OPTIMIZATION OF FERMENTATION CONDITIONS FOR PRODUCTION OF EXOPOLYSACCHARIDE BY BACILLUS-POLYMYXA

Production of exopolysaccharide (EPS) from a strain of Bacillus polymy xa was studied. Sucrose and potassium nitrate were found to be efficie nt carbon and nitrogen sources, respectively, for the production of th e EPS. EPS production increased with the increase of sucrose concentra tion, probably due to the facilitated carbon uptake. Optimal pH was 7- 8, and a sufficient supply of oxygen was needed for the EPS production . It was noted that the EPS synthesis by this B. polymyxa was growth-a ssociated, indicating that a sufficient supply of nutrients was requir ed for a high production of the EPS. As high as 54 g/l of EPS with a y ield of 63% (g EPS/g sucrose) was obtained in 48 h of fed-batch cultiv ation with intermittent feeding of sucrose and potassium nitrate.