CARBOHYDRATE, NUCLEIC ACID, AND PROTEIN COMPOSITION OF EXTRACELLULAR MATERIAL FROM RHIZOBIUM JAPONICUM

Abstract

The water-soluble phenol-extracted fractions of the extracellular material from four strains of Rhizobium japonicum, differing in nodulating abilities, were analyzed by both chemical and physical methods to determine if there were any compositional similarities or differences in the carbohydrate, nucleic acid or protein fractions which might be related to the nodulation process. The composition of the water-soluble phenol-extract fraction of all four strains was essentially the same. In all four strains this fraction contained 3-9% carbohydrate, 5-15% ribonucleic acid, and less than 1% protein. The carbohydrate contained glucose, galactose, rhamnose, mannose, and glucosamine, plus two unidentified components. No uronic acids were present. The carbohydrate and nucleic acid moieties were partially separated on DEAE-Sephadex. Amino acid analyses indicated the protein to be of an acidic nature. On the basis of these data it would appear that the fractions of the extracellular material analyzed did not differ and could not be associated with a specific role in the nodulation process.