Lipopolysaccharides of Legionella erythra and Legionella oakridgensis
The chemical composition of lipopolysaccharides from Legionella erythra and Legionella oakridgensis was analysed. Sodium dodecyl sulfate polyacrylamide gel electrophoresis showed both lipopolysaccharides to have a smooth-type character. The polysaccharide part of both lipopolysaccharides contained D-mannose, D-glucose, D-glycero-D-mannoheptose, L-glycero-D-manno-heptose, 2-keto-3-deoxyoctonic acid, L-fucosamine, D-glucosamine, and glucosamine phosphate. In addition, L-rhamnose, glycerol phosphate, and glucose phosphate were identified in the polysaccharide part of L. erythra lipopolysaccharide. The main sugar identified in the lipid A part of both lipopolysaccharides, 2,3-diamino-2,3-dideoxy-D-glucose, was found to be substituted with a complex fatty acid composition including at least 16 different amide-linked 3-hydroxy fatty acids. Both lipopolysaccharides contained nonhydroxy fatty acids and the uncommon 27-oxo-octacosanoic acid, 29-oxotriacontanoic acid, and 27-hydroxyoctacosanoic acid. The lipopolysaccharide of L. oakridgensis also contained 29-hydroxytriacontanoic acid. The dioic long-chain acids heptacosane-1,27-dioic acid and nonacosane-1,29-dioic acid were only present in the lipopolysaccharide of L. erythra.Key words: taxonomy, long-chain fatty acids, chemical analysis, 2,3-diamino-2,3-dideoxy-D-glucose.