重组谷氨酸棒杆菌发酵L-苯丙氨酸培养基的优化

Optimization of the medium for L-phenylalanine production by recombinant Corynebacterium glutamicum

摘要:

【目的】提高重组谷氨酸棒杆菌发酵L-苯丙氨酸(L-phenylalanine，L-Phe)的产量。【方法】使用正交试验设计以及响应面优化法分别对种子培养基及发酵培养基进行优化，确定了重组谷氨酸棒杆菌发酵L-Phe的最佳种子培养基及最佳发酵培养基。【结果】重组谷氨酸棒杆菌发酵L-Phe最佳种子培养基(g/L)：葡萄糖 25.0，玉米浆 25.0，硫酸铵 15.0，硫酸镁1.0，磷酸二氢钾2.0，尿素2.0，pH 6.8?7.0；最佳发酵培养基(g/L)：葡萄糖 110.0，玉米浆7.0，硫酸铵25.0，硫酸镁1.0，磷酸二氢钾1.0，柠檬酸钠2.0，谷氨酸1.0，碳酸钙25.0，pH 6.8?7.0；在最佳培养基条件下L-Phe产量最高达到9.14 g/L，较优化前的7.46 g/L提高了22.5%。【结论】通过正交试验和响应面分析对重组谷氨酸棒杆菌发酵L-Phe培养基进行优化，明显提高了L-Phe的产量，并确定了葡萄糖、玉米浆和硫酸铵为发酵培养基中影响L-Phe产量的3个关键因子。研究结果为L-Phe的发酵放大提供了依据。

关键词:谷氨酸棒杆菌，L-苯丙氨酸，响应面优化，正交试验

Abstract:

[Objective] In order to enhance production of L-phenylalanine (L-Phe) by recombinant Corynebacterium glutamicum, the composition of culture medium was optimized. [Methods] Using orthogonal experiment and response surface methodology, the optimal medium of seed and fermentation was obtained for the production of L-Phe by recombinant C. glutamicum. [Results] The optimal seed medium (g/L) was comprised of glucose 25.0, corn steep liquor 25.0, (NH4)2SO4 15.0, MgSO4 1.0, KH2PO4 2.0, Urea 2.0 and pH was 6.8?7.0. The optimal fermentation medium (g/L) contained glucose 110.0, corn steep liquor 7.0, (NH4)2SO4 25.0, MgSO4 1.0, KH2PO4 1.0, sodium citrate 2.0, glutamic acid 1.0, CaCO3 25.0 and pH 6.8?7.0. Accordingly, L-Phe production (9.14 g/L) was increased by 22.5%. [Conclusion] The production of L-Phe was significantly increased after optimization and three key factors (glucose, corn steep liquor and (NH4)2SO4) were identified for the production of L-Phe through the orthogonal experiment and response surface analysis, which might provide a foundation for the scale-up culture in the future.

Key words:Corynebacterium glutamicum, L-phenylalanine, Response surface methodology, Orthogonal experiment