Chemical analysis of exocellular, acid polysaccharides from seven Rhizobium strains

A comparative, chemical analysis of the acid exopolysaccharides from seven Rhizobium strains, involving the taxonomic groups Rhizobium meliloti, Rh. trifolii, Rh. phaseoli, and Rh. leguminosarum, is presented. Apart from the polysaccharide from Rh. meliloti, which is known to lack uronic acid, no significant differences in the carbohydrate composition were found. The two non-nitrogen-fixing strains infective (Coryn), and non-infective (Bart A)] gave polysaccharides which differ from those produced by the infective and nitrogen-fixing strains in the detailed structural features. This difference is expressed in the pattern of periodate oxidation and cation-binding capacity.