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 Ralstonia eutropha 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 n-butanol from fructose or ∼30 mg/L from formate by engineered R. eutropha. Subsequently, we incorporated the rearrangement module, which features a previously uncharacterized, native isobutyryl-CoA mutase in R. eutropha. 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.

中文翻译：

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辅酶A-酰基化碳链的重排使得富营养的Ralstonia eutropha能够通过新途径合成异丁醇

辅酶A（CoA）依赖的途径已被广泛探索用于燃料和化学物质的生物合成。虽然依赖于CoA的机制已广泛用于以线性方式延长碳链，但尚未纳入分支制造化学法。在这项研究中，我们证明了异丁醇的生产，该支链醇可以用作汽油替代品，它使用了重组Ralstonia eutropha H16的新型CoA依赖性途径。设计的路径由三个模块组成：链延长，重排和修饰。我们首先整合并优化了链的延伸和修饰模块，并通过工程化的富营养R. eutropha实现了从果糖生产约200 mg / L正丁醇或从甲酸生产约30 mg / L。。随后，我们引入重排模块中，由于具有一预先未表征的，天然的异丁酰-CoA变位酶富氧罗尔斯。该工程菌株从果糖中产生了约30 mg / L的异丁醇。此处展示的碳骨架重排化学可用于扩大可通过CoA依赖性途径获得的化学物质的范围。