title: Lipophilic O-antigens in Rhodospirillum tenue.
abstract: Lipopolysaccharides of eight wild-type strains of the phototrophic bacterium Rhodospirillum tenue have been analyzed. All of the lipopolysaccharides are highly lipophilic. The compositions of preparations obtained by the phenol-water or by the phenol-chloroform-petroleum ether procedure are very similar. The polysaccharide moiety, obtained by mild acid hydrolysis of lipopolysaccharide, consists mainly of aldoheptoses: L-glycero-D-mannoheptose is present in all strains, whereas D-glycero-D-mannoheptose is an additional constituent in some strains. Galactosaminuronic acid and two unknown ninhydrin-positive components were detected in the lipopolysaccharides of six strains. Spermidine and putrescine are present in large amounts in a salt-like linkage in the lipopolysaccharides from three strains. 2-Keto-3-deoxyoctonate forms the linkage between the polysaccharide moiety and lipid A. The lipid A fraction contains all the glucosamine and all the D-arabinose present in the lipopolysaccharide. D-Arabinose is an invariable constituent of the lipid A from the Rhodopseudomonas tenue lipopolysaccharides investigated. The principal fatty acids are beta-hydroxycapric, myristic, and palmitic acids. The isolated R. tenue lipopolysaccharides (O-antigens) react with rabbit antisera prepared against homologous cells. The titers in passive hemagglutination are low, similar to those found with enterobacterial R-lipopolysaccharides. R. tenue O-antigens containing only L-glycero-D-mannoheptose and those containing both the L- and D-epimers of glycero-D-mannoheptose could not be differentiated by serological means.
mesh_terms: D000588:Amines / Q000032:analysis; D000818:Animals; D000942:Antigens, Bacterial / Q000032:analysis*; D002241:Carbohydrates / Q000032:analysis; D003429:Cross Reactions; D006384:Hemagglutination; D008050:Lipid A / Q000032:analysis; D008070:Lipopolysaccharides / Q000032:analysis / Q000276:immunology / Q000302:isolation & purification; D019081:O Antigens; D011817:Rabbits; D012246:Rhodospirillum / Q000145:classification / Q000276:immunology*
chemical_list: D000588:Amines; D000942:Antigens, Bacterial; D002241:Carbohydrates; D008050:Lipid A; D008070:Lipopolysaccharides; D019081:O Antigens