水生生态系统中金属依赖型甲烷厌氧氧化过程的研究进展

甲烷是一种比CO_2更活跃的温室气体,微生物驱动的甲烷厌氧氧化(anaerobicoxidationof methane,AOM)过程对于降低全球甲烷的排放有着重要意义。参与AOM反应的最终电子受体主要分为三类,即硫酸盐、亚硝酸盐/硝酸盐以及以Fe(III)、Mn(IV)等为代表的金属离子。可溶性金属物质和不溶性金属矿物都可以被用作AOM的电子受体,这大大提高了参与金属依赖型甲烷厌氧氧化(metal-dependent anaerobic oxidation of methane,Metal-AOM)微生物的生态价值。目前研究聚焦在功能菌群、生态分布等方面。部分甲烷厌氧氧化古菌(anaerobic methanotrophic archaea,ANME)具有直接或间接参与Metal-AOM过程的能力。但由于功能菌群纯化富集和分离具有一定难度,有关其生理生化和生态学等特征的研究受到限制。同时,随着Metal-AOM被发现存在于不同水生生境中,其在污染治理领域的应用也被广泛讨论,但是河口生境尚缺乏深入研究。本文从Metal-AOM的发现入手,阐述了参与该过程的主要微生物及其在水域环境下的生态分布,并介绍了Metal-AOM的反应机制和在实际应用中的机遇与挑战。最后,根据现有研究结果,提出对功能菌群、机制及环保应用的研究展望,包括微生物分离纯化和影响因素、菌群代谢活性和作用机制的解析以及新型生产工艺的设计和发展应用,以期为今后的环境污染治理和工业应用提供借鉴意义。

Metal-dependent anaerobic oxidation of methane in aquatic ecosystems: a review

Methane is a more active greenhouse gas than CO2, and the process of methane anaerobic oxidation (AOM) driven by microorganisms is of great significance in reducing global methane emissions. The final electron acceptors involved in AOM reaction are mainly divided into three categories: sulfate, nitrite/nitrate, and metal ions represented by Fe(III), Mn(IV), etc. Both soluble metal substances and insoluble metal minerals can be used as electron acceptors for AOM, which greatly enhances the ecological value of microorganisms participating in metal-dependent anaerobic oxidation of methane (Metal-AOM). The current research focuses on functional flora, ecological distribution, etc. Some anaerobic methanotrophic archaea (ANME) have the ability to participate in Metal-AOM process directly or indirectly. However, due to the difficulty in purification, enrichment and isolation of functional microorganisms, the study on their physiological, biochemical and ecological characteristics has been limited. Meanwhile, with the discovery of Metal-AOM in different aquatic habitats, its application in the field of pollution control has been widely discussed; but there is a lack of in-depth research of estuarine habitats. Based on the discovery of Metal-AOM, the main microorganisms involved in the process and their ecological distribution in the aquatic environment were described, and the reaction mechanism of Metal-AOM and its opportunities and challenges in practical application were introduced. Finally, based on the existing research results, this paper puts forward the research prospects of functional microflora, mechanisms and environmental applications, including the isolation and purification of microorganisms, the analysis of their metabolic activity and mechanism of action, as well as the design, development and application of new production techniques, in order to provide reference for environmental pollution control and industrial applications in the future.