CHARACTERIZATION OF 2 LIPOPOLYSACCHARIDE TYPES ISOLATED FROM RHIZOBIUM-GALEGAE

Lipopolysaccharides (LPS) of Rhizobium galegae, a symbiotically nitrog en-fixing species of root-nodule bacteria, were isolated by the phenol -water method from strain HAMBI 1461, the LPS of which resembled enter obacterial smooth type LPS, and from strains HAMBI 1174 and HAMBI 1208 , the LPSs of which resembled rough type LPS. The results of PAGE anal ysis of LPSs, Bio-Gel P2 gel filtration of polysaccharide fractions an d the presence of deoxysugars and 4-O-methyl-deoxysugar both in the ro ugh and smooth LPSs suggested that rough LPS contained a short O-antig enic polysaccharide for which we propose the name short O-chain LPS. A ccordingly, the smooth LPS is called long O-chain LPS. Despite of the differences in the structure of LPS of R. galegae, all strains were eq ually effective in nodulating their hosts. The short O-chain LPS of R. galegae showed many features similar to those of phylogenetically rel ated agrobacteria.