Variability of peptidoglycan surface density in Escherichia coli

Murein synthesis in Escherichia coli can be partially inhibited by D-methionine without concomitant alterations in growth and morphology. D-Methionine-treated cultures grow steadily for an indefinite time, therefore murein surface density should be reduced. Determination of this parameter in control and D-methionine-treated cells showed a severe reduction in the latter. Murein surface density increases drastically in resting cells, irrespective of the presence of D-methionine. Mutants in ponB are hypersensitive to D-methionine. Analysis of ponB strains revealed an important reduction in murein surface density. An approximately two-fold reduction in average surface density is apparently compatible with normal growth and division.