Structure of the exocellular D-glucan produced by Neisseria polysaccharea

Neisseria polysaccharea (LNP 462, NCTC 11858), proposed as a prototype strain constituting a new taxon in the genus Neisseria, produces copious amounts of polysaccharide when grown on agar containing 1-5% sucrose. Plate-grown cells produced an exocellular polysaccharide which was composed of D-glucose, had [alpha]D +222 degrees (water), and was shown from composition, specific optical rotation, methylation, enzymic hydrolysis, and 13C nuclear magnetic resonance studies to have an amylopectinlike structure containing mainly 1,4-linked alpha-D-glucopyranosyl residues, but also containing ca. 6% 4,6-di-O-substituted alpha-D-glucopyranosyl branch points.