Denitrifying Anaerobic Methane Oxidation: A Previously Overlooked Methane Sink in Intertidal Zone
Denitrifying Anaerobic Methane Oxidation: A Previously Overlooked Methane Sink in Intertidal Zone
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反硝化厌氧甲烷氧化：以前被忽视的潮间带甲烷汇
DOI：
10.1021/acs.est.8b05742
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发表时间：
2019
影响因子：
11.4
通讯作者：
Hu Baolon
中科院分区：
文献类型：
--
作者：
Wang Jiaqi;Cai Chaoyang;Li Yufen;Hua Miaolian;Wang Junren;Yang Hongrui;Zheng Ping;Hu Baolon
潮间带是一个富含有机质的开放生态系统，在全球生物地球化学循环中发挥着重要作用。此前认为海洋生态系统中甲烷主要通过硫酸盐依赖的厌氧甲烷氧化（硫酸盐-AOM）过程去除，而忽略了其他厌氧甲烷氧化过程。最近的研究表明，反硝化厌氧甲烷氧化（DAMO），包括亚硝酸盐依赖性厌氧甲烷氧化（亚硝酸盐-AOM）和硝酸盐依赖性厌氧甲烷氧化（硝酸盐-AOM），也可以氧化甲烷。本工作通过高通量测序、qPCR和稳定同位素示踪方法对潮间带DAMO古菌和细菌的群落结构、数量和潜在甲烷氧化率进行了研究。结果表明，硝酸盐-AOM 和亚硝酸盐-AOM 在潮间带均很活跃，并显示出近似的甲烷氧化速率。 DAMO古菌和DAMO细菌的16S rRNA基因拷贝数为104∼105copies g–1(干沉积物)，而NC10细菌略高。 DAMO过程对潮间带厌氧甲烷总去除量的贡献率达到65.6%～100%，表明DAMO过程是潮间带生态系统重要的甲烷汇。实验室培养还表明，DAMO古菌对氧气更敏感，更喜欢缺氧的环境。这些结果帮助我们更全面地了解自然栖息地中的甲烷和氮循环。
The intertidal zone is an open ecosystem rich in organic matter and plays an important role in global biogeochemical cycles. It was previously considered that methane was mainly removed by sulfate-dependent anaerobic methane oxidation (sulfate–AOM) process in marine ecosystems while other anaerobic methane oxidation processes were ignored. Recent researches have demonstrated that denitrifying anaerobic methane oxidation (DAMO), consisting of nitrite-dependent anaerobic methane oxidation (nitrite–AOM) and nitrate-dependent anaerobic methane oxidation (nitrate–AOM), can also oxidize methane. In this work, the community structure, quantity and potential methane oxidizing rate of DAMO archaea and bacteria in the intertidal zone were studied by high-throughput sequencing, qPCR and stable isotope tracing method. The results showed that nitrate–AOM and nitrite–AOM were both active in the intertidal zone and showed approximate methane oxidation rates. The copy number of 16S rRNA gene of DAMO archaea and DAMO bacteria were 104∼ 105copies g–1(dry sediment), whereas NC10 bacteria were slightly higher. The contribution rate of DAMO process to total anaerobic methane removal in the intertidal zone reached 65.6% ∼ 100%, which indicates that DAMO process is an important methane sink in intertidal ecosystem. Laboratory incubations also indicated that DAMO archaea were more sensitive to oxygen and preferred a more anoxic environment. These results help us draw a more complete picture of methane and nitrogen cycles in natural habitats.