Characterization of O-Antigens from Different Strains of Pseudomonas syringae pv. tabaci

G. M. Zdorovenko,^1,2 L. P. Solyanik,¹ L. M. Yakovleva,¹ and N. A. Paramonov³

¹Zabolotnyi Institute of Microbiology and Virology, National Academy of Sciences of Ukraine, ul. Zabolotnogo 154, Kiev, 252143 Ukraine; fax: (044) 266-23-79.

²To whom correspondence should be addressed.

³Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Leninskii pr. 47, Moscow, 117913 Russia; fax: (7-095) 135-53-28.

Submitted June 21, 1995; revision submitted July 17, 1996.

O-Antigens (lipopolysaccharides, LPS) were isolated by NaCl extraction from microbial biomass of Pseudomonas syringae pv. tabaci and purified by ultracentrifugation. Individual structural components of the LPS macromolecule (O-specific polysaccharide (O-PS), core oligosaccharide, and lipid A) were obtained and characterized. Fatty acids 3-OH-C_10:0, C_12:0, 2-OH-C_12:0, 3-OH-C_12:0, C_16:1, C_16:0, C_18:1, and C_18:0 were identified in the lipid A composition. Glucosamine, ethanolamine, and phosphoethanolamine were found in the hydrophilic part of the lipid A macromolecule in all strains tested. Lipid A preparations contained phosphorus and amino acids. Rhamnose, glucose, glucosamine, 2-keto-3-deoxyoctulosonic acid, heptose, alanine, and phosphorus were identified as the main core components. The strains differed in O-PS structure. We describe the O-chain of LPS in strain P-28. It contains repeating units of the following structure: (see full article for figure). The O-PS structures of LPS from strains P-28 and 225 are identical, however, they differ substantially from that of strain 223. Both structures from strains 223 and 225 were reported previously. Antibodies to antigenic epitopes of O-PS, core, and lipid A were revealed in O-serum against the whole bacterial cells. Correlation of O-PS structure with the serological grouping of strains was observed.

KEY WORDS: O-antigen, lipopolysaccharide, lipid A, core, O-specific polysaccharide, composition and structure of lipopolysaccharide, Pseudomonas syringae.

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