OPTIMIZATION OF BATCH FERMENTATION CONDITIONS FOR DEXTRAN PRODUCTION

The nutrient medium (containing sucrose, yeast extract and K2HPO4), te mperature and initial pH conditions were optimised for batch dextran p roduction in shake flask fermentations using a strain of Leuconostoc m esenteroides NRRL B 512 (F). A 2(5-1) fractional factorial central com posite experimental design was attempted. Multistage Monte Carlo optim ization program was used to maximize the multiple regression equation obtained. The optimal values of tested variables for maximal dextran p roduction were found to be: sucrose, 300 g/l; yeast extract, 10 g/l; K 2HPO4, 30 g/l; temperature, 23 degrees C and initial pH 8.3 with a pre dicted dextran yield of 154 g/l.