Structure determination of the exopolysaccharide produced by Lactobacillus rhamnosus strains RW-9595M and R (original) (raw)

2002, Biochemical Journal

Centre de recherche et de de! veloppement sur les aliments, Agriculture et Agroalimentaire Canada, 3600 boulevard Casavant Ouest, Saint-Hyacinthe, Que! bec, Canada J2S 8E3 Exopolysaccharides (EPSs) were isolated and purified from Lactobacillus rhamnosus strains RW-9595M, which has been shown to possess cytokine-stimulating activity, and R grown under various fermentation conditions (carbon source, incubation temperature and duration). Identical "H NMR spectra were obtained in all cases. Molecular masses were determined by gel permeation chromatography. The primary structure was elucidated using chemical and spectroscopic techniques. Organic acid, monosaccharide and absolute configuration analyses gave the following composition : pyruvate, 1 ; -glucose, 2 ; -galactose, 1 ; and -rhamnose, 4. Methylation analysis indicated the presence of three residues of 3-linked rhamnose, and one residue each of 2,3-linked rhamnose, 2-linked glucose, 3-linked glucose and 4,6-linked galactose. The EPS was submitted to periodate oxidation followed by borohydride reduction. Monosaccharide