ELECTROPHORETIC BEHAVIOR AND SIZE DISTRIBUTION OF THE ACIDIC POLYSACCHARIDES PRODUCED BY THE BACTERIA BP BRADYRHIZOBIUM (CHAMAECYTISUS) STRAIN BGA-1 AND BRADYRHIZOBIUM-JAPONICUM USDA-110

The electrophoretic behavior in polyacrylamide gels of the acidic poly saccharides produced by the soil bacteria Bradyrhizobium (Chamaecytisu s) strain BGA1 and Bradyrhizobium japonicum USDA 110 has been studied. Both polysaccharides were polydisperse, producing a ladder-like patte rn after fixation with Alcian Blue and silver staining of the gel. The polysaccharide molecules were separated according to their size, and they behaved as a collection of flexible random coils of different siz e and similar charge/mass ratio. The electrophoretic behavior was not affected by the presence of acetyl groups in the polysaccharide. The r ange of molecular weights of the exopolysaccharide produced by B. japo nicum USDA110 was wider and with larger molecules than that of the pol ysaccharide produced by strain BGA1. The resolution was dependent on t he electrophoresis buffer; the best results were achieved with Tris-bo rate; in Tris-glycine buffer, the resolution was worse, and it was not improved by the addition of sodium dodecyl sulfate (SDS).