The chemical composition of the soluble and insoluble fractions of the bacterial cell

Abstract

The soluble and insoluble fractions of 8 spp. of bacteria were separated by centrifuging the material obtained after disintegrating the cells by shaking with glass beads. The insoluble material, believed to be mainly derived from the cell wall, accounted in most cases for about half the dry wt. of the cell. Estimations were performed on both fractions for ash, N, P, hexose, pentose, deoxypentose and nucleic acid, the last being detd. spectroscopic-ally. Wide variations were found among different organisms but certain regularities were observed. Notably, nucleic acid was confined to the soluble fraction, which was also much richer in P, pentose and deoxypentose. Concepts of the bacterial cell wall are discussed in the light of these findings.