Plastic-degrading enzymes hold immense potential for eco-friendly recycling methods. However, the catalytic rates of current enzymes do not stack up against the mammoth task of degrading millions of tons of plastic waste per year. In the quest for more efficient polyethylene terephthalate (PET)-degrading enzymes, Zhang et al. report the discovery and characterization of PET40, a versatile PET-hydrolyzing esterase that is divergent from most characterized PETases. While PET40 has comparably low hydrolytic activity on PET, Zhang et al. demonstrate its broad activity on an expanded substrate pool. This sheds light on the potential ecological role of these esterases and suggests that PET might be only a recent addition to their substrate spectrum.
Keywords: biodegradation; hydrolases; metagenome; plastic pollution; polyethylene terephthalate; promiscuity.
© 2023 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.