两阶段溶氧控制及FeSO4添加对谷氨酸棒杆菌合成4-羟基异亮氨酸的影响

Effects of two-stage DO control and FeSO4 addition on 4-hydroxyisoleucine production by Corynebacterium glutamicum

优化4-羟基异亮氨酸发酵过程中溶氧水平及FeSO4添加量,以提高其发酵水平。结合菌株Corynebacterium glutamicum HIL18及4-羟基异亮氨酸合成特点,首先考察不同溶氧水平及两阶段溶氧控制对4-羟基异亮氨酸发酵的影响。然后考察FeSO4添加对其发酵的作用。20%溶氧有利于4-羟基异亮氨酸的合成。利用两阶段溶氧控制工艺(0~20h、20%溶氧;20~64h、30%溶氧)经64h发酵,4-羟基异亮氨酸产量达到38.7g/L,较未使用该工艺提高11.2%。采用两阶段FeSO4添加策略(初始浓度为65μmol/L、20h添加30μmol/L),4-羟基异亮氨酸的产量达到43.4g/L。采用优化后的工艺使得4-羟基异亮氨酸产量较优化前提高27.3%。获得了4-羟基异亮氨酸发酵过程中两阶段溶氧控制及FeSO4添加工艺。该结果为4-羟基异亮氨酸的高效发酵合成提供参考。

Effects of DO levels and two-stage DO control strategy on 4-hydroxyisoleucine production were investigated,followed by analyzing the effects of two-stage FeSO 4 addition.The results indicated that 20%DO was suitable for 4-hydroxyisoleucine synthesis during one-stage DO control process.During two-stage DO control process(20%DO for 0-20 h and 30%for 20-64 h),38.7 g/L 4-hydroxyisoleucine was obtained,which was 11.2%higher than that at 20%DO.By using two-stage FeSO 4 addition strategy(65μmol/L for primary concentration and 30μmol/L FeSO 4 added at 20 h),the production of 4-hydroxyisoleucine increased to 43.4 g/L,which was 27.3%higher than the control.In conclusion,the strategy of two-stage DO control and FeSO 4 addition provides a reference for highly efficient production of 4-hydroxyisoleucine.