초록
<P><B>ABSTRACT</B></P><P>A novel strategy to finely control the electron transfer chain (ETC) activity of <I>Escherichia coli</I> was established. In this study, the fine‐tuning of the ubiquinone biosynthesis pathway was applied to further controlling ETC function in coenzyme Q8 biosynthesis‐deficient <I>E. coli</I> strains, HW108 and HW109, which contain mutations in <I>ubiE</I> and <I>ubiG</I>, respectively. A competing pathway on the intermediate substrates of the Q8 synthesis pathway, catalyzed by diphosphate:4‐hydroxybenzoate geranyltransferase (PGT‐1) of <I>Lithospermum erythrorhizon</I>, was introduced into these mutant strains. A nearly theoretical yield of lactate production can be achieved under fully aerobic conditions via an in vivo, genetically fine‐tunable means to further control the activity of the ETC of the Q8 biosynthesis‐deficient <I>E. coli</I> strains. Biotechnol. Bioeng. 2015;112: 1720–1726. © 2015 Wiley Periodicals, Inc.</P>