Extracellular polysaccharides produced by acetic acid bacteria. Part II. Structure of an acidic polysaccharide from Acetobacter sp. NBI 1022.

Abstract

An acetic acid bacterium which produces a new type of extracellular soluble polysaccharide was isolated from vinegar mash. The isolated strain, NBI 1022, was tentatively identified as Acetobacter aceti subsp. xylinum. The polysaccharide, named AM-2, was composed of d-glucose, l-rhamnose, d-mannose, d-glucuronic acid, and O-acetyl in a molar ratio of approximately 4:1:1:1:1. From the results of methylation, Smith degradation, and partial acid hydrolysis of the polysaccharide and its derivatives, the polysaccharide AM-2 may have a branched structure containing a backbone chain of β-(1→4)-linked d-glucose residues and a side chain shown as l-rhamnosyl-(1 → 6)-β-d-glucosyl-(1 → 6)-d-glucosyl-(1 → 4)-d-glucuronosyl-(1 → 2)-d-mannose.