Analysis of the peptidoglycan structure of Bacillus subtilis endospores

Peptidoglycans was prepared from purified Bacillus subtilis spores of wild-type and several mutant strains. Reversed-phase high-pressure liquid chromatography, amino acid and amino sugar analysis, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry were utilized to study the peptidoglycan structure in wild-type and mutant spores. In wild-type spores, 50% of the muramic acid was converted to lactam. The remaining 25% had tetrapeptide or tripeptide side chains. Spores of a dacB mutant lacked the sporulation-specific penicillin-binding protein. Only 46% of the muramic acid in these spores was in lactam form.