塑料降解酶的催化机理及应用研究进展

Catalytic mechanisms and applications of plastic-degrading enzymes: a review

摘要:

近年来，塑料污染问题日益严峻，酶介导的塑料降解技术备受关注。大量研究从典型生境、极端环境、宿主中筛选到多种塑料降解酶。然而，较短的共进化周期导致微生物难以进化出特异性塑料降解酶。现有的塑料降解酶主要分布在碳水化合物酯酶(carbohydrate esterases, CEs)和辅助活性酶(auxiliary activities, AAs)家族，这些蛋白被证实与木质素降解有关。因此，木质素降解酶系也成为塑料降解酶的潜在来源。目前塑料降解酶的催化机制与应用相关研究仍然聚焦于IsPETase和叶枝堆肥角质酶(leaf-branch compost cutinase, LCC)，而对非水解型塑料降解酶的类型及结构特征缺乏系统认知。本文综述了C-O与C-C骨架型塑料降解酶的研究现状和催化机理，阐述了近5年塑料降解酶在筛选策略、工程化改造及其应用方面的研究进展，旨在推动降解酶研究在机制和应用转化方面的协同发展，为解决塑料污染治理提供理论依据。

Abstract:

Enzyme-mediated degradation of plastics is considered as a promising solution for addressing escalating plastic pollution. Extensive studies have identified diverse plastic-degrading enzymes from typical habitats, extreme environments, and different hosts. However, the short co-evolution period between microbes and plastics limits the natural evolution of specific plastic-degrading enzymes. The identified plastic-degrading enzymes mainly belong to the carbohydrate esterase (CE) and auxiliary activity (AA) enzyme families, being involved in lignin degradation. Consequently, lignin degradation-related enzymes represent a promising resource for the discovery of novel plastic-degrading enzymes. The available studies on the catalytic mechanisms and applications of plastic-degrading enzymes mainly focused on IsPETase and leaf-branch compost cutinase (LCC). Systematic insights into non-hydrolytic plastic-degrading enzymes remain scarce. This review summarizes the types and catalytic mechanisms of plastic-degrading enzymes related to C-O and C-C backbone plastics, and advancements in their screening strategies, engineering modifications, and applications over the past five years. These findings contribute to the collaborative evolution of enzyme research in terms of mechanisms and application innovation. Furthermore, this review establishes a theoretical framework for plastic pollution control.