A New PETase from the Human Saliva Metagenome and Its Functional Modification via Genetic Code Expansion in Bacteria

The discovery and engineering of new plastic degrading enzymes is an important challenge in chemical biotechnology to enable transition to a more sustainable and circular plastics economy. This field has so far yielded a range of enzymes and microbial pathways for the recycling and valorization of plastic waste. New research from Uttamapinant et al. reports the discovery of a novel polyethylene terephthalate (PET) hydrolase from the human saliva metagenome that displays improved properties and catalytic performance over previously characterized PET hydrolases (PETases). The authors also demonstrate the site-specific incorporation of a photocaged unnatural amino acid, 2,3-diaminopropionic acid (DAP), which upon photodecaging enables covalent binding of DAP to the PET surface. Thus, this work highlights metagenomic datasets as an untapped source of new PET degrading enzymes and the chemical modification of PETases via genetic code expansion, enabling new biotechnologies for the circular plastics economy.

Automated summary

The discovery and engineering of new plastic degrading enzymes is crucial for the transition to a more sustainable and circular plastics economy. Recent research has reported the discovery of a novel PET hydrolase from human saliva metagenome, which shows improved properties and performance over previous PETases. The study also demonstrates the incorporation of a photocaged unnatural amino acid, enabling covalent binding to the PET surface, highlighting the potential of metagenomic datasets and genetic code expansion for new biotechnologies in the circular plastics economy.