung von Streptomyces-Arten am besten geeignet. Mit Hilfe der Ergebnisse von l-Rhamnose und Raffinose lassen sich die untersuchten Stämme in 4 Gruppen (I–IV) aufteilen. Die Gruppe III (l-Rhamnose und Raffinose negativ) kann an Hand der Ergebnisse von l-Xylose, d-Fructose und l-Arabinose in 5 Untergruppen (IIIa-IIIe) aufgeteilt werden. Die Besprechung der einzelnen Gruppen zeigt, daß in keinem Fall die C-Quellen-Spektren allein zur Artbestimmung ausreichen.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 39 (1961), S. 158-194 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The macrolide-antibiotics are discussed in respect to their chemistry and biology. The single substances are listed. An investigation and classification of the streptomycetes producing macrolides, is added; the single species are critically revised. Relations are established between the producers and their products.
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  • 5
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Pseudomonas fluorescens scheidet bei Anzucht unter Eisenmangel ein Polypeptid in die Nährlösung aus, das mit Ferri-Ionen einen stabilen Komplex bildet. Dieser Eisenkomplex, Ferribactin genannt, stellt ein Dihydroxamat dar und gehört zu den Siderochromen. Ferribactin enthält mindestens die folgenden Bausteine: Je 1 Mol Glycin, L-Serin, d-Serin, L-Glutaminsäure, δ-N-Hydroxy-L-ornithin, δ-N-Hydroxy-d-ornithin, d-Tyrosin, 3 Mol L-Lysin und 2 Mol Essigsäure.
    Notes: Summary In iron free cultures Pseudomonas fluorescens secretes a polypeptide which reacts with ferric ions to form a stable complex. This iron complex called Ferribactin is a dihydroxamate and belongs to the Siderochromes. Ferribactin contains at least the following components: A mole each of glycine, L-serine, d-serine, L-glutamic acid, δ-N-hydroxy-L-ornithine, δ-N-hydroxy-d-ornithine, d-tyrosine, 3 moles of L-lysine and 2 moles of acetic acid.
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  • 6
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    Electronic Resource
    Springer
    Archives of microbiology 61 (1968), S. 143-153 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Es wurde die Wirkungsweise von Borrelidin untersucht und mit zwei Makrolid-Antibiotica verglichen. Borrelidin hemmt in einem zellfreien System aus Bacillus subtilis spezifisch den Einbau von Threonin in sRNS bei einer Konzentration von 1,4·10-6 m. Hingegen hemmen die Makrolid-Antibiotica Lankamycin (neutral) und Erythromycin (basisch) bei Konzentrationen, die zehnmal höher liegen als die wachstumshemmende Konzentration, nicht die Verknüpfung von Threonin oder anderer Aminosäuren mit sRNS. In Zellen hemmt Borrelidin bei einer Konzentration von 1,5–3·10-6 m die Synthese von Protein, RNS und DNS. Lankamycin und Erythromycin hingegen hemmen nur die Synthese von Protein. Es wird vermutet, daß Borrelidin das erste Antibioticum ist, das die Protein-synthese über die Hemmung des Einbaus von Aminosäuren in sRNS blockiert.
    Notes: Summary The mode of action of borrelidin has been studied and compared with two macrolide antibiotics. Borrelidin specifically inhibits the attachment of threonine to sRNA at a concentration of 1,4·10-6 m in a cell-free system of Bacillus subtilis. However, the macrolide antibiotics lankamycin (neutral) and erythromycin (basic), at concentrations which are ten times higher than those required to inhibit growth, still do not inhibit the binding of threonine or other amino acids to sRNA. In cells borrelidin inhibits at concentrations of 1.5–3·10-6 m the synthesis of protein, RNA and DNA. In this point as well borrelidin acts differently from lankamycin and erythromycin which inhibit the synthesis of protein selectively. It is supposed that borrelidin is the first antibiotic inhibiting protein synthesis via amino acid attachment to sRNA.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 67 (1969), S. 156-165 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Boromycin, at a concentration of 0.05 μg/ml inhibits the synthesis of protein, RNA and DNA in whole cells of Bacillus subtilis. It is being antagonised by surface active compounds and is being bound to lipoprotein. Binding of the boromycin within the cell especially takes place at the cytoplasmic membrane. The inhibitory effect to Bacillus subtilis is being reversed by high concentration of potassium salts (e.g. 0.2 m KCl). The reversion is specific of potassium salts. After the adding of boromycin a discharge of potassium ions from the cells can be observed. The K+-Na+-activated ATP-ase of the cytoplasmic membrane is not influenced by boromycin. On an artificial membrane of carbon tetrachloride boromycin shows a low selectivity for potassium ions compared with sodium and lithium ions. The degradation of boromycin through alkaline and acid hydrolysis leads to a loss of antibiotic activity, due to the splitting off the boric acid from the molecule.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 82 (1972), S. 55-65 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Alle getesteten Verbindungen (Ferrioxamine, Sideramine vom Ferrichrom-Typ außer Ferrichrom A, Fusigen, Coprogene, Dihydroxamsäuren, Monohydroxamsäuren außer Fusarinin, Eisencitrat, Eisen-EDTA, Hämin und Hämproteine) fördern das Wachstum von Microbacterium lacticum. Die vier zuerst genannten Gruppen sind besonders hoch und etwa gleich wirksam. Auch bei Microbacterium lacticum ist das Sideramin-Bedürfnis von der Einsaatdichte abhängig. Im Antagonismustest zeigen die Sideramine unterschiedliche Wirkung, je nachdem ob der Test auf der Agarplatte oder in Submerskultur durchgeführt wird, und auch in Abhängigkeit von dem Testkeim und dem Sideromycin. Die größte Spezifität hat der Kreuztest, bei dem außer den Trihydroxamaten nur Terregensfaktor und Dimerumsäure aktiv sind. Die Ergebnisse deuten darauf hin, daß wachstumsfördernde und Sideromycinantagonisierende Wirkung der Sideramine auf zwei verschiedenen Mechanismen beruhen.
    Notes: Summary All compounds tested (ferrioxamines, sideramines of the ferrichrome type except ferrichrome A, fusigen, coprogens, dihydroxamates, monohydroxamates except fusarinine, iron citrate, iron-EDTA, hemin and hemoproteins) promote the growth of Microbacterium lacticum. The first four groups mentioned are of high and nearly equal activity. As in other cases the sideramine requirement of Microbacterium lacticum is inoculum dependent. In the antagonism test, the sideramines are of different activity whether the test is done on an agar plate or in submers culture and is also dependent on the test organism and the sideromycin. The specificity is highest in the agar diffusion test where only terregens factor and dimerum acid are active besides the trihydroxamates. The results seem to indicate that in the growth promoting and the sideromycin-antagonizing action of the sideramines two different mechanisms are operative.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 88 (1973), S. 49-60 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Mit einer Ornithinmangelmutante von Neurospora crassa, arg-5, ota, aga, deren Sideraminbildung vollständig blockiert ist, wurde die Aufnahme von verschiedenen Sideraminen und von Eisencitrat untersucht. Ferrioxamin oxamin B sowie N-Acetyl-ferrioxamin B (Ferrioxamin D1) und N-Benzoyl-ferrioxamin B werden von Neurospora-Zellen nicht angereichert. Die transportkinetischen Daten zeigen, daß Neurospora crassa unter Eisenmangelbedingungen zwei voneinander differenzierbare Eisentransportsysteme ausbildet: das Coprogensystem und das Eisencitratsystem.
    Notes: Summary With an ornithine-deficient mutant of Neurospora crassa, arg-5, ota, aga, whose sideramine production is completely blocked, the uptake of various sideramines and iron citrate was studied. Ferrioxamine B, as well as N-acetyl-ferrioxamine B (ferrioxamine D1) and N-benzoyl-ferrioxamine B were not accumulated by the cells of Neurospora. The kinetic data of transport indicate, that under iron-deficient conditions Neurospora evolves two distinguishable iron-transport systems: the coprogen system and the iron citrate system.
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  • 10
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The Zygomycete Cunninghamella elegans produces the polycarboxylate siderophore rhizoferrin. Production depends mainly on iron concentration in the medium. With an optimized production medium the yield of rhizoferrin in a bioreactor could be increased to more than 4 g/l. Supplementation of the basic production medium with different precursors led to the formation of nine new rhizoferrins. Both the diaminobutane backbone and the citric acid side-chains of rhizoferrin could be substituted by appropriate analogues. These substitutions led to new siderophores either with a variable length of diamine bridge or with fewer or different functional groups. The proportion of the new diamine analogues relative to the total rhizoferrin could be markedly increased by the use of α-difluoromethylornithine, an inhibitor of the ornithine decarboxylase.
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