Adaptation of a stable L form of Bacillus subtilis to minimal salts medium without osmotic stabilizers

Abstract

An L form isolated from B. subtilis 168 was adapted to growth in a 340 mOsm minimal salts medium without the addition of osmotically protective solutes. This L form had no chemically detectable peptidoglycan residues on its surface, but 0.8% of the dry weight of washed membranes was hexosamine. The osmotic stability and susceptibility to bacitracin and vancomycin of the L form adapted to growth in 340 mOsm osmotically unprotected medium was twice that of the L form grown in 2,680 mOsm medium supplemented with 1.2 M NaCl.