Abstract
The antibiotic action of poly ketoacidomycin (PKAM) on Bacillus subtilis was examined. PKAM stimulated the turnover of phosphatidyl glycerol (PG) to cardiolipin (DPG) and reduced the amounts of the normal fatty acids (nFAs) C-14 and C-16 and anteiso (a) C-17. Addition of bacterial PG to cultures treated with PKAM reduced the effect of the antibiotic.
The foregoing changes in lipid composition were associate d with changes in cell permeability . Loss of cellular valine, norvaline and phosphates was observed and a significant decrease in the cellular concentration of Na+ and K+ ions was noted when the test organism was incubate d with PKAM for periods up to 15 minutes. Longer incubation of the bacteria with the antibiotic caused an appreciable increase in RN A content of the cells and a reduction in the DNA and protein content. Polyketoacidomycin (PKAM), first isolated b y SHIMI et al., 1) possesses substantial anti-microbial activity against gram-positive bacteria as well as some gram-negative bacteria. The acid hydrolysate of the antibiotic contains glucose, alanine, and acetone, as well as pyruvic, glyoxylic, α-ketoglutaric, α-ketobutyric and acetoacetic acids.
