研究了用于谷胱甘肽合成的温度诱导型重组大肠杆菌的补料分批发酵,通过葡萄糖的脉冲补入,结合溶氧反馈控制技术,实时控制发酵过程中乙酸的产生.在此基础上,进一步考察了在谷胱甘肽合成酶系诱导表达阶段,流加酵母粉和蛋白胨时重组大肠杆菌的补料分批发酵过程.结果发现,脉冲补料-溶氧反馈控制技术在流加酵母粉和蛋白胨的补料分批发酵中仍能得到很好的应用,乙酸浓度可被有效地控制在2.5g/L以下.通过比较诱导表达阶段流加不同组成的补料液成分,发现添加适量酵母粉和蛋白胨可促进谷胱甘肽合成酶系的表达,在42℃诱导4h收获的重组大肠杆菌酶法合成谷胱甘肽达到2.46g/L.
The fed-batch fermentation of temperature induced recombinant E. coli for glutathione production was investigated. It is demonstrated that acetic acid could be controlled at low concentration by using dissolved oxygen responses to glucose feeding pulse. Based on the results, the fed-batch fermentation of the addition of yeast extracts and tryptone together with glucose in the expression phase of glutathione synthetic enzymes system was further studied. Applying the feedback control of dissolved oxygen responses to pulse in glucose feeding, acetic acid accumulation was successfully prevented. And the addition of yeast extracts and tryptone was beneficial to the expression of glutathione synthetic enzymes system. The concentration of glutathione reached 2.46 g/L in the enzymatic synthesis by using recombinant E. coli induced for 4 h at 42℃.