[Identification with roseofungin of an antibiotic produced by Streptomyces roseoflavus strain A-23/791 and its undifferentiated variant].

Isolation, purification and chemical identification of an antibiotic produced by strain IMV A-23/791 of Streptomyces roseoflavus and its adifferentiated variant are described. The antibiotic inhibits the growth of many phytopathogenic fungi, dermatophytes and yeast-like fungi and is capable of stimulating the growth and development of plants. The antibiotic is effective in control of cucumber root rot under hydroponic cultivation conditions. It was shown that the adifferentiated proactinomycetous variant 4-76 was more productive than the initial strain A-23/791. The antibiotic isolated from the variant mycelium is more active. It was shown that the antibiotic can be isolated from the biomass of the adifferentiated variant with a more simple method in the authors' modification providing higher antibiotic yields and the use of lower amounts of the solvents. The UV, IR, mass and luminescence spectra and mobility in paper and thin-layer chromatography have shown the carbonyl-conjugated pentaene A-23/791 to be identical to roseofungin described earlier. Based on the data obtained strain A-23/791 should be classified with Streptomyces roseoflavus var, roseofungini Nikitina, 1968, a variant of Streptomyces roseoflavus Arai, 1951.