Exopolysaccharides and lipopolysaccharides from a fast-growing strain of Rhizobium japonicum (USDA191)

Abstract

Analysis of the exopolysaccharides from Rhizobium japonicum USDA191 showed substantial amounts of mannose (22.5%) and uronic acids (13.4%). These sugars are normally absent in the fast growers like Rhizobium meliloti. In addition USDA191 contained pyruvate (5.1%), which is normally absent in slow-growing strains of Rhizobium japonicum. The heterogeneity in the exopolysaccharide composition of strain 191 indicates a closer similarity with the slow-growing Rhizobium japonicum. SDS-urea polyacrylamide gel analysis of the lipopolysaccharides also reflects this heterogeneity.