Expanding metabolic pathway for de novo biosynthesis of the chiral pharmaceutical intermediate l-pipecolic acid in Escherichia coli

Microbial Cell Factories

卷:16

Xin Wang¹  Pingkai Ouyang¹  Jing Wang¹  Hanxiao Ying¹  Sha Tao¹  Weichao Ma¹  Kequan Chen¹ 

[1] State Key Laboratory of Materials Oriented Chemical Engineering;

关键词: Chiral intermediate biosynthesis;    Lysine cyclodeaminase;    l-Pipecolic acid;    Metabolic engineering;    Cofactor engineering;   

DOI  :  10.1186/s12934-017-0666-0

来源: DOAJ

【 摘 要 】

Abstract Background The six-carbon circular non-proteinogenic compound l-pipecolic acid is an important chiral drug intermediate with many applications in the pharmaceutical industry. In the present study, we developed a metabolically engineered strain of Escherichia coli for the overproduction of l-pipecolic acid from glucose. Results The metabolic pathway from l-lysine to l-pipecolic acid was constructed initially by introducing lysine cyclodeaminase (LCD). Next, l-lysine metabolic flux from glucose was amplified by the plasmid-based overexpression of dapA, lysC, and lysA under the control of the strong trc promoter to increase the biosynthetic pool of the precursor l-lysine. Additionally, since the catalytic efficiency of the key enzyme LCD is limited by the cofactor NAD+, the intracellular pyridine nucleotide concentration was rebalanced by expressing the pntAB gene encoding the transhydrogenase, which elevated the proportion of LCD with bound NAD+ and enhanced l-pipecolic acid production significantly. Further, optimization of Fe2+ and surfactant in the fermentation process resulted in 5.33 g/L l-pipecolic acid, with a yield of 0.13 g/g of glucose via fed-batch cultivation. Conclusions We expanded the metabolic pathway for the synthesis of the chiral pharmaceutical intermediate l-pipecolic acid in E. coli. Using the engineered E. coli, a fast and efficient fermentative production of l-pipecolic acid was achieved. This strategy could be applied to the biosynthesis of other commercially and industrially important chiral compounds containing piperidine rings.

【 授权许可】

Unknown