STRUCTURAL ELUCIDATION OF AN EXTRACELLULAR POLYSACCHARIDE PRODUCED BYLACTOBACILLUS-HELVETICUS

An extracellular polysaccharide produced by a strain of Lactobacillus helveticus isolated from cheese milk has been investigated. Sugar and methylation analysis together with H-1 and C-13 NMR spectroscopy revea led that the polysaccharide is composed of hexasaccharide repeating un its. The sequence of sugar residues was determined by use of two-dimen sional nuclear Overhauser effect spectroscopy and heteronuclear multip le-bond correlation experiments. The structure of the repeating unit o f, the exopolysaccharide from L. helveticus is as follows: [GRAPHICS] (C) 1996 Elsevier Science Ltd.