Cell Division Mutations in the Blue-Green Bacterium Agmenellum quadruplicatum Strain BG1: a Comparison of the Cell Wall

Abstract

The peptidoglycan from two types of filamentous cell division mutants of Agmenellum quadruplicatum strain BG1 has been compared to that of the parent organism. Small variations in the total peptidoglycan composition on a dry-weight basis were found in the mutants. The reduced level of peptidoglycan in the serpentine mutant is consistent with a general decrease in the ratio of surface area to volume as compared to the parent organism. The increased peptidoglycan content in the septate mutant confirms previous ultrastructural observations of the greatly enlarged peptidoglycan septum between adjacent cells. A comparison of peptidoglycan composition and cross-linking in the two types of filamentous mutants of A. quadruplicatum and in drug-induced phenocopies suggests that structural alterations of the peptidoglycan are not involved in the apparent impairments of cellular division. Furthermore, data concerning the relative susceptibilities of the parent and mutants to antibiotics indicate that neither mutant exhibits a gross alteration of permeability. 614

Differential effects of ethanol and hexanol on the Escherichia coli cell envelope

“…After growth for 2 h in medium supplemented with 0.51 M ethanol, only the un-cross-linked monomer was present. This form eluted with a Kay of 0.4, in good agreement with previous results (21,42). Material from cells grown in lower concentra-tions of ethanol contained intermediate levels of the monomer and dimer peaks.…”

“…Lysozyme digestion products of heat-activated cells were initially purified on an ECTEOLA-cellulose column (42). The purified digestion products (0.2 ml) were separated by using a Sephadex G-25 column (60 by 0.9 cm) as described previously (21). Fractions were analyzed for total reducing sugar by the method of Park and Johnson (32) as modified by Ghuysen et al (13) with N-acetylglucosamine as a standard.…”

Peptidoglycan synthesis and turnover in cell division mutants of Agmenellum

“…The cell walls of the blue-green bacteri.a are similar to those of gram-negative bacteria in both ultrastructure and composition (6,18,22). Although peptidoglycan synthesisand turnover has been described in both gram-positive and other gram-negative bacteria, no information has been reported dealing with these processes in this important group of prokaryotes.…”