Plastic-degrading enzymes: Advances, challenges, and industrial prospects in enzyme engineering and computational design

Abstract

The accumulation of plastic waste is causing fatal environmental problems that threaten human health. The environmental threat posed by plastics stems from their persistence, potential for bioaccumulation, and inability to degrade via conventional waste disposal methods or physicochemical processes. As a promising alternative, enzyme-based degradation is a practical solution owing to the highly efficient and specific catalytic capacity of enzymes to depolymerize plastic polymers into non-toxic and reusable by-products. Techniques such as enzyme engineering and elucidation of biochemical pathways have led to the identification and optimization of plastic-degrading enzymes (e.g., PETase, MHETase, and cutinases) capable of hydrolyzing recalcitrant polymers (e.g., polyethylene terephthalate (PET), polyethylene (PE), and polypropylene (PP)) under specific environmental conditions. Further advances in modern techniques, such as rational design, directed evolution, metagenomics, and synthetic biology pathways, have increased enzyme stability, activity, and substrate affinity to improve plastic degradation efficiency. Researchers are also exploring the use of microbial consortia and multi-enzyme cocktail formulations to optimize the synergism of plastic bioremediation. Computational methods and artificial intelligence (AI) serve as ideal platforms for predicting enzyme-substrate interactions, site-specific mutagenesis, and accelerating the process of discovering new biocatalysts. Recent advances in protein engineering, synthetic biology, and AI-assisted enzyme design have substantially improved catalytic efficiency, thermostability, and plastic depolymerization performance, accelerating the development of next-generation biocatalysts for plastic waste remediation. Together, these innovations represent a sustainable and scalable solution for plastic pollution, potentially driving a circular plastic economy. This review highlights the interdisciplinary approaches and outlook of the current status of enzyme-mediated plastic degradation technologies.