Cell Walls of a Teichoic Acid Deficient Mutant of <i>Bacillus subtilis</i>

Abstract

The Cbl‐1 mutant of Bacillus subtilis 168 WT is the result of a spontaneous mutation pressenting a pleiotropic character. In this paper, the results of the morphological and chemical analyses of the cell walls isolated from bothe strains are compared. Whenm either trhe whole cells or the isolated cell walls of both strains were fixed with osmium tetroxide, the examination by electron microscopy showed extensive morphological differences in structure due to the partial destruction of the mutant cell walls. The chemical investigaions performed on the isolated cell walls revealed surprising differences in chemical structure. In the cells walls of the mutant, teichoic acid was completely missing and was replaced by protein. A major protein‐containing fraction accounting for about 50% of the material soulubilozed by autolysis of the mutant cell walls was isolated. Polyacrylamide gel electrophoresis showed that this fraction was composed mainly of a single protein of high molecular weight. When denatured by soduim dodecylsufate treactment in the pressence of β‐mercaptoethanol, the protein yielded by gel electrophoresis two major bands with molecular weights of approximately 105000 and 155000, repectively. The molecular weight of the Cbl‐1 ‐cell wall protein determined by high speex sedimentation equilibrium was 255600.