Role of phosphatases in the biosynthesis of chlortetracycline inStreptomyces aureofaciens

ATP diphosphohydrolase activity and inorganic pyrophosphatase reached two maxima during cultivation of the low- and high-producing variant ofStreptomyces aureofaciens under conditions of phosphate limitation,i.e. after 30 and 70 h of cultivation. Increased levels of inorganic phosphate in a medium inhibitory to biosynthesis of chlortetracycline markedly decreased the levels of both enzymes. The ATP diphosphohydrolase activity was detected both in the supernatant and membrane fractions of the cell-free preparation of the mycelium.     

UeberPetasites Kablikianus Tausch

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Nachträgliches überStipa Tirsa Steven

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Die Vermehrung der Sporangien vonGinkgo biloba L.

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Die Vermehrung der Sporangien vonGinkgo biloba L.

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Zur Flora von Böhmen

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Ueber den Aufbau der Gattung Trifolium

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Microbial transformation of steroids

A systematic study of transformation reactions of Actinomycetes with respect to the progesterone molecule was undertaken. The results obtained, i.e. the types of transformation reactions in different actinomycete species, were evaluated from the point of view of taxonomy. The actinomycetes tested were divided according to the transformation types into three groups: (1) a group of species transforming progesterone in the 16α-position; (2) a group of species transforming progesterone in the β-position; (3) a group of species in which no capacity to transform progesterone into another steroid derivative was established. From the point of view of Actinomycete classification the transformation reactions on the steroid molecule fulfil all the requirements of taxonomic features of Actinomycetes. They appear to be specific properties, independent of strictly cultivation conditions and common to all the strains of individual actinomycete species tested.