pubs.acs.org
Heterologous Rieske Nonheme Iron Monooxygenases Enable Efficient Microbial Conversion of Lignin Guaiacol to Adipic Acid
Adipic acid (1,6-hexanedioic acid) is a key building block for nylon-6,6, a widely used polymer in the global chemical industry. Current industrial production relies on petrochemical feedstocks and nitric acid oxidation of cyclohexane/cyclohexanol mixtures, releasing nitrous oxide, a potent greenhouse gas. Biotechnological routes offer sustainable alternatives but have been limited by low yields or reliance on multistrain systems. Here we report a one-pot, single-strain microbial process for the efficient conversion of guaiacol─a lignin-derived aromatic─into adipic acid. By integrating heterologous Rieske nonheme iron monooxygenases from Cupriavidus necator N-1 with systematic process optimizations in engineered Escherichia coli, we achieve near-quantitative conversion with 97% yield and titers of 1.5 g/L in aqueous, lab-scale reactions. This work demonstrates a novel and efficient strategy for lignin valorization through engineered microbial synthesis, providing a new sustainable and scalable route to adipic acid.
