A non-carboxylative route for the efficient synthesis of central metabolite malonyl-CoA and its derived products

Acetyl coenzyme A (CoA) carboxylation is the natural route for endogenous malonyl-CoA formation; however, this pathway presents slow kinetics, carbon and energy inefficiencies, tight regulations and a complicated architecture. These shortcomings limit flux towards malonyl-CoA and become a bottleneck towards the biosynthesis of malonyl-CoA-derived products (MDPs). Here, we design the non-carboxylative malonyl-CoA pathway as a non-natural route for malonyl-CoA biosynthesis, independent from acetyl-CoA. The designed pathway features enzymes such as β-alanine-pyruvate transaminase and malonyl-CoA reductase, exhibits fast kinetics and circumvents tight regulations and the architecture associated with the natural pathway. Furthermore, introducing this pathway into microbes enhances the production of MDPs, including short-chain fatty acids and representative phenol, quinone, alkene, aminoglycoside and macrolide polyketide families, such as spinosad. In summary, this malonyl-CoA formation pathway avoids intrinsic inefficiencies of the natural pathway and can serve as a versatile platform for obtaining MDPs that could be used as fuels, fine chemicals and pharmaceuticals.