EFFECT OF PHYSICAL AND CHEMICAL MUTAGENS ON VARIABILITY IN SPOROBOLOMYCES-ALBO-RUBESCENS VKM Y-2450

Lethal and mutagenic effects of UV light, N-nitroso-N-methylbiuret (NM B), and 1,4-bisdiazoacetylbutane (DAB) were studied in the exoglycan p roducer Sporobolomyces albo-rubescens VKM Y-2450. The spectrum of aris ing morphological mutants and the frequency of their occurrence were f ound to be different with different mutagens. NMB was highly efficient in the induction of petite mutants in Sp. albo-rubescens. DAB (0.1%) produced no lethal or mutagenic effect on the culture studied. Spontan eous and UV-induced morphological mutants were obtained that were capa ble, in contrast to the original culture, of glucogalactan synthesis. Morphotype Ill mutants induced by a single exposure of the original cu lture to a UV dose of 332.0 J/m(2) exhibited high genetic instability. Unlike UV light, DAB and NMB did not induce unstable mutations.