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Enhanced O ‐succinyl‐ l ‐homoserine production by recombinant Escherichia coli ΔIJBB*Trc metL /pTrc‐ metA fbr ‐Trc‐ thrA fbr ‐ yjeH via multilevel fermentation optimization
Author(s) -
Zhu W.Y.,
Niu K.,
Liu P.,
Fan Y.H.,
Liu Z.Q.,
Zheng Y.G.
Publication year - 2021
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/jam.14884
Subject(s) - fermentation , titer , strain (injury) , response surface methodology , escherichia coli , recombinant dna , threonine , biochemistry , box–behnken design , yeast extract , yeast , industrial fermentation , chemistry , biology , food science , chromatography , gene , enzyme , serine , genetics , antibody , anatomy
Abstract Aims Constructing a strain with high yield of O ‐succinyl‐ l ‐homoserine (OSH) and improving the titre through multilevel fermentation optimization. Methods and results OSH high‐yielding strain was first constructed by deleting the thrB gene to block the threonine biosynthesis. Single‐factor experiment was carried out, where a Plackett–Burman design was used to screen out three factors (glucose, yeast and threonine) from the original 11 factors that affected the titre of OSH. The Box–Behnken response surface method was used to optimize the fermentation conditions. Through gene editing and medium optimization, the titre of OSH increased from 7·20 to 8·70 g l −1 in 500 ml flask. Furthermore, the fermentation process and fed‐batch fermentation conditions including pH, temperature, feeding strategy and feeding medium were investigated and optimized. Under the optimal conditions, the titre of OSH reached 102·5 g l −1 , which is 5·6 times higher than before (15·6 g l −1 ). Conclusions O‐succinyl‐ l ‐homoserine fermentation process was established and the combination of response surface methodology and metabolic pathway analysis effectively improved the titre of OSH. Significance and Impact of the Study In this study, the titre of OSH reached the needs for industrial production and the metabolic pathway of OSH was demonstrated for further optimization.