A miniature of soluble methane monooxygenase enables Escherichia coli to rapidly produce methanol with high yield

Abstract

Abstract Soluble methane monooxygenase (sMMO) oxidizes a wide range of carbon feedstocks (C1 to C8) directly using intracellular NADH and is a useful means in developing green routes for industrial manufacturing of chemicals; however, the high-throughput biosynthesis of active recombinant sMMO and the ensuing catalytic oxidation have so far been unsuccessful due to the structural and functional complexity of sMMO, comprised of functionally complementary, three enzyme components, which remains a major challenge for its industrial applications. Here we developed a catalytically active miniature of sMMO (mini-sMMO) through an optimal reassembly of minimal and modified components of sMMO on catalytically inert and stable apoferritin scaffold, with demonstrating the molecular characteristics in detail through in silico and experimental analyses and verifications. Notably, the in-situ methanol production in the high-cell-density culture of mini-sMMO-expressing recombinant Escherichia coli resulted in a remarkably higher productivity compared to the traditional methanotrophic production.