pH值对克雷伯氏肺炎杆菌发酵甘油产1,3-丙二醇的影响与控制

Research of Influence of pH Value on the Fermentation of Glycerol to 1,3-Propanediol by Klebsiella Pneumoniae

在克雷伯氏肺炎杆菌发酵甘油产1,3-丙二醇(1,3-PD)的过程中,不同的pH值控制对菌体生长、产物和副产物的生成有着重要的影响。通过对发酵过程中不同pH值控制下的代谢分析,发现pH值较低时菌体生长较慢,有利于副产物2,3-丁二醇的生成;pH值较高时菌体生长较快,有利于副产物乳酸的生成。通过两阶段pH值控制策略,即在发酵的前14 h控制pH值为7.0、后16 h控制pH值为6.3,有效地抑制了乳酸的生成,1,3-PD的最终浓度达到67.32 g.L-1,甘油的摩尔转化率达到61%。

During the fermentation of glycerol to 1,3-propanediol （1,3-PD） by Klebsiella pneurnoniae, different pH value control strategy had a significant impact on cell growth and the biosynthesis of products and byproducts. Through the metabolic analysis of fermentation process under different pH value controls, it was found that the cell growth rate was slow, the yield of 2,3-butanediol increased under low pH value; the cell growth rate was high,the yield of lactate increased under high pH value. By two-stage control of pH value,the level of 1,3-PD production was enhanced and the production of lactate was effectively inhibited. When the pH value was controlled at 7.0 in the first 14 h of the fermentation and at 6.3 in the following 16 h, the final concentration of 1,3-PD and the molar conversion of glycerol to 1,3-PD were 67.32 g · L-1 ,61% ,respectively.