Production of industrial‐grade polysaccharide B‐1459

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Abstract
A method to make purified polysaccharide synthesized exocellularly from cereal carbohydrates by the bacterium Xanthomonas campestris NRRL B‐1459 and a characterization of its properties have been reported previously by this Laboratory. Because of increasing commercial interest in a less purified polymer, we have extended our work to include production of a lower cost industrial‐grade product. Fermentation of media containing 2.25% corn sugar, seeded with 5% inoculum of X. campestris NRRL B‐1459 and cultured aerobically at 82°F., is complete in 96 hr. The viscous fermented broth contains about 1.5% polymer. A tan product containing approximately 60% polymer and having good viscosity characteristics is obtained by drum drying the fermented broth at steam pressures below 40 p.s.i.g, 287°F. Drying at higher temperatures adversely affects viscosity. A good product is also obtained by spray drying. Cost estimates indicate that 5 million lb./yr. of dried crude solids could be produced for 37 cents/lb. by drum drying or for 41 cents a pound by spray drying.