Stepwise metabolic engineering of Escherichia coli to produce triacylglycerol rich in medium-chain fatty acids

Abstract

Enhancement of MCFA flux is aimed at producing TAGs rich in MCFAs.Since both plants and bacteria use a type II FAS system to synthesize fatty acids, many plant MCFA-specific acyl-ACP thioesterases (TEs) have been successfully applied in E. coli for generating high levels of MCFAs [30, 31].[...]the available cellular acyl-CoA and ethanol could also be catalyzed by wax ester synthase activity of AtfA to form FAEE.[...]we then assessed the ability of newly discovered WS/DGAT and RoPAP combinations for TAG production.Figure S7).Because tDGAT was isolated from a thermophilic actinobacterium with an optimal growing temperature of 50 °C [18].[...]it was likely that tDGAT exhibited higher activity at 37 °C compared to 30 °C. Figure 4 Fig. 4 Assessment of medium-chain specific TE for diverting MCFA flux into TAG backbones. a MCFAs from the TAG fraction extracted from strain 2119 carrying different TEs. b TAG content and titer of strain 2119 carrying different TEs. c Fatty acid profile of the TAG fraction extracted from engineered strain 2119 carrying different TEs. d Time course of TAG production yielded by strain 2119 carrying pACYCDuet::RcFatB.