摘要
我国有机污染废水排放总量巨大,其释放到生态环境中对野生动物和人群健康构成严重威胁。目前,生物修复技术因其绿色环保、经济高效而备受关注。漆酶能够催化不同类型有机污染物的氧化耦合和分解,该反应具有催化速率高、简单可控、底物广谱和生态友好等特点。鉴于游离态漆酶性能不稳定且难以回收利用,而酶固定化技术可显著改善游离态漆酶的稳定性、增加其循环利用次数和催化功效,有望实现漆酶在环境生物修复中的大规模应用。综述了真菌漆酶的分子结构、底物谱和催化性能,对比了漆酶的4种常规固定化方法(吸附、包埋、共价结合和交联)的优缺点。重点总结了固定化漆酶介导雌激素、抗生素、多环芳烃、个人护理产品、合成染料和磺胺类药物等有毒有害污染物的自由基耦合和氧化分解机理。固定化漆酶以分子氧作为电子受体,催化有机污染物氧化生成活性自由基或醌类中间体。这些活性中间体既能以共价耦合的途径形成聚合物,也可通过自由基相互攻击形成分解产物,进而显著降低母体化合物的生态毒性。固定化漆酶在净化有机废水、消除环境污染和维持生态健康等方面已表现出巨大的应用潜力,未来需要进一步筛选廉价固定化载体和提高固定化漆酶循环利用效率。
The total discharged amount of organic wastewater in China is huge,and its release into the ecological environments causes a serious threat to the health of wild animals and humans.Bioremediation technology attracts much concerns because it is green,economic and efficient.Laccase catalyzes the oxidative coupling and decomposition of varied organic pollutants in water and this reaction has several advantages such as simple operation,controllable condition,high catalytic efficiency,broad substrate spectrum,and environmental friendliness.Free laccase is unstable and difficult to be recycled,while immobilization technology can improve the catalytic efficiency,operational stability,and reusability of enzyme.Thus,it is expected to have the large-scale applications of laccase in the environmental bioremediation.This paper reviews the molecular structure,substrate spectrum,and catalytic properties of fungal laccase,clarifies the advantages and disadvantages of four conventional immobilization approaches of laccase such as adsorption,entrapment,covalent bonding,and cross-linking.Further this paper emphatically summarizes the radical coupling and oxidative decomposition mechanisms of immobilized laccase-mediated estrogens,antibiotics,polycyclic aromatic hydrocarbons,personal care products,synthetic dye,and sulfa drugs.Immobilized laccase catalyzes the oxidation of organic contaminants to radical and/or quinone intermediates only using molecular oxygen as an electron acceptor.These reactive intermediates not only can covalently couple to form oligomers and polymers,but yield decomposition products by radical-initiated attack each other,thereby reducing the bioavailability and biotoxicity of the parent compounds.Immobilized laccase shows a huge potential in the purification of organic wastewater,elimination of environmental pollution,and maintenance of ecological health.However,it is necessary to further screen the inexpensive immobilized carriers and improve the recycling rate of immobilized laccase.
作者
陈明雨
倪烜
司友斌
孙凯
CHEN Ming-yu;NI Xuan;SI You-bin;SUN Kai(Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention,School of Resources and Environment,Anhui Agricultural University,Hefei 230036)
出处
《生物技术通报》
CAS
CSCD
北大核心
2021年第6期244-258,共15页
Biotechnology Bulletin
基金
国家自然科学基金项目(41907314)
安徽省自然科学基金项目(1808085QD104)。
关键词
固定化漆酶
催化机理
有机污染
环境修复
immobilized laccase
catalytic mechanism
organic contamination
environmental remediation
