Huang Jinhai, Chen Zhen, Sun Yan, Liu Dehua
Sheng Wu Gong Cheng Xue Bao. 2015 Oct;31(10):1520-7.
1,3-propanediol is an important chemical used as building block for the synthesis of highly promising polyesters such as polytrimethylene terephthalate. A genetically modified Klebsiella pneumoniae LDH526 can use glycerol as sole carbon source and produce 1,3-propanediol with the titer above 90 g/L. A key factor affecting the production of 1,3-propanediol by the mutant K. pneumoniae is the accurate control of the feeding of glycerol. To generate a robust and reproducible fermentation process of 1,3-propanediol, we designed and optimized an automatically feeding strategy of glycerol based on fermentation kinetics. By coupling the substrate feeding rate with easily observed variables -pH and fermentation time, we have achieved self-starting glycerol feeding and dynamic control of the glycerol concentration during the fermentation process. This automated system allowed us to generate a reproducible, consistent and operator-independent process from lab-scale to production scale. The final concentration of 1,3-propanediol was above 95 g/L after 72 h.
1,3 - 丙二醇是一种重要的化学品，用作合成极具前景的聚酯（如聚对苯二甲酸丙二醇酯）的原料。基因工程改造的肺炎克雷伯氏菌LDH526能够以甘油作为唯一碳源，并生产出滴度高于90 g/L的1,3 - 丙二醇。影响突变型肺炎克雷伯氏菌生产1,3 - 丙二醇的一个关键因素是甘油进料的精确控制。为了建立一个稳定且可重复的1,3 - 丙二醇发酵工艺，我们基于发酵动力学设计并优化了一种甘油自动进料策略。通过将底物进料速率与易于观察的变量——pH值和发酵时间相耦合，我们实现了甘油进料的自动启动以及发酵过程中甘油浓度的动态控制。这个自动化系统使我们能够从实验室规模到生产规模建立一个可重复、稳定且无需操作人员干预的工艺。72小时后，1,3 - 丙二醇的最终浓度高于95 g/L。
