Relative Contribution of the Cell Wall, Cytoplasmic Membrane, and Cytoplasm to the Gram-Positive Characteristic of Bacillus megaterium

Abstract

Angeles), AND THOMAS CROMWELL. Relative contribution of the cell wall, cytoplasmic membrane, and cytoplasm to the gram-positive characteristic of Bacillus megaterium. J. Bacteriol. 90:643-647. 1965.-A comparison of the roles of the cell wall, cytoplasmic membrane, and cytoplasmic components revealed that the intact cell wall was the dominant contributor to the gram-positive state. Protoplasts of Bacillus megaterium were confirmed as being gram-negative, as reported by Gerhardt et al. The "gram-positive protoplast" report of Amano et al. was shown to be a laboratory-produced artifact, resulting from the comparison of smears made from saline suspensions of Escherichia coli cells with smears made from formalin-sucrose suspensions of B. megaterium protoplasts.

Analysis of the Mechanism of Gram Differentiation by Use of a Filter-Paper Chromatographic Technique

“…That the cell wall is the principal of the two generally accepted permeation barriers (cytoplasmic membrane and cell wall) was shown by comparisons of the gram-positivity of intact cells, protoplasts, and ruptured protoplasts. In such comparisons, it was found that the cytoplasmic membrane and cytoplasm components were responsible for only a very small fraction of the total resistance to decolorization of gram-positive organisms (Bartholomew and Cromwell, 1965). That the cell wall is primarily responsible for Gram differentiation has been the conclusion of numerous researchers (Burke and Barnes, 1929;Mittwer et al, 1950;Bartholomew and Mittwer, 1951;Wensinck and Boeve', 1957;Salton, 1963;Scherrer, 1963).…”