Modular optimization free fatty acids synthetic system of e.coli

Abstract

The biosynthesis of fatty acid in vivo is efficient way for carbon chain extension, whose products are suitable for further synthesizing bulk chemicals and liquid fuels. Targeting on improving the production of free fatty acids in E.coli, and fusing with the thought of modular transformation and chassis adaptation in synthetic biology, in the E.coli BL21 (DE3) chassis cells where fadE gene was knocked-out through the phage λ Red recombinase system, the free fatty acids biosynthesis pathway was divided into fatty acyl-acyl carrier protein (ACP) releasing downstream module (thioesterase from E.coli and from Umbellularia californica) and malonyl-ACP synthesis upstream module (acetyl-CoA carboxylase，ACC from E. coli and Corynebacterium glutamicum). Thus the functional coordination and adaptation with chassis cells can be realized, thereby improving the modularization of genes of different functions and origins in vivo and the production of medium or long-chain free fatty acids of certain length. Final yield of experimental strands can be as high as 242.2mg/L, 115-fold of that of E.coli chassis cells of 2.1mg/L, making the engineered strands capable to obtain high yield of fatty acids, and further laying a foundation for the follow-up production and studies.