Oligosaccharide beta-glucans with unusual linkages from Sarcina ventriculi.

The structure of a family of unusual glucans from Sarcina ventriculi has been characterized by NMR spectroscopy, methylation analysis, and mass spectrometry. One is a trisaccharide containing a beta-(1-->3) and a beta-(1-->4)-linkage. The other is a hexasaccharide that is simply a 1,4-linkage dimer of the trisaccharide unit. This is the first report of beta-glucan biosynthesis in a Gram-positive organism. Their occurrence in these organisms supports an even more general link between their synthesis and the adaptability of bacteria.