地学前缘 ›› 2025, Vol. 32 ›› Issue (3): 248-262.DOI: 10.13745/j.esf.sf.2025.3.45

• 地球系统过程与生态环境效应 • 上一篇    下一篇

环境中微塑料的微生物降解机制与生物强化

丁佳妍(), 刘翔宇, 陈旭文, 汤磊, 高彦征*()   

  1. 南京农业大学 土壤有机污染控制与修复研究所, 江苏 南京 210095
  • 收稿日期:2025-02-07 修回日期:2025-02-26 出版日期:2025-03-25 发布日期:2025-04-20
  • 通信作者: *高彦征(1975—),男,博士,教授,博士生导师,主要从事土壤环境学领域研究。E-mail:gaoyanzheng@njau.edu.cn
  • 作者简介:丁佳妍(2001—),女,硕士研究生,主要从事土壤环境中有机污染物环境行为与效应研究。E-mail:dingjiayan@stu.njau.edu.cn
  • 基金资助:
    国家重点研发计划政府间科技合作项目(2023YFE0110800);国家自然科学基金项目(42430703)

Biodegradation mechanisms and biological enhancement of microplastics in the environment

DING Jiayan(), LIU Xiangyu, CHEN Xuwen, TANG Lei, GAO Yanzheng*()   

  1. Institute of Organic Contaminant Control and Soil Remediation, Nanjing Agricultural University, Nanjing 210095, China
  • Received:2025-02-07 Revised:2025-02-26 Online:2025-03-25 Published:2025-04-20

摘要:

作为一类新污染物,环境中微塑料威胁生态安全和人类健康。微生物降解技术因其经济高效、环境友好的特质而备受关注。近些年来,生物膜、酶工程、基因调控等技术在微塑料微生物降解研究中取得重要进展。生物膜降解微塑料的过程通常包括改变表面特性、浸出添加剂、酶或自由基攻击、渗透分解等阶段。细胞外酶可裂解微塑料的大分子结构,细胞内酶则可改变底物结构并处理代谢产物,两者协同作用构建高效酶系统已成为当前研究的重点之一。基于基因工程技术,以往已培育了多种工程菌株,通过生物信息学挖掘功能基因、解析代谢途径,并结合宏基因组修饰技术,显著提升了微塑料的降解效率。本文综述了微生物降解微塑料的最新研究进展,剖析了微塑料降解功能微生物的物种多样性、降解代谢途径及其机制等。已有研究表明,细菌、真菌和微藻等多种微生物皆具备降解微塑料的能力,其中复合菌群的协同作用尤为显著。细菌主要通过分泌水解酶和氧化酶,切断大分子链或改变塑料化学结构来降解微塑料;真菌则依靠分泌细胞内、外酶及生物表面活性剂,将微塑料分解为单体,菌丝还能增强作用效果;微藻可借助光合作用,分泌毒素、酶以及胞外聚合物促进降解。微塑料的降解通常经历生物劣化、碎片化、同化及矿化四个阶段,不同微生物对聚乙烯、聚苯乙烯等各类微塑料降解效率及机制存在差异。本综述为深入探究微塑料微生物降解原理、进一步发展微生物降解微塑料的方法和技术提供了依据。

关键词: 微塑料, 微生物降解, 代谢途径, 降解机制

Abstract:

As a type of emerging pollutants, microplastics have become pervasive contaminants affecting ecosystem safety and human health. Microbial biodegradation of microplastics has attracted significant attention due to its environmentally friendly and sustainable attributes. Recent advancements have been achieved in the microbial biodegradation of pollutants through biofilms, enzyme engineering, and gene regulation. Biofilms influence the microplastics degradation by altering surface properties, leaching additives, enzyme or radical attacks, and permeation decomposition. Extracellular enzymes cleave the macromolecular structures, while intracellular enzymes modify substrate structures and process metabolites. Current research focuses on constructing highly efficient enzyme systems. Genetic engineering has enabled the cultivation of engineered bacteria, while bioinformatics aids in identifying functional genes and elucidating the degradation pathways. Metagenomic modification has been used to enhance biodegradation efficiency. This article reviews recent progress in microbial biodegradation of microplastics, encompassing diverse degrading microorganisms, clear degradation metabolic pathways and mechanisms. Multiple microorganisms including bacteria, fungi, and microalgae possess degradation capabilities. Composite microbial consortia synergistically drive the degradation process. Bacteria mainly degrade microplastics by secreting hydrolases and oxidases, which can break the macromolecular chains or change the chemical structure of plastics. Fungi, on the other hand, rely on the secretion of intracellular and extracellular enzymes as well as biological surfactants to break down microplastics into monomers. The mycelium can also enhance the degradation effect. Microalgae can promote degradation by means of photosynthesis, secreting toxins, enzymes, and extracellular polymeric substances. Microplastic degradation typically occurs in four stages: bio-deterioration, fragmentation, assimilation, and mineralization. Different microorganisms exhibit varying efficiencies and mechanisms for microplastics degradation such as polyethylene and polystyrene. By summarizing current research findings, this review provides a theoretical foundation for further in-depth exploration of microbial biodegradation mechanisms and offers potential methods and techniques for eliminating the microplastics in the environment.

Key words: microplastics, microbial biodegradation, metabolic pathways, degradation mechanisms

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