Reconfiguring the Electron Transport Chain to Enhance -2-Decenoic Acid Production.

-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 -2-decenoic acid by decanoic acid has significantly improved in recent years; however, the oxidative stress of at high fatty acid concentrations restricts the conversion rate. Here, we introduced a combination of rational design and metabolic rewiring of the electron transport chain (ETC) to improve -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 B and B into the fermentation process increased the activities of fatty acyl-CoA synthetase () and fatty acyl-CoA dehydrogenase (). Finally, the constructed BL21(DE3)(Δ/pCDFDuet-1--/pRSFDuet-1-sumo--) strain exhibited a 51.50% decrease in ROS and a 93.33% enhancement in -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.