Structure of the polysaccharides from the lipopolysaccharide of Azospirillum brasilense Jm125A2

•The O-specific polysaccharide (OPS) from A. brasilense Jm125A2 was investigated.•OPS preparation contains two different polysaccharide chains.•Repeating units of both O-polysaccharides were established.

Two polysaccharides were obtained by mild acid degradation of the lipopolysaccharide of associative nitrogen-fixing bacteria Azospirillum brasilense Jm125A2 isolated from the rhizosphere of a pearl millet. The following structures of the polysaccharides were established by sugar and methylation analyses, Smith degradation, and 1H and 13C NMR spectroscopy:Figure optionsDownload full-size imageDownload as PowerPoint slideStructure 1 has been reported earlier for a polysaccharide from A. brasilense S17 (Fedonenko YP, Konnova ON, Zdorovenko EL, Konnova SA, Zatonsky GV, Shaskov AS, Ignatov VV, Knirel YA. Carbohydr Res 2008;343:810–6), whereas to our knowledge structure 2 has not been hitherto found in bacterial polysaccharides.

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