STRUCTURAL STUDIES ON A CELL-WALL POLYSACCHARIDE PREPARATION OF LACTOCOCCUS-LACTIS SUBSPECIES CREMORIS H414

A cell wall polysaccharide preparation of Lactococcus lactis subsp. cremoris H414 was isolated by nitrous acid extraction, and purified by gel filtration and anion-exchange chromatography. Oligosaccharide fragments, obtained by partial acid hydrolysis or alkaline hydrolysis, were studied by means of monosaccharide analysis, methylation analysis, FAB-MS, EI-MS, and H-1 NMR spectroscopy. In addition H-1, C-13, and P-31 NMR spectroscopy, including two-dimensional homo- and heteronuclear measurements, were performed on the native polysaccharide. Combination of the various results demonstrated that in the polysaccharide preparation two repeating units with the structures [-->2)-alpha-L-Rhap-(1-->3)-alpha-D-Galp-(1-->](n) and [-->6)-[alpha-D-Galp-(1-->4)]-alpha-D-GalpNAc-(1-->3)-beta-D-GalpNAc-(1-->1)-Ribitol-(5-phosphate-->](m), respectively, can be recognized. So far, a covalent linkage between both polymers could not be confirmed nor be excluded.