Studies on dilute solutions and dispersion of the polysaccharide from Xanthomonas campestris NRRL B-1459

Abstract

Some properties of the extracellular polysaccharide produced by the bacterium Xanthomonas campestris NRRL B-1459 were measured in partially purified culture fluids and in liquid systems prepared from thoroughly purified and lyophilized material. High intrinsic viscosities resulted from dispersions and solutions of polysaccharide B-1459 in 0.01m ammonium acetate and 4m urea. Heating a dispersion of B-1459 in 4m urea yielded a true macromolecular solution in which the polysaccharide had an apparent molecular weight of approximately 2 × 106. Lightscattering measurements on culture fluids of B-1459 made 4m in urea gave molecular weights of 13 × 106 and 50 × 106. Various solution-properties and factors that affect the viscosity of dispersions prepared from lyophilized polysaccharide are presented. © 1970.