Additional antibiotic inhibitors of peptidoglycan synthesis

Diumycin, janiemycin, nisin, and subtilin inhibited peptidoglycan synthesis catalyzed by particulate enzyme systems from Bacillus stearothermophilus and Escherichia coli. All of these, except for nisin, also induced accumulation of the lipid intermediate in peptidoglycan synthesis. Concentrations required for 50% inhibition of peptidoglycan synthesis were less than 0.1 mug/ml for diumycin and in the range of 10 to 100 mug/ml for janiemycin, nisin, and subtilin in both organisms. The discrepancy between the extremely low concentration of diumycin required to inhibit the in vitro system from E. coli and the much higher concentration required to inhibit growth of the organism is noteworthy.