STRUCTURE OF A GALACTAN FROM CELL-WALLS OF BIFIDOBACTERIUM-CATENULATUM YIT4016

A structural study was carried out on a galactose-rich polysaccharide fraction isolated from cell walls of Bifidobacterium catenulatum YIT40 16 after N-acetylmuramidase digestion. The polysaccharide contained ga lactose and glucosamine in a molar ratio of 16.9:1.0. Data obtained by C-13 NMR spectroscopy showed that the backbone chain of this polysacc haride is composed of galactofuranose residues, while the branches con sist of galactopyranosyl residues. Furthermore, the data obtained from NaIO4 oxidation, partial methanolysis and methylation analysis indica ted that this polysaccharide consists of a trisaccharide repeating uni t having the following structure: [-->6)-beta-D-Galf-(1-->5)-beta-D-Ga lf(1-->](n) 6 up arrow 1 alpha-D-Galp