A new polymer of 8,9-Di-O-Glucosylated 2-keto-3-deoxy-D-glycero-D-galacto-nonulosonic acid from a cell wall of Brevibacterium casei ACM Ac-2114T

A polysaccharide containing the residues of 2-keto-3-deoxy-D-glycero-D-galacto-nonulosonic acid (Kdn) was found in the cell wall of the Brevibacterium casei strain AEI Ac-2114T . The polymer structure was elucidated by analyzing one-dimensional spectra of 1H and 13C NMR and bidimentional experiments 1H/13C-COSY, TOCSY, 1H/13C-gHSQC, and 1H/13C-gHMBC. The polymer is built up of the 2--> 4-linked Kdn residues substituted by beta-D-Glcp residues at 8- and 9-hydroxyls; such a polymer with disubstituted Kdn residues was found for the first time. A glycosylated teichoic acid of the 1,3-poly(glycerophosphate) type was also identified among other anionic polymers of cell wall.