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Pathway engineering of Escherichia coli for α‐ketoglutaric acid production
Author(s) -
Chen Xiulai,
Dong Xiaoxiang,
Liu Jia,
Luo Qiuling,
Liu Liming
Publication year - 2020
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.27456
Subject(s) - escherichia coli , citric acid cycle , metabolic engineering , tricarboxylic acid , biochemistry , pyruvate carboxylase , bioreactor , isocitrate dehydrogenase , dehydrogenase , acetyl coa , bioproduction , metabolic pathway , phosphoenolpyruvate carboxylase , chemistry , biology , enzyme , organic chemistry , gene
α‐Ketoglutaric acid (α‐KG) is a multifunctional dicarboxylic acid in the tricarboxylic acid (TCA) cycle, but microbial engineering for α‐KG production is not economically efficient, due to the intrinsic inefficiency of its biosynthetic pathway. In this study, pathway engineering was used to improve pathway efficiency for α‐KG production in Escherichia coli . First, the TCA cycle was rewired for α‐KG production starting from pyruvate, and the engineered strain E. coli W3110Δ4‐PCAI produced 15.66 g/L α‐KG. Then, the rewired TCA cycle was optimized by designing various strengths of pyruvate carboxylase and isocitrate dehydrogenase expression cassettes, resulting in a large increase in α‐KG production (24.66 g/L). Furthermore, acetyl coenzyme A (acetyl‐CoA) availability was improved by overexpressing acetyl‐CoA synthetase, leading to α‐KG production up to 28.54 g/L. Finally, the engineered strain E. coli W3110Δ4‐P (H) CAI (H) A was able to produce 32.20 g/L α‐KG in a 5‐L fed‐batch bioreactor. This strategy described here paves the way to the development of an efficient pathway for microbial production of α‐KG.