[Action of hygromycin B on the producers of levorin and mycoheptin].

The effect of hygromycin B on survival and variation of the levorin and mycoheptinproducing organisms, i.e. Act levoris, strains 28 and PR-52/67 and streptoverticcium mycoheptincium, strain 44B/I was studied. When added to the agarized medium, hygromycin B had a lethal effect on the above strains. The lethal effect increased with an increase in the concentration from 2.5 80 Units/ml. High modification variation of the colony morphology was observed on media with hygromycin B. At the same time hygromycin B induced morphological and hygromycin-resistant mutants. The variation of the property of the antibiotic production in the above cultures increased under the effect of hygromycinB. The maximum rate of the plus variants was observed at high lethal effects of hygromycin B, when the survival rate of the spores was 10(-3) and 10(-4). An individual reaction of the cultures to hygromycin B was found. Formation of the mutation of resistance to the specific phage in the genome of strain PR of the levorin-producing organism increased its sensitivity to hygromycin and variation of the colony morphology and the property of the antibiotic production.