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

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.