Inhibition of de novo fatty acid synthesis by the antibiotic cerulenin in Bacillus subtilis: effects on citrate-Mg2+ transport and synthesis of macromolecules

Abstract

Inhibition of de novo fatty acid biosynthesis by the antibiotic cerulenin in Bacillus subtilis stopped de novo synthesis of neutral lipids and phospholipids. The bacteria ceased growing but remained completely viable. Addition of 12-methyltetradecanoic acid and palmitic acid to the culture medium of cerulenin-treated cells restored growth of the bacteria, albeit at a reduced rate. Although the de novo synthesis of all lipid components of the membrane was blocked, citrate-Mg(2+) transport activity remained inducible, and induced cells did not lose this transport activity when treated with cerulenin. Shortly after the addition of cerulenin, the rate of ribonucleic acid synthesis dropped rapidly and was followed by a slower decrease in the rate of protein synthesis. The rate of deoxyribonucleic acid synthesis remained almost unaffected. The rapid decrease of ribonucleic acid synthesis in cerulenin-treated cells might be due to the inhibition of de novo fatty acid biosynthesis or it might be due to a secondary effect of cerulenin in B. subtilis cells.