THE STRUCTURE OF THE O-SPECIFIC POLYSACCHARIDE FROM THIOBACILLUS-FERROOXIDANS IFO-14262

Lipopolysaccharide (LPS) was isolated from Thiobacillus ferrooxidans I FO 14262 by the hot phenol-water extraction procedure. The O-specific polysaccharide, liberated from LPS by mild acetic acid hydrolysis, had a branched pentasaccharide repeating-unit composed of D-glucose, L-rh amnose, D-rhamnose, and 3-O-methyl-L-rhamnose in approximate molar rat ios of 2:1:1:1. On the basis of methylation analysis, H-1 and C-13 NMR spectroscopy, including 2D shift-correlated (COSY) and 1D NOE spectro scopy, the structure for the repeating unit of the O-specific polysacc haride was established, and the assumed biological repeating unit indi cated.