Bromide and thiocyanate have been shown to be effective inhibitors of the chlorination process leading to chlortetracycline formation by certain strains of Streptomyces aureofaciens Duggar (Gourevitch et al., 1955; Doerschuk, et at., 1956). Sekizawa (1955) reported thiourea, 2-thiouracil, 2-mercaptobenzothiazole, and thioglycolic-f3-aminonaphthalide (thionalide) to inhibit chlorination by this ...

2-Chloroethylphosphonic acid (CEPA) affected both the growth of and antibiotic production in Streptomyces aureofaciens, S. griseus, S. antibioticus, and Penicillium citrinum. Streptomyces strains seemed to be more sensitive to the presence of CEPA in the medium than did the fungus. A decrease in both growth and antibiotic production was observed with a concomitant increase in the concentration ...

During the sudden decrease in RNA synthesis in Streptomyces aureofaciens, i.e. around the 6th hour of cultivation, synthesis of adenosine and guanosine tetraphosphates and pentaphosphates begins. The synthesis of these nucleotides is highest during the onset of chlortetracycline production, around the 20th hour of cultivation and continues. During this phase of growth of S. aureofaciens, RNA an...

Bromide and thiocyanate have been shown to be effective inhibitors of the chlorination process leading to chlortetracycline formation by certain strains of Streptomyces aureofaciens Duggar (Gourevitch et al., 1955; Doerschuk, et at., 1956). Sekizawa (1955) reported thiourea, 2-thiouracil, 2-mercaptobenzothiazole, and thioglycolic-f3-aminonaphthalide (thionalide) to inhibit chlorination by this ...

glucose 6-phosphate dehydrogenase (g6pd) was purified from streptomyces aureofaciens and inactivated with butanedione and diethylpyrocarbonate. incubation of the enzyme with butanedione resulted in a rapid activity loss (80%) within 5 min, followed by a slow phase using a molar ratio to enzyme concentration of 100. fluorescence studies showed a conformational change in the butanedione-modified ...

The growth phases of five cultures of antibiotic producing Streptomyces isolated from western region, Saudi Arabia were studied spe. cial reference to their potentiality to excrete antibiotics. It was found that these organisms grew exponentially during the first 4 to 7 days of incubation. The highest specific growth "rate was observed in the case of Streptomyces MY18 being 0.48 day-l (1.44 day...

interaction of glucose 6-phosphate dehydrogenase from s. aureofaciens with nad+, nadp+and glucose 6-phosphate were investigated using different fluorescent probes. binding of nad+, nadp+and s-nadph to the native enzyme quenched intrinsic protein fluorescence by 100%, 10% and 21%,respectively, from which kd values of nad+ (6.5 mm), nadp+ (92.0 μm) and s-nadph (122.0 μm)were calculated. binding o...

The addition of serine to minimal medium inhibited the growth of Streptomyces aureofaciens and Streptomyces rimosus. Both the outgrowth of spores and the growth of vegetative cells were inhibited by l-serine. This effect was independent of the carbon source used. In rich nutrient medium, however, the serine effect was not observed. The presence of glycine and methionine in minimal medium revers...