Structure of the capsular polysaccharide and the O-side-chain of the lipopolysaccharide from Acetobacter methanolicus MB 70, and of oligosaccharides resulting from their degradation by the bacteriophage Acm6

Abstract

Acetobacter methanolicus MB 70 was shown to be related to the type strain of this species MB 58/4 (IMET 10945)having the same galactan → 2)-β- d-Gal f-(1 → 3)-β- d-Gal p-(1 → as the capsular polysaccharide (CPS) and the O-side-chain of the lipopolysaccharide (LPS). Additionally, a glucan built up of the disaccharide repeating unit → 6)α- d-Glc p-(1 → 2)-α- d-Glc p-(1 → was identified in strain MB 70. In the CPS, the polymers were present in the ratio ∼ 1:1, whereas the glucan preponderated in the LPS. Bacteriophage Acm6 specific to A. methanolicus MB 70 hydrolysed selectively the glucan component of both CPS and LPS. Structural elucidation of the resulting oligosaccharides led to the identification of the phage-associated depolymerase as an endo-α-(1 → 6)- d-glucopyranoside hydrolase.