为了实现L-异亮氨酸的高效生产,提高谷氨酸棒状杆菌YILW生产L-异亮氨酸的产量和生产强度,在详尽分析磷酸盐和玉米浆初始浓度对L-异亮氨酸发酵影响的基础上采用了双底物(玉米浆、磷酸盐)指数流加与双阶段溶氧相结合的控制策略进行L-异亮氨酸发酵。结果表明,最佳磷酸盐和玉米浆浓度分别为1.5 g/L和35 mL/L,此条件下分批补料发酵菌体生物量和L-异亮氨酸产量分别为27.66 g/L和25.89 g/L。在生长阶段进行双底物指数流加并结合双阶段溶氧控制,发酵60 h菌体生物量和L-异亮氨酸产量分别为32.29 g/L和31.32g/L,较优化前分别提高16.73%和20.97%。

As an essential amino acid with branched chain,L-isoleucine( Ile) plays an important role in amino acid market. In order to increase the production and yield of L-isoleucine by Corynebacterium glutamicum YILW,fed batch culture was performed using a two-stage dissolved oxygen control strategy coupled with exponential feeding strategies of the growth limiting nutrients such as core steep liquor and phosphate. The optimal initial concentrations of core steep liquor and phosphate were 35. 0 mL / L and 1. 5 g / L,and the biomass and L-isoleucine production reached 27. 66 g / L and 25. 89 g / L under these conditions. With dual exponential feeding and two-stage dissolved oxygen control strategy,the biomass and L-isoleucine production increased to 32. 29 g / L and 31. 32 g / L after 60 h,which was 16. 73% and 20. 95% higher than those of control,respectively. This work will probably lay a foundation for the control and optimization of L-isoleucine fermentation process on industrial scale.