[Natural and induced variability of pathogen, producing antifungal antibiotic, imbrimycin]

Natural and induced variation of Streptomyces imbricatus LIA 0112, an organism producing imbricin, a nonpolyene antifungal antibiotic, was studied. The culture was shown to be homogeneous by the morphological and cultural properties and consisted of one (rarely two) morphological type depending on the medium composition. The effect of some mutagens such as UV light, N-nitroso-N-methyl biuret in a concentration of 0.05 per cent and 1,4-bisdiazoacetyl butane in a concentration of 0.1 per cent on the actinomycete culture was investigated. It was found that the imbricin-producing culture was stable to the effect of both the physical and chemical mutagens. As a result of multistep selection of the actinomycete culture its productivity increased by 22 per cent.