Structural Study of an Exocellular Polysaccharide of Bacillus circulans

Abstract

Bacillus circulans, a soil bacterium, produced an exocellular polysaccharide of high viscosity. On the basis of the results of methylation analysis, mild acid hydrolysis, and 1D and 2D ¹H-NMR spectroscopy, it was concluded that the polysaccharide has a basic repeating unit composed of β-L-rhamnopyanose, α-D-mannopyranose, α-D-galactopyranose, and α-D-glucopyranuronic acid with the following structure:[numerical formula]