Antibiotics produced by Streptomyces olivaceus 142. I. Characterization of the FPG mutant and conditions of production of antibiotic WR 142-FPG.

By treating the Streptomyces olivaceus 142 strain simultaneously with ethyleneimine and UV radiation, the FPG mutant was isolated, which was characterized by the fact that in submerged cultures it produces a cytotoxic substance for fibroblasts and tumor cells and inhibits growth of pathogenic fungi. The mutant differs from other strains not only in having a different spectrum of antimicrobial activity, but also by taxonomic properties such as color of the aerial mycelium, liquefaction of gelatin, growth on cellulose, production of ammonia and nitrate reduction. An optimal culture medium and conditions of biosynthesis of the antibiotic in submerged cultures on the shaking machine and in 20-liter fermentation tanks were elaborated. The active substance was designated by the symbol WR 142-FPG.