1979 Volume 32 Issue 10 Pages 978-984
A screening method was established for selecting new specific inhibitors of bacterial cell wall peptidoglycan synthesis. In the primary test, culture broths of soil isolates were selected based on relative microbial activity. A culture, to be retained, must be active against Bacillus subtilis and lack activities against Acholeplasma laidlawii. In the secondary test, inhibitors of bacterial cell wall synthesis were identified by their ability to prevent the incorporation of meso-[3H]diaminopimelic acid but not to prevent the incorporation of L-[14C]leucine into the acidinsoluble macromolecular fraction of growing cells of Bacillus sp. ATCC 21206 (Dpm). As the tertiary test, inhibitors with molecular weights under 1, 000 were selected by passage through a Diaflo UM-2 membrane. By this screening procedure, six known antibiotics and one new one were picked out from ten thousand soil isolates.
