PARTIAL CHARACTERIZATION OF THE LIPOPOLYSACCHARIDES OF PEANUT SPECIFIC BRADYRHIZOBIUM STRAINS

Hexoses, heptose, hexuronic acids, 2-keto-3-deoxyoctonic acid (Kdo) co ntents of the lipopolysaccharides (LPS) isolated from peanut (A. hypog aea) specific Bradyrhisobium strains NC 92, IGR 92, IGR 40 and IGR 6 w ere found to vary considerably. Sodium dodecyl sulphate polyacrylamide gel electrophoresis showed a heterogenous LPS population and distinct heterogenity was observed in NC and IGR strains. Sepharose gel filtra tion chromatography removed the hexose contaminants from NC 92 LPS. Po lysaccharides obtained by mild acid hydrolysis of Sepharose purified N C 92 LPS were further purified on Sephadex G-50 gel filtration. Immuno blot analysis indicated cross reactivity amongst the peanut specific B radyrhisobium strains but not with B. juponicum(SB 16). antibodies rai sed against native NC 92 LPS showed higher binding towards the Sephade x purified polysaccharides suggesting the antigenic property of polysa ccharide moiety in LPS molecule.