초록
<P>Coenzyme A (CoA)-dependent pathways have been explored extensively for the biosynthesis of fuels and chemicals. While CoA-dependent mechanisms are widely used to elongate carbon chains in a linear fashion, branch-making chemistry has not been incorporated. In this study, we demonstrated the production of isobutanol, a branched-chain alcohol that can be used as a gasoline substitute, using a novel CoA-dependent pathway in recombinant <I>Ralstonia eutropha</I> H16. The designed pathway is constituted of three modules: chain elongation, rearrangement, and modification. We first integrated and optimized the chain elongation and modification modules, and we achieved the production of ∼200 mg/L <I>n</I>-butanol from fructose or ∼30 mg/L from formate by engineered <I>R. eutropha</I>. Subsequently, we incorporated the rearrangement module, which features a previously uncharacterized, native isobutyryl-CoA mutase in <I>R. eutropha</I>. The engineered strain produced ∼30 mg/L isobutanol from fructose. The carbon skeleton rearrangement chemistry demonstrated here may be used to expand the range of the chemicals accessible with CoA-dependent pathways.</P><BR>[FIG OMISSION]</BR>