ISSN:
1432-072X
Keywords:
Lipopolysaccharides
;
O-Antigens
;
Chemical Composition
;
Serology
;
Rhodopseudomonas viridis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The present paper deals with the isolation, and chemical and serological characterization of the O-antigens (lipopolysaccharides, LPS) of the photosynthetic gram-negative bacterium Rhodopseudomonas viridis. The LPS are extractable with hot phenol/water, but unlike the phenol-soluble LPS of the closely related species Rhodopseudomonas palustris, the R. viridis O-antigens are preferentially extracted into the water phase. A mixture of phenol/chloroform/petroleum ether (PCP-method) does not extract the R. viridis LPS. All R. viridis LPS investigated belong to the same chemotype, the polysaccharide moiety of these O-antigens being composed of 3-O-methyl-l-xylose, 3-O-methyl-d-mannose, d-mannose, d-galactose, d-glucose, in addition to 2-keto-3-deoxyoctonate (KDO), glucosamine, 6-deoxyglucosamine (quinovosamine) and galactosamine uronic acid. The R. viridis O-antigens are clearly distinguishable from the l-glycero-d-mannoheptose containing O-antigens of R. palustris by the lack of this sugar (and of any other heptose) in the R. viridis LPS. The lipid moiety (lipid A) of the R. viridis O-antigen can be split off from the LPS by mild acid hydrolysis. Like lipid A from R. palustris, it differs remarkably from the well known lipid A of Enterobacteriaceae, in that d-glucosamine is replaced by a recently identified 2.3-diamino-2.3-dideoxyhexose in the R. viridis and R. palustris lipid A. Unlike enteric lipid A the R. viridis lipid A is phosphate-free and includes as the only fatty acid β-C14OH which is exclusively amide-linked. All R. viridis strains belong to the same serotype so far as investigated, as shown by passive hemagglutination with the isolated O-antigens and rabbit antisera against heat-killed cells.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00455941
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