Peptidoglycan synthesis during the cell cycle of Escherichia coli: composition and mode of insertion

Relationship between the acceptor/donor radioactivity ratio and cross-linking in bacterial peptidoglycan: application to surface synthesis during the division cycle

The relationship between the experimental measurement of the cross-linking of bacterial peptidoglycan and the mode of its insertion is analyzed. The cross-linking value, in practice and in theory, is independent of the pattern of strand insertion. Since the measure of the mode or pattern of insertion is the acceptor/donor radioactivity ratio (ADRR), no correction need be made for the ADRR. The measurement of cross-linking using radioactivity is independent of the labeling time, the specific activity of the label, and the mode of strand insertion. It is not concluded, however, that cross-linking does increase during the division cycle.

Isogenic variants of Escherichia coli with altered morphology have peptidoglycan with identical muropeptide composition

The peptidoglycan compositions of three isogenic morphological mutants of Escherichia coli were determined by high-pressure liquid chromatography analysis. The muropeptide compositions of the peptidoglycan of these mutants were the same, indicating that the shape of E. coli is not (solely) determined by the chemical composition of the peptidoglycan. Furthermore, it appeared that the muropeptide composition of the peptidoglycan was not affected by growth temperature.