De Novo Production of 1,6-Hexanediol and 1,6-Hexamethylenediamine from Glucose by Metabolic Engineered Escherichia coli

1,6-Hexamethylenediamine (HMD) and 1,6-hexanediol (HDO) are pivotal C6 platform chemicals with extensive applications as key monomers in the synthesis of nylons, polyurethanes, and polyesters. The biological production of HMD and HDO from cheap and renewable bioresources represents an environmentally benign strategy for the sustainable chemical industry. Herein, we report the development of a novel biocatalytic route for the direct conversion of d-glucose to HMD and HDO in Escherichia coli. This was achieved through the integration of an adipic acid synthesis module with conversion modules tailored for HMD and HDO production. The study entailed a comprehensive optimization of pathway enzymes, protein expression, and precursor supply. Furthermore, a co-culture fermentation strategy was employed to enhance the efficiency of labor division, resulting in a two-strain cocultivation process that yielded 16.62 mg/L of HMD and 214.93 mg/L of HDO using glucose as the sole carbon source. This study establishes a foundational framework for the advancement of sustainable biological production processes for HMD and HDO from renewable resources.