Dynamics of production of extracellular polysaccharides by nodule bacteria.

The dynamics of the accumulation of the extracellular polysaccharides synthesized by nodule bacteria and the possibility of their assimilation by these bacteria as a source of carbon was studied. When nodule bacteria were cultured for 20 days in a medium containing glucose, an increase in the titer of the bacteria and the accumulation of extracellular polysaccharides was observed in the first three days. After this the titer of the nodule bacteria decreased with a decrease in the glucose in the medium, but the amount of extracellular polysaccharide synthesized did not increase. These data suggest that extracellular polysaccharides are not assimilated by nodule bacteria as a source of carbon and evidently are protective substances for the cells.