关键词: 3-丙二醇, 克雷伯氏菌突变体, 发酵, 统计优化, 响应面法

Abstract: Response surface methodology (RSM) was employed to optimize fermentation parameters for high-level production of 1,3-propanediol(1,3-PD) by the Klebsiella pneumoniae mutant Kp-M2. Based on the Plackett-Burman design, original concentration of glycerol, original pH and seed age were selected as the most critical parameters. The center points of these three parameters were determined using the steepest accent (descent), and all three parameters were then optimized by the Box-Behnken design. A maximum 1,3-PD concentration of 21.6 g/L was predicted by the optimized glycerol concentration (57 g/L), pH (7.3) and seed age (10 h). Using these three optimized parameters, 20.7 g/L 1,3-PD was obtained from flask fermentation, which represented a 30% increase over that obtained under non-optimized conditions. Under batch and fed-batch fermentations using the same optimized parameters, the concentration of 1,3-PD increased to 29.5 and 92.0 g/L, respectively, compared to 19.9 and 76.7 g/L previously obtained for non-optimized fermentation conditions. This showed that RSM could be effectively used to enhance the production of 1,3-PD via fermentation.

Key words: 3-propanediol, Klebsiella pneumoniae mutant, fermentation, statistical optimization, response surface methodology