Poly(ethylene terephthalate) catalytic recycling process based on Vibrio natriegens formate metabolism

The increasing accumulation of waste poly(ethylene terephthalate) (PET) poses a significant threat to the ecological environment. Although current recycling technologies offer promising solutions, their widespread implementation is hindered by high costs, intensive energy consumption, and low efficiency. To address these challenges, we developed a catalytic system that integrated glycolysis electroconversion, and enzymatic hydrolysis, achieving a synergistic treatment of efficient PET conversion and the valorization of formate-containing wastewater. In this system, PET was efficiently depolymerized via KHCO 3 -catalyzed glycolysis, resulting in a total yield of 96.5% of bis(2-hydroxyethyl) terephthalate (BHET) and mono(2-hydroxyethyl) terephthalate (MHET). The ethylene glycol (EG) was further electrooxidized to formate using a Co, Cl-NiS catalyst, achieving high faradic efficiency (>90%) and formate yield (>80%). Then, this resulting formate served as an effective carbon source for cultivating Vibrio natriegens under non-sterile conditions to produce FAST-PETase and KL-MHETase. The crude enzyme extracts could efficiently catalyze the hydrolysis of 150   g/L crude BHET mixture. In summary, this study establishes an integrated catalytic platform that synergizes chemical, electrochemical, and biological processes. This presents a novel and sustainable pathway for closed-loop recycling of waste PET.