甘油连续生物歧化过程培养基和pH调控策略研究

设计了三种不同的培养基和三种pH调控方式，考察了钠、钾和铵离子对甘油连续生物歧化过程的影响，从代谢调控的角度分析了连续发酵实验结果。研究表明，用氢氧化钠调节pH将对底物过量条件下甘油代谢途径中的甘油脱氢酶产生抑制作用，使生物量和1，3－丙二醇的产率下降。在培养基含有足够铵的情况下，可以用氢氧化钾控制pH。采取无铵培养基和氨水并用的策略是可行的。

Studies on Medium Design and pH Control Strategy in the Bioconversion of Glycerol to 1,3-propanediol

The influences of three monovalent cations (Na+, K+, and NH4+) on bioconversion of glycerol to 1,3-propanediol by Klebsiella pneumoniae were investigated by designing three different media and pH control strategies in terms of metabolic control. Experimental results showed that glycerol dehydrogenase, one of the key enzymes of glycerol conversion, was inhibited by high concentration of Na+ under substrate-excess conditions, leading to a decline of yields of biomass and 1,3-propanediol on glycerol. It is feasible to adjust pH by using KOH in a medium consisting of enough NH4+ or using ammonia in a medium without NH4+ and Na+ in continuous cultures.