EXTRACELLULAR POLYSACCHARIDE PRODUCTION BY A RHIZOBIUM SP FROM ROOT-NODULES OF DERRIS SCANDENS

The Rhizobium sp, isolated from the root nodules of the leguminous cli mbing shrub Derris scandens produced a large amount of extracellular p olysaccharides in a yeast extract-mannitol medium in the stationary ph ase of growth. The production was maximum when the medium was suppleme nted with mannitol (3 %), (+)-biotin (3 mg/L) and KNO3 (0.3 %). The ex tracellular polysaccharides contained glucose, galactose and mannose. The possible role of the rhizobial extracellular polysaccharide is dis cussed.