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Metabolic engineering of Escherichia coli for microbial production of L‐methionine
Author(s) -
Huang JianFeng,
Liu ZhiQiang,
Jin LiQun,
Tang XiaoLing,
Shen ZhenYang,
Yin HuanHuan,
Zheng YuGuo
Publication year - 2017
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.26198
Subject(s) - methionine , escherichia coli , biochemistry , fermentation , chemistry , overproduction , titer , lysine , metabolic engineering , biosynthesis , beta galactosidase , biology , enzyme , amino acid , gene , antibody , immunology
L‐methionine has attracted a great deal of attention for its nutritional, pharmaceutical, and clinical applications. In this study, Escherichia coli W3110 was engineered via deletion of a negative transcriptional regulator MetJ and over‐expression of homoserine O‐succinyltransferase MetA together with efflux transporter YjeH, resulting in L‐methionine overproduction which is up to 413.16 mg/L. The partial inactivation of the L‐methionine import system MetD via disruption of met I made the engineered E. coli Δ met J Δ met I/pTrcA*H more tolerant to high L‐ethionine concentration and accumulated L‐methionine to a level 43.65% higher than that of E. coli W3110 Δ met J/pTrcA*H. Furthermore, deletion of lys A, which blocks the lysine biosynthesis pathway, led to a further 8.5‐fold increase in L‐methionine titer of E. coli Δ met J Δ met I Δ lys A/pTrcA*H. Finally, addition of Na 2 S 2 O 3 to the media led to an increase of fermentation titer of 11.45%. After optimization, constructed E. coli Δ met J Δ met I Δ lys A/pTrcA*H was able to produce 9.75 g/L L‐methionine with productivity of 0.20 g/L/h in a 5 L bioreactor. This novel metabolically tailored strain of E. coli provides an efficient platform for microbial production of L‐methionine. Biotechnol. Bioeng. 2017;114: 843–851. © 2016 Wiley Periodicals, Inc.