Bacillus licheniformis peptidoglycan characterization by CZE–MS: Assessment with the benchmark RP‐HPLC‐MS method

Abstract

Peptidoglycan or murein is an essential polymer found in bacterial cell wall. It is a dynamic structure that is continuously remodeled or modified during bacterial cell growth or in presence of cell wall stresses. These modifications are still poorly understood mainly due to the peptidoglycan, which is rather non‐soluble, and the difficulties to separate the hydrophilic glycopeptides (muropeptides) by reversed phase liquid chromatography, generated by the enzymatic digestion using mutanolysin, an N‐acetyl‐muramidase, cleaving the β1→4 bound between N‐acetylglucosamine and N‐acetylmuramic acid. Here, we report the use of CZE–MS for an easy and fast screening of muropeptides generated by the action of muramidase on the Bacillus licheniformis cell wall. Electron transfer and CID–MS were also used to unambiguously identify and localize the presence or the absence of amidation and acetylation moieties on muropeptide variants. The reference method to analyse muropeptides by reversed phase chromatography was also tested and the advantages and disadvantages of both methods were evaluated.

Deletion of pbpC Enhances Bacterial Pathogenicity on Tomato by Affecting Biofilm Formation, Exopolysaccharides Production, and Exoenzyme Activities in Clavibacter michiganensis

“…The thinner cell wall of the △ pbpC mutants, with a distorted peptidoglycan layer, led to the reduction in peptidoglycan cross-links. The structural variation in the pbpC mutants resembling a “ridge and groove” surface, compared with the relatively standard flat surface in wild-type and complementation strains, as observed by atomic force microscopy, may have affected host plant recognition [ 62 ]. Nevertheless, the reduction in cell wall peptidoglycan in the △ pbpC mutants (data not shown) may also have led to the interference of host plant recognition.…”