Evidence for the Cooccurrence of Nitrite-Dependent Anaerobic Ammonium and Methane Oxidation Processes in a Flooded Paddy Field
Evidence for the Cooccurrence of Nitrite-Dependent Anaerobic Ammonium and Methane Oxidation Processes in a Flooded Paddy Field
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水淹稻田中亚硝酸盐依赖的厌氧铵和甲烷氧化过程同时发生的证据
DOI：
10.1128/aem.02379-14
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发表时间：
2014-12-01
影响因子：
4.4
通讯作者：
Hu, Bao-lan
中科院分区：
文献类型：
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作者：
Shen, Li-dong;Liu, Shuai;Hu, Bao-lan
厌氧氨氧化（anammox）和亚硝酸盐依赖的厌氧甲烷氧化（n-damo）是微生物氮循环中最新发现的两个过程。在本研究中，我们提供了直接证据的anammox和n-damo过程的共同发生在中国东南部的一个淹水稻田。稳定同位素实验表明，在不同土层中，潜在的厌氧氨氧化速率范围为5.6至22.7 nmol N2 g−1（干重）天−1，潜在的n-damo速率范围为0.2至2.1 nmol CO2 g−1（干重）天−1。定量PCR结果表明，不同土层中厌氧氨氧化细菌的丰度范围为1.0 × 105 ~ 2.0 × 106 copies g−1（干重），而n-damo细菌的丰度范围为3.8 × 105 ~ 6.1 × 106 copies g−1（干重）。系统发育分析表明，土样中存在着与“Bundatus Brocadia”和“Bundatus Kuenenia”相关的厌氧氨氧化细菌和与“Bundatus Methylomirabilis oxyfera”相关的n-damo细菌。据估计，每年总损失50.7克N m−2可能与厌氧氨氧化过程有关，这是在湿地土壤中报告的好氧氨氧化和反硝化的氮通量范围的中间水平。此外，据估计，每年通过n-damo过程氧化的CH 4 m−2总量为0.14 g，而这一速率处于湿地土壤中报告的好氧甲烷氧化速率的低端。
ABSTRACT Anaerobic ammonium oxidation (anammox) and nitrite-dependent anaerobic methane oxidation (n-damo) are two of the most recent discoveries in the microbial nitrogen cycle. In the present study, we provide direct evidence for the cooccurrence of the anammox and n-damo processes in a flooded paddy field in southeastern China. Stable isotope experiments showed that the potential anammox rates ranged from 5.6 to 22.7 nmol N2 g−1 (dry weight) day−1 and the potential n-damo rates varied from 0.2 to 2.1 nmol CO2 g−1 (dry weight) day−1 in different layers of soil cores. Quantitative PCR showed that the abundance of anammox bacteria ranged from 1.0 × 105 to 2.0 × 106 copies g−1 (dry weight) in different layers of soil cores and the abundance of n-damo bacteria varied from 3.8 × 105 to 6.1 × 106 copies g−1 (dry weight). Phylogenetic analyses of the recovered 16S rRNA gene sequences showed that anammox bacteria affiliated with “Candidatus Brocadia” and “Candidatus Kuenenia” and n-damo bacteria related to “Candidatus Methylomirabilis oxyfera” were present in the soil cores. It is estimated that a total loss of 50.7 g N m−2 per year could be linked to the anammox process, which is at intermediate levels for the nitrogen flux ranges of aerobic ammonium oxidation and denitrification reported in wetland soils. In addition, it is estimated that a total of 0.14 g CH4 m−2 per year could be oxidized via the n-damo process, while this rate is at the lower end of the aerobic methane oxidation rates reported in wetland soils.