Evaluation of the Efficiency of Functional Reversal of Fatty Acid Β-Oxidation in Escherichia coli upon the Action of Various Native Acyl-CoA Dehydrogenases

Abstract

Abstract Using Escherichia coli strain MG1655 lacIQ, ∆ackA-pta, ∆poxB, ∆ldhA, ∆adhE, ∆fadE, PL‑SDφ10-atoB, Ptrc-ideal-4-SDφ10-fadB, PL-SDφ10-tesB, ∆yciA as a core strain, the efficiency of the reversal of fatty acid β-oxidation upon the action of native cellular enzymes capable of serving as acyl-CoA dehydrogenases was examined. Increased expression of fadE, fabI, and ydiO/ydiQRST genes encoding the corresponding enzymes was ensured in derivatives of the core strain by substituting their native regulatory regions with artificial regulatory element Ptrc-ideal-4-SDφ10. A three-turn reversal of the cycle in the engineered recombinants was demonstrated that was accompanied by considerable secretion of butyric, caproic, and caprylic acids. The highest level of six- and eight-carbon carboxylates production was achieved upon the overexpression of the fabI gene, while the lowest levels of secretion of the corresponding compounds were demonstrated by the strain with the enhanced expression of the ydiO and ydiQRST genes. The recombinant with the individually enhanced expression of ydiO did not produce detectable amounts of the derivatives of the complete and successful β-oxidation reversal.