Metabolic Engineering of Escherich coli to Enhance the Production of Medium-chain Fatty Acids

doi:10.7506/spkx1002-6630-201321027

Abstract

Abstract:

Medium-chain fatty acids (MCFAs) are the major components of medium-chain triglycerides (MCT), which
play an important role in the food additive industry. In this study, the production of MCFAs was greatly enhanced by
overexpressed thioesterase gene of Umbellulana california (BTE) in E. coli. In addition, the location of the produced
MCFAs and the effect of synthesized MCFAs on the composition of membrane phospholipids were also determined. The
results indicated that MCFAs were mainly located in E. coli, and their production had little effect on the composition of
membrane phospholipids. To further improve the production of MCFAs, strategies including co-overexpression of acetyl-
CoA carboxylase (ACCase) and the optimization of the expression level of thioesterase BTE were also carried out. Finally,
188.9 mg/L MCFAs were achieved, representing a rather high production of MCFAs. Meanwhile, the MCFAs accounted for
over 85% of the total free fatty acids, suggesting the high-specificity production of MCFAs.

Key words: medium-chain fatty acid, Escherichia coli, thioesterase, metabolic engineering

CLC Number:

Q815

LIU Qiang1,2，ZHENG Yan-ning2,3，JIANG Xing-lin2,3，LIU Dong-jie1，QIN Wen1,*，XIAN Mo2. Metabolic Engineering of Escherich coli to Enhance the Production of Medium-chain Fatty Acids[J]. FOOD SCIENCE, 2013, 34(21): 131-135.

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