[Action of N-nitroso-N-methylbiuret on Penicillium nigricans Thom and the protective effect in UV irradiation].

N-Nitrozo-N-methylbiuret (NMB) in a concentration of 0.2% and exposition for 2,3,4 and 6 hours with the survival rate of the conidia of 4-25% induced slight morphological variation of the griseofulvin-producing organism and increased the variation rate with respect to the antibiotic production by 40-140%. Preliminary treatment of the conidia with NMB decreased the lethal effect of UV-rays approximately by 15-25 times. The protective range with respect to morphological variation was 10 times lower. With an increase in the toxicity of NMB its protective effect in irradiation with UV-light decreased.