Reconfiguring the <i>Escherichia coli</i> Electron Transport Chain to Enhance <i>trans</i>-2-Decenoic Acid Production

<i>trans</i>-2-Decenoic acid is a pivotal α,β-medium-chain unsaturated fatty acid that serves as an essential intermediary in the synthesis of 10-hydroxy-2-decenoic acid and various pharmaceutical compounds. Biosynthesis yield of <i>trans</i>-2-decenoic acid by decanoic acid has significantly improved in recent years; however, the oxidative stress of <i>Escherichia coli</i> at high fatty acid concentrations restricts the conversion rate. Here, we introduced a combination of rational design and metabolic rewiring of the <i>E. coli</i> electron transport chain (ETC) to improve <i>trans</i>-2-decenoic acid production. Overexpressing ubiquinone (UbQ) biosynthesis genes enhanced the expression of ETC complex III: UbQ to reduce reactive oxygen species (ROS) accumulation. Furthermore, applying rotenone to inhibit ETC complex I improved the electron transfer efficiency of complex II. The integration of Vitamin B₅ and B₂ into the fermentation process increased the activities of fatty acyl-CoA synthetase (^<i>Ma</i><i>MACS</i>) and fatty acyl-CoA dehydrogenase (^<i>Pp</i><i>fadE</i>). Finally, the constructed <i>E. coli</i> BL21(DE3)(Δ<i>fadBJR</i>/pCDFDuet-1-^<i>Pp</i><i>fadE</i>-^<i>Ma</i><i>MACS</i>/pRSFDuet-1-sumo-^<i>Ct</i><i>ydiI</i>-<i>ubiI</i>) strain exhibited a 51.50% decrease in ROS and a 93.33% enhancement in <i>trans</i>-2-decenoic acid yield, reaching 1.45 g/L after 66 h, which is the highest yield reported for flask fermentation. This study reports the feasibility of rewiring the ETC regulation and energy metabolism to improve α,β-UCA biosynthesis efficiency.