| 引用本文: | 唐千,薛校风,王惠,邢鹏.湖泊生态系统产甲烷与甲烷氧化微生物研究进展.湖泊科学,2018,30(3):597-610. DOI:10.18307/2018.0302 |
| TANG Qian,XUE Xiaofeng,WANG Hui,XING Peng.New knowledge of methanogens and methanotrophs in lake ecosystems. J. Lake Sci.2018,30(3):597-610. DOI:10.18307/2018.0302 |
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| 摘要: |
| 湖泊生态系统是重要的大气甲烷来源，其甲烷释放量占全球自然生态系统的40%.产甲烷和甲烷氧化微生物在湖泊甲烷生产和消耗过程中发挥关键作用.本文综述了近期有关湖泊生态系统甲烷产生与氧化过程的研究进展，重点介绍产甲烷与甲烷氧化微生物在湖泊中的分布特征、代谢途径以及调控机制.现有研究表明，湖泊中甲烷的生成不仅仅依靠赋存于沉积物和水体厌氧层的产甲烷古菌，还可能来自有氧环境中其他产甲烷微生物的代谢作用.湖泊中的甲烷在脱离水体逸散至大气之前，被甲烷氧化微生物利用，转化成二氧化碳和小分子有机化合物（如甲醇、甲醛和甲酸等）.除了传统依赖氧气作为电子受体的好氧氧化过程外，新近研究还揭示了多种厌氧甲烷氧化过程，包括依赖还原硫酸盐、硝酸盐和亚硝酸盐以及Fe3+/Mn4+等金属离子的甲烷氧化过程.文献综合分析表明，反硝化型厌氧甲烷氧化过程主要发生在淡水湖泊中，而硫酸盐还原型主要发生在高盐度或者高碱度湖泊中.水体温度、溶解氧浓度可以显著影响产甲烷与甲烷氧化微生物的丰度与群落结构，其他湖泊环境条件，如盐度、pH和有机质类型等都可能改变产甲烷与甲烷氧化微生物的分布和代谢活性.不同湖泊类型的比较研究，有助于全面掌握影响湖泊产甲烷与甲烷氧化微生物的时空分布与代谢特征的主导因素. |
| 关键词: 湖泊生态系统 产甲烷菌 甲烷氧化菌 厌氧甲烷氧化菌 影响因子 |
| DOI：10.18307/2018.0302 |
| 分类号: |
| 基金项目:国家自然科学基金项目（31722008，91751111，31370508）、中国科学院青年创新促进会项目（2014273）和湖泊与环境国家重点实验室开放研究基金项目（2012SKL005）联合资助. |
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| New knowledge of methanogens and methanotrophs in lake ecosystems |
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TANG Qian1,2, XUE Xiaofeng1,3, WANG Hui3, XING Peng1
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1.State Key Laboratory of Lake and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P. R. China;2.University of Chinese Academy of Sciences, Beijing 100049, P. R. China;3.College of Life Sciences, Nanjing Normal University, Nanjing 210046, P. R. China
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| Abstract: |
| Inland waters, especially lakes are important methane sources to the atmosphere, which contributed to 40% of the total methane production from the global natural ecosystems. The methanogens and methanotrophs play key roles in the reactions of methane productions and consumptions in lake ecosystems. New discoveries of methane generation and oxidation progress in lake environments have been reviewed in this manuscript, in which the emphasis was put on the distribution, metabolism and regulation of methanogens and methanotrophs in natural lakes. The current researchers found that the methane in lakes is produced not only by the methanogens lived in the sediment and anaerobic water layer, but also by the microbes survived in the aerobic water. Current knowledge was consensus that most of the methane was oxidized by the methane oxidation process and transformed into carbon dioxide, methanol, formaldehyde or formic acid before it escaping from the water. Besides the traditional methane oxidation based on oxygen reduction, anaerobic oxidation of methane (AOM) was the important supplementary process in natural lakes. Researches indicated there were at least three major AOM processes in lakes, which were sulfate-dependent AOM, nitrite-and nitrate-dependent AOM as well as Fe3+/Mn4+-dependent AOM. Niches separations were identified among different AOM processes, for example, the sulfate-dependent AOM were generally detected in the soda and saline lakes, whereas the nitrite-and nitrate-dependent AOM took place in the freshwater lakes. Water temperature and dissolved oxygen were identified to be the most important factors that significantly influencing the abundance of methanogens and methanotrophs, as well as the community composition of these microbes. Actually, microorganisms participated in the methane production and oxidation could be affected by multiple factors in a certain ecosystem, such as pH, organic matter and salinity. More types of lakes need to be studied in order to reveal the pattern of the spatial-temporal distribution of methanogens and methanotrophs and the mechanisms of metabolism regulation. |
| Key words: Lake ecosystem methanogens methanotrophs anaerobic oxidation of methane impact factors |
