The chemical composition of the cell envelope of Streptobacillus moniliformis

The chemical composition of the cell envelope of the bacillary form of Streptobacillus moniliformis was investigated to determine if there were any unusual features which might account for the ability of this organism to produce L forms spontaneously. A procedure was developed for the preparation of particles of the cell envelope using sonic oscillation to disrupt the cells. Particles of the cell envelope of E. coli B prepared by this method were comparable to those preparations obtained by other methods. The percentages of the major chemical components of the cell envelope of S. moniliformis were 64% protein, 28% lipid, and 6% carbohydrate. Cell envelope preparations made from E. coli B contained 66% protein, 18% lipid, and 10% carbohydrate. All common amino acids were present in hydrolysates of the cell envelope of S. moniliformis with the exception of cysteine. The monosaccharides detected in hydrolysates of the cell envelope of S. moniliformis were glucose, galactose, heptose, glucosamine, and muramic acid. The amounts of glucosamine and muramic acid (and presumably therefore mucopeptide) present in the cell envelope of S. moniliformis were much less than those amounts detected in the cell envelope of E. coli B. It is suggested that the low content of mucopeptide may be related to the ability of S. moniliformis to produce L forms spontaneously.