Engineering Escherichia coli for Conversion of Glucose to Medium-Chain ω-Hydroxy Fatty Acids and α,ω-Dicarboxylic Acids

In search of sustainable approaches to plastics production, many efforts have been made to engineer microbial conversions of renewable feedstock to short-chain (C2-C8) bifunctional polymer precursors (e.g., succinic acid, cadaverine, 1,4-butanediol). Less attention has been given to medium-chain (C12-C14) monomers such as omega-hydroxy fatty acids (omega-OHFAs) and alpha,omega-dicarboxylic acids (alpha,omega-DCAs), which are precursors to high performance polyesters and polyamides. Here we engineer a complete microbial conversion of glucose to C12 and C14 omega-OHFAs and alpha,omega-DCAs, with precise control of product chain length. Using an expanded bioinformatics approach, we screen a wide range of enzymes across phyla to identify combinations that yield complete conversion of intermediates to product alpha,omega-DCAs. Finally, through optimization of culture conditions, we enhance production titer of C12 alpha,omega-DCA to nearly 600 mg/L. Our results indicate potential for this microbial factory to enable commercially relevant, renewable production of C12 alpha,omega-DCA a valuable precursor to the high-performance plastic, nylon-6,12.