克雷伯氏肺炎杆菌HR526快速合成1,3-丙二醇发酵特性研究

Fermentation Characteristics of the Fast Conversion of Glycerol to 1,3-propanediol by Klebsiella pneumoniae HR526

摘要:

研究了实验室筛选的一株高产1,3-丙二醇(PDO)菌株克雷伯氏肺炎杆菌HR526(Klebsiella pneumoniae HR526), 在5 L B. Braun发酵罐进行甘油补料流加发酵30 h, PDO达到91.47 g/L, 胞外代谢通量分析显示, PDO在对数中期通量达到最大, 而乳酸在稳定期通量达到最大。结合酶学检测分析了PDO合成关键酶PDO氧化还原酶(PDOR)、甘油脱水酶(GDHt)和甘油脱氢酶(GDH)酶活的变化, PDO氧化还原酶活性在对数中期达到最高, 甘油脱水酶/甘油脱氢酶在对数期远大于稳定期、衰退期, 与代谢通量变化一致甘油脱水酶/甘油脱氢酶活性比例不均衡是3-HPA对数期积累的原因, PDO合成主要集中在对数期, 是生长偶联的代谢产物。

Abstract:

The glycerol fed-batch fermentations with a novel isolated 1,3-propanediol production strains, designed Klebsiella pneumoniae HR526 were performed in 5 L B. Braun fermenter. The result indicated that 91.47 g/L 1,3-propanediol was produced in 30 h. The extracellular metabolic flux was calculated, indicating PDO flux reached the maximum value in the mid logarithmic growth phase, whereas lactic acid flux reached the maximum value in the stable phase. This article also analyzed the key enzyme activity of PDO synthesis, the maximum PDOR activity was reached in the mid of the logarithmic growth phase, the ratio of the GDHt/PDO and GDHt/GDH is rather higher in the logarithmic growth phase than in the stable, leading to 3-HPA accumulation during the exponential growth phase. The production of PDO is closely related to cell growth.