| Abstract: | The cell‐surface carbohydrates of Porphyromonas gingivalis strain ATCC 53978 were isolated and partially characterized. Three separate polysaccharides were found to be present: an extracellular polysaccharide, capsular polysaccharide and lipopolysaccharide. The capsular polysaccharide, which had peculiar, gel‐like viscoelastic properties, was found to be comprised of mannuronic acid, glucuronic acid, galacturonic acid, galactose, and 2‐acetamido‐2‐deoxy‐ d ‐glucose in relative molar ratios of 0.6:0.9:0.5:0.5:1.0, respectively. The extracellular polysaccharide was found to contain mannose, rhamnose, glucose, galactose, and 2‐acetamido‐2‐deoxy‐ d ‐glucose in relative molar ratios of 13.5:1.4:1.0:2.0:1.0, respectively. The lipopolysaccharide was found to contain an O‐antigen with a regular tetrasaccharide repeat unit comprised of 4‐linked α‐ l ‐rhamnopyranosyl, 6‐linked α‐ d ‐glucopyranosyl, 3‐linked α‐ d ‐galactopyranosyl, and 4‐linked 2‐acetamido‐2‐deoxy‐β‐ d ‐glucopyranosyl residues in equimolar proportions. |
