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Luwen WANG Jiwen GE Liang FENG Yaoyao LIU Yu LI Jiumei WANG Xiang XIAO Zhiqi ZHANG 《大气科学进展》2022,39(8):1375-1385
Wetland ecosystems are the most important natural methane (CH4) sources, whose fluxes periodically fluctuate. Methanogens (methane producers) and methanotrophs (methane consumers) are considered key factors affecting CH4 fluxes in wetlands. However, the symbiotic relationship between methanogens and methanotrophs remains unclear. To help close this research gap, we collected and analyzed samples from four soil depths in the Dajiuhu subalpine peatland in January, April, July, and October 2019 and acquired seasonal methane flux data from an eddy covariance (EC) system, and investigated relationships. A phylogenetic molecular ecological networks (pMENs) analysis was used to identify keystone species and the seasonal variations of the co-occurrence patterns of methanogenic and methanotrophic communities. The results indicate that the seasonal variations of the interactions between methanogenic and methanotrophic communities contributed to CH4 emissions in wetlands. The keystone species discerned by the network analysis also showed their importance in mediating CH4 fluxes. Methane (CH4) emissions in wetlands were lowest in spring; during this period, the most complex interactions between microbes were observed, with intense competition among methanogens while methanotrophs demonstrated better cooperation. Reverse patterns manifested themselves in summer when the highest CH4 flux was observed. Methanoregula formicica was negatively correlated with CH4 fluxes and occupied the largest ecological niches in the spring network. In contrast, both Methanocella arvoryzae and Methylocystaceae demonstrated positive correlations with CH4 fluxes and were better adapted to the microbial community in the summer. In addition, soil temperature and nitrogen were regarded as significant environmental factors to CH4 fluxes. This study was successful in explaining the seasonal patterns and microbial driving mechanisms of CH4 emissions in wetlands. 相似文献
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Jing Li Chang-ling Liu Neng-you Wu Xiao-qing Xu Gao-wei Hu Yan-long Li Qing-guo Meng 《China Geology》2022,5(2):285-292
Large amounts of gas hydrate are distributed in the northern slope of the South China Sea, which is a potential threat of methane leakage. Aerobic methane oxidation by methanotrophs, significant methane biotransformation that occurs in sediment surface and water column, can effectively reduce atmospheric emission of hydrate-decomposed methane. To identify active aerobic methanotrophs and their methane oxidation potential in sediments from the Shenhu Area in the South China Sea, multi-day enrichment incubations were conducted in this study. The results show that the methane oxidation rates in the studied sediments were 2.03–2.36 μmol/gdw/d, which were higher than those obtained by sediment incubations from other areas in marine ecosystems. Thus the authors suspect that the methane oxidation potential of methanotrophs was relatively higher in sediments from the Shenhu Area. After the incubations family Methylococcaea (type I methanotrophs) mainly consisted of genus Methylobacter and Methylococcaea_Other were predominant with an increased proportion of 70.3%, whereas Methylocaldum decreased simultaneously in the incubated sediments. Collectively, this study may help to gain a better understanding of the methane biotransformation in the Shenhu Area.©2022 China Geology Editorial Office. 相似文献
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微生物介导的土壤甲烷循环及全球变化研究 总被引：9，自引：0，他引：9
甲烷是主要的温室气体之一, 目前在大气中的含量达1.7×10-6m3·m-3, 比工业革命前增加了115%, 并以1%年增长速度稳定增长. 甲烷吸收太阳远红外光的能力比CO2高20～30倍, 对全球增温的贡献率达15%. 多年来对大气甲烷的产生、转运和循环以及调控的研究表明, 80%以上的甲烷是通过微生物的活动产生的, 一部分在进入大气前被微生物吸收利用, 这样, 大气中甲烷的净含量绝大部分是甲烷产生微生物和甲烷营养微生物相互作用的结果. 因此, 研究甲烷产生菌和甲烷氧化菌的活动规律和生态学特征, 有利于揭示微生物介导的甲烷循环过程, 并探索减排的措施. 已知有80多种甲烷产生菌和100余种甲烷氧化菌, 它们的种类和生态多样性比较广泛, 环境差异和波动影响它们的生理代谢活性, 从而导致甲烷排放的波动性和不确定性. 在未来全球变化条件下, 天然湿地作为重要的甲烷源之一, 如何响应和反馈环境的变化是研究的重点领域. 相似文献
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草海是由喀斯特盆地积水发育而形成的一个完整的、典型的高原湖泊湿地生态系统,同时也是中国面积最大的岩溶构造湖.甲烷氧化菌作为一类能够将甲烷氧化为CO2和水的独特微生物,其活动与生态系统中能量流动和元素循环的关键步骤密不可分.为了解贵州草海喀斯特高原湖泊湿地中甲烷氧化菌的群落结构特征及功能,利用宏基因组技术对浅水沼泽、莎草湿地、深水沉积物进行研究.结果表明,草海湿地中主要的好氧甲烷氧化菌为Methylobacter和Methylomonas,主要的厌氧甲烷氧化菌为Candidatus_Methylomirabilis_oxyfera,属于NC10门的反硝化型厌氧甲烷氧化菌.所研究的4种代谢功能基因种类多样性表现为碳代谢＞氮代谢＞硫代谢＞甲烷代谢;基于KEGG数据库共注释到6大类功能和18条与碳、甲烷、氮、硫相关的完整代谢路径.PCoA分析表明浅水沼泽和莎草湿地中甲烷氧化菌的种类和功能相似,且与深水沉积物存在差异.物种与功能相关性网络分析结果显示Methylacidiphilum_fumariolicum和Methylacidiphilum_kamchatkense与草海湖泊湿地中的各个代谢功能均具有较强的相关性.显著影响草海湿地中大多数甲烷氧化菌的群落结构的环境因素是硝酸盐、电导率、总磷和有机质. 相似文献
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湖泊生态系统产甲烷与甲烷氧化微生物研究进展 总被引：3，自引：1，他引：2
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Fe~(3+)/Mn~(4+)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. 相似文献
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Methanotrophic biomass and community structure were assessed for a soil column enriched with natural gas. An increase in microbial biomass, based on phospholipid ester-linked fatty acids (PLFA), was apparent for the natural gas-enriched column relative to a control column and untreated surface soil. Following GC-MS analyses of the derivatized monounsaturated fatty acids, the major component (22% of the PLFA) of the natural gas-enriched column was identified as 18·1Δ 10c. This relatively novel fatty acid has only been previously reported as a major component in methanotrophs. Its presence in the soil, together with other supportive evidence, implies that this microbial metabolic group makes a large contribution to the column flora. Other microbial groups were also recognized and differences compared between the soils analysed. A recently developed HPLC method for the separation and characterisation of archaebacterial phospholipid-derived signature di- and tetra-ether lipids was used to examine methane-producing digesters. With this technique, methanogenic biomasses of approximately 1011 bacteria per g dry weight of digestor material were determined. Differences between ratios of diether to tetraether phospholipids were apparent for the digestors analysed, though the causes are at this stage unknown. Taken together, these two methods can be used to estimate methanotrophic and methanogenic contributions in both model systems and environmental samples. 相似文献
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