Structure of O-specific polysaccharide chains of lipopolysaccharides of Burkholderia (Pseudomonas) solanacearum ICMP 750, 8093, 8115, 7864, and 7945

Lipopolysaccharides were isolated from cells of phytopathogenic bacteria Burkholderia (Pseudomonas) solanacearum biovars I, II, and IV. O-Specific polysaccharides (O-PS4) were obtained by mild acid hydrolysis of the lipopolysaccharides followed by gel chromatography on Sephadex G-50. It was established by C-13-NMR spectroscopy that the O-PS of five strains studied are characterized by a linear or a branched structure. The linear structure is based on a tetrasaccharide containing three residues of L-rhamnose and one residue of N-acetylglucosamine, The strains differ in the configuration of the glycosidic linkage of N-acetylglucosamine (alpha or beta) and in the type of the connection between N-acetylglucosamine and the neighboring rhamnose residue (1-->2 or 1-->3). The branched structure is a xylosylated form of the linear structure and, therefore, consists of pentasaccharide repeating units. The strains studied may be characterized by more than one type of the O-PS structure including both linear and branched repeating units. No correlation was found between the structure of O-PS and either the belonging of the strain to a certain biovar or its specificity to the host-plant.