INFLUENCE OF PHOSPHATE ON RHAMNOSE-CONTAINING EXOPOLYSACCHARIDE RHEOLOGY AND PRODUCTION BY KLEBSIELLA I-714

Physiological conditions enhancing rhamnose-containing polysaccharide synthesis by klebsiella I-714 were studied in batch culture (0.3-1 and 2-1 bioreactors). The four carbon sources tested, sucrose, sorbitol, Neosorb and Cerelose, allowed exopolysaccharide production, Larger amo unts of polymer were produced when high carbon:nitrogen ratios and com plex nitrogen sources were used. Exopolysaccharide synthesis was great est at 30 degrees C, which was a suboptimal growth temperature. A redu ction in the phosphate content of the medium enhanced rhamnose-contain ing polysaccharide production. When the initial carbon source concentr ation was augmented, byproducts other than exopolysaccharide were form ed. Rhamnose-containing polysaccharide rheology can be modulated by ch anging the phosphate content of the medium.