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 ap-proaches for depolymerizing PET to its corresponding monomers opens up new opportunities for PET upcy-cling 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 mg/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.

Automated summary

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. This study identifies a strain called Rhodococcus jostii PET (RPET) that can directly use PET hydrolysate as a sole carbon source. Through rational metabolic engineering, the production of lycopene from PET is significantly increased.