The Composition of the Spore Wall and the Wall of Vegetative Cells of Bacillus subtilis

Abstract

The spore wall of Bacillus subtilis is composed largely of structural protein, in contrast to the peptide + amino sugar + sugar complex of the wall of vegetative cells. Alanine, glutamic acid, ae-diaminopimelic acid, glucosamine, muramic acid, glucose, ribitol compounds and O-ester groups are the principal constituents of the vegetative cell walls. All of the compounds characteristic of the peptide + amino sugar + sugar complex have been detected in the spore wall preparations but they account only for a minor part of the spore wall. The walls of the vegetative bacteria have a high phosphorus content and contain appreciable amounts of a ribitol phosphate polymer. Spore walls and vegetative cell walls differ also in the nature of their N-terminal amino acids; glycine is the principal N-terminal amino acid of the spore wall protein whereas alanine is the main amino acid found in the wall of vegetative cells.