Metabolic Engineering Strategies to Produce Medium-Chain Oleochemicals via Acyl-ACP:CoA Transacylase Activity
CABBI Theme: Conversion
Keywords: Genome Engineering, Genomics
Yan, Q., Cordell, W.T., Jindra, M.A., Courtney, D.K., Kuckuk, M.K., Chen, X., Pfleger, B.F. Feb. 24, 2022. “Metabolic-Modeling—Yield-Analysis-of-PhaG.” GitHub Repository, https://github.com/Pfleger-Lab/Metabolic-Modeling—Yield-Analysis-of-PhaG.
Microbial lipid metabolism is an attractive route for producing oleochemicals. The predominant strategy centers on heterologous thioesterases to synthesize desired chain-length fatty acids. To convert acids to oleochemicals (e.g., fatty alcohols, ketones), the narrowed fatty acid pool needs to be reactivated as coenzyme A thioesters at cost of one ATP per reactivation – an expense that could be saved if the acyl-chain was directly transferred from ACP- to CoA-thioester. Here, we demonstrate such an alternative acyl-transferase strategy by heterologous expression of PhaG, an enzyme first identified in Pseudomonads, that transfers 3-hydroxy acyl-chains between acyl-carrier protein and coenzyme A thioester forms for creating polyhydroxyalkanoate monomers. We use it to create a pool of acyl-CoA’s that can be redirected to oleochemical products. Through bioprospecting, mutagenesis, and metabolic engineering, we develop three strains of Escherichia coli capable of producing over 1 g/L of medium-chain free fatty acids, fatty alcohols, and methyl ketones.
- FAME Results
- Plasmid Maps
Yan, Q., Cordell, W.T., Jindra, M.A., Courtney, D.K., Kuckuk, M.K., Chen, X., Pfleger, B.F. March 25, 2022. “Metabolic Engineering Strategies to Produce Medium-Chain Oleochemicals via Acyl-ACP:CoA Transacylase Activity.” Nature Communications 13:1619. DOI: 10.1038/s41467-022-29218-3.