Upcycling of poly(ethylene terephthalate) to produce high-value bio-products

More than 70 million tons of poly(ethylene terephthalate) (PET) are manufactured worldwide every year. The accumulation of PET waste has become a global pollution concern, motivating the urgent development of technologies to valorize post-consumer PET. The development of chemocatalytic and enzymatic approaches for depolymerizing PET to its corresponding monomers opens up new opportunities for PET upcycling through biological transformation. Here, we identify Rhodococcus jostii strain PET (RPET) that can directly use PET hydrolysate as a sole carbon source. We also investigate the potential of RPET to upcycle PET into value-added chemicals, using lycopene as a proof-of-concept product. Through rational metabolic engineering, we improve lycopene production by more than 500-fold over that of the wild type. In addition, we demonstrate the production of approximately 1,300 μg/L lycopene from PET by cascading this strain with PET alkaline hydrolysis. This work highlights the great potential of biological conversion as a means of achieving PET upcycling. [Display omitted] •Found a bacterium that uses terephthalate and ethylene glycol as sole carbon sources•Developed a chemical process to convert poly(ethylene terephthalate) to its monomers•Showed that PET hydrolysate supports bacterium growth despite the high osmolarity•Demonstrated the bioproduction of 1.3 mg/L lycopene from PET hydrolysate The accumulation of waste plastics in the environment has been considered one of the most challenging global issues. Here, Diao et al. describe the development of a chemical-biological hybrid method for upcycling poly(ethylene terephthalate) (PET), laying the foundation for a system to convert plastic waste into high-value chemicals.