摘要:

Abstractα‐Amylase of the thermophilic actinomyceteThermomonospora vulgariswas partially purified. Maximal enzyme activity was obtained at 60 °C and pH 6.0. KMvalue was 1.4%. The effect of some metal salts on enzyme activity was studied. Enzyme activity was inhibited by KCN, EDTA, and iodoacetate. Inhibition by EDTA was completely nullified by CaCl2, but the inhibition by iodoacetate was not overcome by 2‐mercaptoethanol. Exposure of the enzyme to pH 7.0 and 9.0 for 2hr. did not affect the enzyme, but exposure to pH 3.0 for few minutes completely inactivated the enzyme. Exposure of the enzyme to 60 °C resulted in an appreciable inactivation and exposure to 80 °C completely inactivated the enzyme. Addition of CaCl2, 2‐mercaptoethanol, or enzyme substrate did not stabilize the 60 °C exposed enzyme. However, bovine serum albumin had a protective effect when the enzyme was exposed to 60 °C but not to 80 °C. The enzyme was stable in the presence

ISSN:0044-2208    

DOI:10.1002/jobm.19750150602

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractA stable spheroplast type L‐form could be isolated by transferring 627 single colonies and 195 agar blocks with several colonies of unstable L‐forms ofProteus mirabilisD 52 on agar media without supplements of penicillin. The L‐form grows well on complex and synthetic agar media, however, it failed to grow in any of the liquid media which have been proved. With one exception (formation of acid from maltose) the L‐form shows the same biochemical activities like the parent rod‐shaped bacterium. However, the insensitivity for various phages and the failure of DAP in the envelopes demonstrate that there are profound alterations in the biosynthesis and structure of the murein and of the outer wall layers. The results of these investigations and an ultrastructural analysis (GUMPERT and TAUBENECK 1975) show that the stable spheroplast type L‐form LD 52B ofProteus mirabilismust be considered as a true cell enve

ISSN:0044-2208    

DOI:10.1002/jobm.19750150603

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractResistomycin preferentially inhibits RNA synthesis in comparison to DNA and protein synthesis in intact bacterial cells. Studies with cell‐free systems have shown that the antibiotic interferes with DNA and RNA synthesis, while protein synthesis is inhibited to a much lesser extent. Detailed studies in cell‐free systems indicate an interaction of resistomycin with DNA‐ and RNA polymerase. In the case of RNA polymerase this was proved by CD measurements, whereas no interaction of the antibiotic with DNA, RNA, and homopolynucleotides could be found. One can conclude that the binding of the antibiotic to RNA polymerase is the basis for its interference with RNA synt

ISSN:0044-2208    

DOI:10.1002/jobm.19750150604

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe utilization ofn‐hexadecane byCandida lipolytica(strain 10) was studied with respect to the lipid content, phospholipid and fatty acid profiles resulting at various growth times. Thin layer chromatography of the lipid extracts showed quantitative changes in the different lipid classes. The phospholipid fraction obtained at each growth time was separated into 8 classes: lysophosphatidylcholine, sphingomyelin, phosphatidylcholine, phosphatidylethanolamine, glycophospholipid, phosphatidylglycerol, cardiolipin, and phosphatidic acid. Differences in the percentage fatty acid composition of the lipid extracts were observed at various stages of growth. The cellular fatty acids included palmitic, palmitoleic (35–52%), stearic, oleic, linoleic (26–39%), and pentadecanoic (2–12%) as major components. This indicates that fatty acid(s) of the same length as that of the substrate was the most abundant component, thus showing intact incorporation mechanism. Fatty acids having longer chain lengths were also formed in substantial amounts indicating C2addition and β‐oxidation of the fatty acids formed in

ISSN:0044-2208    

DOI:10.1002/jobm.19750150605

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractDie Eigenschaften und der Einfluß von organischen Säuren und Nucleotiden auf die Aktivität der hoch‐ (ICD I) und niedermolekularen (ICD II) NADP+‐abhängigen Isocitratdehydrogenase ausAcinetobacter calcoaceticuswerden untersucht.Beide Formen des Enzyms unterscheiden sich in ihren Affinitäten zum Isocitrat, zum NADP+und zu Mn++‐Ionen. Die ICD I ist gegenüber 2,0 M Harnstoff stabil, nach Inkubation des Enzyms bei 40° kommt es aber schon nach kurzer Zeit zu einem deutlichen Aktivitätsabfall. Die ICD II verhält sich gegen Harnstoff und Hitze genau umgekehrt.α‐Ketoglutarat und Oxalacetat hemmen, Pyruvat und Glyoxylat aktivieren nur die ICD I. Gleichzeitige Zugabe von Oxalacetat und Glyoxylat hemmt beide Formen des Enzyms. Durch AMP und ADP wird nur die ICD I aktiviert. ATP hemmt — in unterschiedlichem Grad

ISSN:0044-2208    

DOI:10.1002/jobm.19750150606

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractParomomycin was isolated from culture filtrates ofStreptomyces albus var. metamycinus nov. var.after feeding the growing cultures with D‐glucose‐u‐14C. From the different incorporation rates conclusions concerning different features of the paromomycin biosynthesis (utilization of the carbon source, proportional and disproportional changes of the rates of synthesis) could be drawn. Uptake and metabolism of glucose are disc

ISSN:0044-2208    

DOI:10.1002/jobm.19750150607

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractA temperature‐sensitive strain (HD 20) ofSalmonella typhimuriumis described. At restrictive temperature this strain shows an envelope alteration and a defect in division associated with an increase in cell diameter. On a shift to 42 °C there is residual division forca.30 min and then no further increase in cell number. In minimal medium (MM) at 42 °C cell diameter remains unchanged for about one mass doubling and then increases. From measurements of cell elongation, it is concluded that such increases in diameter occur because cell volume increases exponentially at 42 °C but increases in the rate of elongation occur for only a short period and then elongation rate becomes constant. This conclusion is supported by the observation that HD 20 cells show no increase in diameter at 42 °C when cultured in media supplemented with sucrose and Mg++; normal increases in elongation rate occur in such media. A model which fits the experimental data has been constructed. This model has two main features namely (1) the elongation of individual cells is linear with the rate of elongation doubling close to division and (2) such doublings in elongation rate are linked to division such that division cannot occur if elongation rate has not doubled shortly before. In the mutant it is proposed that only a few doublings in elongation rate occur at 42 °C and these are responsible for the residual division. The model fits the data for cultures shifted to 42 °C in MM or in yeast extract casamino acids MM (YE Cas MM) and for cultures shifted to 42 °C and shifted up from MM to YE Cas MM. The observations on these medium shifted cultures suggest that the activity of growth zones responsible for elongation is medium d

ISSN:0044-2208    

DOI:10.1002/jobm.19750150608

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractBeiA. calcoaceticus69‐V wird nach Ultraschallaufschluß im zellfreien Rohextrakt ein Pyridin‐nucleotid‐unabhängiges Enzym zur Oxydation von längerkettigen primären aliphatischen Alkoholen nachgewiesen. Als Testsubstrate wurden Hexanol und Octanol verwendet. Als Elektronen‐akzeptor kann Dichlorphenolindophenol dienen. Der entstehende Aldehyd wird als Phenyl‐hydrazon identifiziert und quantitativ gemessen. DCIP‐Abnahme und Hydrazonzunahme ent‐sprechen sich. Das pH‐Optimum der Reaktion liegt bei 7,5. Phenazinmethosulfat hat keinen Einfluß auf die Reaktionsgeschwindigkeit. Die spezifische Aktivität des Enzyms liegt nach Wachstum aufn‐Alkanen etwa bei 4 nMol/min/mg Protein; nach Wachstum auf Äthanol ist das

ISSN:0044-2208    

DOI:10.1002/jobm.19750150609

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19750150610

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19750150611

出版商:Akademie‐Verlag    

年代:1975

数据来源: WILEY