Action of mycosubtilin, an antifungal antibiotic of Bacillus subtilis, on the cell membrane of Saccharomyces cerevisiae.

Mycosubtilin, an antibiotic of the iturin group, inhibits the growth of Saccharomyces cerevisiae by a fungicidal action. Increasing concentrations of mycosubtilin decrease the incorporation of radioactive precursors into proteins, RNA and polysaccharides without specificity. Yeast spheroplasts are lysed by mycosubtilin. Its action on the cytoplasmic membrane induces important modifications of the membrane permeability: nucleotides, proteins and lipids are released from the cells. These releases increase with increasing concentrations of mycosubtilin.