• Integrating rational design an...

*Result*: Integrating rational design and machine learning to engineer a novel plastic depolymerase to break down PBAT-based mulch film for sustainable recycling.

Title:
Integrating rational design and machine learning to engineer a novel plastic depolymerase to break down PBAT-based mulch film for sustainable recycling.
Authors:
Li X; Xianghu Laboratory, Hangzhou 311231, China; Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, China. Electronic address: lixinjia@zju.edu.cn., Chen W; Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, China; ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Hangzhou, Zhejiang 311200, China., Wang L; Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, China; ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Hangzhou, Zhejiang 311200, China., Zheng P; Xianghu Laboratory, Hangzhou 311231, China., Xu J; Xianghu Laboratory, Hangzhou 311231, China., Tao X; Xianghu Laboratory, Hangzhou 311231, China. Electronic address: taoxiaoyuan@xhlab.ac.cn., Yu H; Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, China; ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Hangzhou, Zhejiang 311200, China. Electronic address: yuhaoran@zju.edu.cn., Xu S; Xianghu Laboratory, Hangzhou 311231, China; Institute of Digital Agriculture, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China. Electronic address: xushengchun@xhlab.ac.cn.
Source:
Journal of hazardous materials [J Hazard Mater] 2025 Dec 05; Vol. 500, pp. 140581. Date of Electronic Publication: 2025 Nov 22.
Publication Type:
Journal Article
Language:
English
Journal Info:
Publisher: Elsevier Country of Publication: Netherlands NLM ID: 9422688 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1873-3336 (Electronic) Linking ISSN: 03043894 NLM ISO Abbreviation: J Hazard Mater Subsets: MEDLINE
Imprint Name(s):
Original Publication: Amsterdam : Elsevier
MeSH Terms:
Polyesters*/metabolism , Polyesters*/chemistry , Phthalic Acids*/metabolism , Phthalic Acids*/chemistry , Carboxylic Ester Hydrolases*/metabolism , Carboxylic Ester Hydrolases*/chemistry , Carboxylic Ester Hydrolases*/genetics , Recycling* , Machine Learning*, Thermobifida/enzymology ; Biodegradation, Environmental
Contributed Indexing:
Keywords: Machine learning; Plastic degradation; Rational design; ThPETase
Substance Nomenclature:
0 (Polyesters)
0 (Phthalic Acids)
0 (poly(butylene adipate-co-butylene terephthalate))
EC 3.1.1.- (Carboxylic Ester Hydrolases)
Entry Date(s):
Date Created: 20251126 Date Completed: 20251210 Latest Revision: 20251210
Update Code:
20260130
DOI:
10.1016/j.jhazmat.2025.140581
PMID:
41297265
Database:
MEDLINE

*Further Information*

*Biodegradable polybutylene adipate terephthalate (PBAT) represents a promising alternative to conventional polyolefins and has gained widespread adoption in packaging, agricultural mulch films, and diverse industrial applications. Despite its biodegradable classification, PBAT's intrinsically low biodegradation efficiency in natural environments caused persistent ecological contamination. A critical challenge in addressing this problem remains the development of efficient PBAT-degrading enzymes with broad thermal adaptability. In this study, we identified a new PET hydrolase (ThPETase) from Thermobifida halotolerans via consensus sequence analysis and subsequently engineered it through structure- and surface charge-guided design, integrating the machine learning model EvolvePro. The optimized variant, DCTPC_4M_S122H (ThPETase_N48D/D204C/L213T/S214P/D253C/S68K/D105R /G194Q/D232K/S122H) showed a remarkable 33.9°C increase in melting temperature (T<subscript>m</subscript>) compared to the wild-type enzyme, and demonstrated an enhanced hydrolytic activity against PBAT powders across a broad temperature range (37-70°C), achieving up to a 91-fold improvement in PBAT degradation efficiency at 37°C. Notably, it efficiently degraded PBAT-based mulch films within 20 h at 37°C, 8 h at 50°C, and merely 6 h at 60°C, significantly outperforming previously reported enzymes. The enzymatic degradation yielded high-purity terephthalic acid (≥99 %), which can be directly reclaimed as a feedstock for PET and PBAT synthesis. This enables a closed-loop recycling system for sustainable plastic waste management.
(Copyright © 2025 Elsevier B.V. All rights reserved.)*

*Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this manuscript.*