Machine learning-aided engineering of hydrolases for PET depolymerization.

Autor: Lu H; McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA., Diaz DJ; Department of Chemistry, The University of Texas at Austin, Austin, TX, USA., Czarnecki NJ; McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA., Zhu C; McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA., Kim W; McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA., Shroff R; Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA.; DEVCOM ARL-South, Austin, TX, USA., Acosta DJ; Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA., Alexander BR; Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA., Cole HO; McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA.; Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA., Zhang Y; Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA., Lynd NA; McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA., Ellington AD; Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA., Alper HS; McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA. halper@che.utexas.edu.
Jazyk: angličtina
Zdroj: Nature [Nature] 2022 Apr; Vol. 604 (7907), pp. 662-667. Date of Electronic Publication: 2022 Apr 27.
DOI: 10.1038/s41586-022-04599-z
Abstrakt: Plastic waste poses an ecological challenge 1-3 and enzymatic degradation offers one, potentially green and scalable, route for polyesters waste recycling 4 . Poly(ethylene terephthalate) (PET) accounts for 12% of global solid waste 5 , and a circular carbon economy for PET is theoretically attainable through rapid enzymatic depolymerization followed by repolymerization or conversion/valorization into other products 6-10 . Application of PET hydrolases, however, has been hampered by their lack of robustness to pH and temperature ranges, slow reaction rates and inability to directly use untreated postconsumer plastics 11 . Here, we use a structure-based, machine learning algorithm to engineer a robust and active PET hydrolase. Our mutant and scaffold combination (FAST-PETase: functional, active, stable and tolerant PETase) contains five mutations compared to wild-type PETase (N233K/R224Q/S121E from prediction and D186H/R280A from scaffold) and shows superior PET-hydrolytic activity relative to both wild-type and engineered alternatives 12 between 30 and 50 °C and a range of pH levels. We demonstrate that untreated, postconsumer-PET from 51 different thermoformed products can all be almost completely degraded by FAST-PETase in 1 week. FAST-PETase can also depolymerize untreated, amorphous portions of a commercial water bottle and an entire thermally pretreated water bottle at 50 ºC. Finally, we demonstrate a closed-loop PET recycling process by using FAST-PETase and resynthesizing PET from the recovered monomers. Collectively, our results demonstrate a viable route for enzymatic plastic recycling at the industrial scale.
(© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)
Databáze: MEDLINE
Externí odkaz: