Modular engineering of <i>Escherichia coli</i> for high-level production of l-tryptophan.

Shuang Ding; Xiulai Chen; Cong Gao; Wei Song; Jing WU; Wanqing Wei; Jia Liu; Liming Liu

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Modular engineering of Escherichia coli for high-level production of l-tryptophan.

Author: Shuang DING ¹ ; Xiulai CHEN ¹ ; Cong GAO ¹ ; Wei SONG ² ; Jing WU ² ; Wanqing WEI ¹ ; Jia LIU ¹ ; Liming LIU ¹
Author Information

1. State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China.
2. School of Life Sciences and Health Engineering, Jiangnan University, Wuxi 214122, Jiangsu, China.
Publication Type:Journal Article
Keywords: Escherichia coli; l-tryptophan; metabolic engineering; modular engineering
MeSH: Escherichia coli/metabolism*; Tryptophan; Metabolic Engineering; Bioreactors; Metabolic Networks and Pathways
From: Chinese Journal of Biotechnology 2023;39(6):2359-2374
CountryChina
Language:Chinese
Abstract: As an essential amino acid, l-tryptophan is widely used in food, feed and medicine sectors. Nowadays, microbial l-tryptophan production suffers from low productivity and yield. Here we construct a chassis E. coli TRP3 producing 11.80 g/L l-tryptophan, which was generated by knocking out the l-tryptophan operon repressor protein (trpR) and the l-tryptophan attenuator (trpL), and introducing the feedback-resistant mutant aroG^fbr. On this basis, the l-tryptophan biosynthesis pathway was divided into three modules, including the central metabolic pathway module, the shikimic acid pathway to chorismate module and the chorismate to tryptophan module. Then we used promoter engineering approach to balance the three modules and obtained an engineered E. coli TRP9. After fed-batch cultures in a 5 L fermentor, tryptophan titer reached to 36.08 g/L, with a yield of 18.55%, which reached 81.7% of the maximum theoretical yield. The tryptophan producing strain with high yield laid a good foundation for large-scale production of tryptophan.