Abstract: Glycerol could be transformed to 1,3-propanediol (1,3-PD) by Klebsiella pneumoniae. Since NADH was required in the process, reductants were considered to affect the formation of 1,3-propanediol. In this work, 40~150 mg/L VC or 20~100 mg/L VE was added into the culture medium to regulate the intracellular redox state (NADH/NAD) of Klebsiella pneumoniae, and the effects of these two reductants on the metabolism of Klebsiella pneumoniae were investigated. It was shown that the concentration of 1,3-propanediol increased by 20%~30% by addition of 150 mg/L VC or 30 mg/L VE into the culture medium. With the increasing 1,3-PD, some byproducts such as ethanol and 2,3-butanediol increased correspondingly, which resulted in an unconspicuous improvement of the yield of 1,3-PD. Rather than addition of these reductants, regulation of metabolic flux was considered to be a feasible attempt to improve the yield of 1,3-PD.

Key words: reductant, vitamin C, vitamin E, Klebsiella pneumoniae, 3-propanediol, NADH

摘要： 通过外源添加还原剂的方式调控细胞内NADH/NAD再生系统的状态，研究了40~150 mg/L VC及20~100 mg/L VE对Klebsiella penumoniae合成1,3-丙二醇的影响，发现外源添加150 mg/L VC或30 mg/L VE均可使1,3-PD合成浓度提高20%~30%；但同时也提高了某些副产物的合成浓度，对代谢流分布的调控作用不明显；1,3-丙二醇得率稍有提高但不显著. 提高1,3-PD得率宜从代谢节点(丙酮酸)通量调节方面考虑.

关键词: 还原剂, 维生素C, 维生素E, Klebsiella pneumoniae, 3-丙二醇, 还原型二磷酸嘧啶核苷酸