Towards bio-upcycling of polyethylene terephthalate

Over 359 million tons of plastics were produced worldwide in 2018, with significant growth expected the near future, resulting global challenge end-of-life management. The recent identification enzymes that degrade previously considered non-biodegradable opens up opportunities to steer plastic recycling industry into realm biotechnology. Here, sequential conversion post-consumer polyethylene terephthalate (PET) two types bioplastics is presented: a medium chain-length polyhydroxyalkanoate (PHA) and novel bio-based poly(amide urethane) (bio-PU). PET films are hydrolyzed by thermostable polyester hydrolase yielding highly pure ethylene glycol. obtained hydrolysate used directly as feedstock for terephthalate-degrading Pseudomonas umsongensis GO16, also evolved efficiently metabolize glycol, produce PHA. strain further modified secrete hydroxyalkanoyloxy-alkanoates (HAAs), which monomers chemo-catalytic synthesis bio-PU. In short, value-chain upcycling shown circumvents costly purification monomers, adding technological flexibility management plastics.