Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Jiangsu Key Laboratory of Agricultural Meteorology, Department of Ecology, School of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China.
School of Biological & Chemical Sciences, Queen Mary University of London, E1 4NS, London, UK.
Environ Microbiol. 2019 Apr;21(4):1185-1195. doi: 10.1111/1462-2920.14554. Epub 2019 Feb 18.
Anaerobic ammonium oxidation (anammox) and nitrite-dependent anaerobic methane oxidation (n-damo) play important roles in nitrogen and carbon cycling in fresh waters but we do not know how these two processes compete for their common electron acceptor, nitrite. Here, we investigated the spatial distribution of anammox and n-damo across a range of permeable riverbed sediments. Anammox activity and gene abundance were detected in both gravel and sandy riverbeds and showed a simple, common vertical distribution pattern, while the patterns in n-damo were more complex and n-damo activity was confined to the more reduced, sandy riverbeds. Anammox was most active in surficial sediment (0-2 cm), coincident with a peak in hzsA gene abundance and nitrite. In contrast, n-damo activity peaked deeper down (4-8 cm) in the sandy riverbeds, coincident with a peak in n-damo 16S rRNA gene abundance and higher methane concentration. Pore water nitrite, methane and oxygen were key factors influencing the distribution of these two processes in permeable riverbeds. Furthermore, both anammox- and n-damo- activity were positively correlated with denitrification activity, suggesting a role for denitrification in supplying both processes with nitrite. Our data reveal spatial separation between anammox and n-damo in permeable riverbed sediments that potentially avoids them competing for nitrite.
厌氧氨氧化 (anammox) 和亚硝酸盐依赖型厌氧甲烷氧化 (n-damo) 在淡水中的氮碳循环中发挥着重要作用，但我们不知道这两个过程如何争夺它们共同的电子受体亚硝酸盐。在这里，我们研究了一系列可渗透河床沉积物中 anammox 和 n-damo 的空间分布。在砾石和砂质河床中均检测到 anammox 活性和基因丰度，并且表现出简单、共同的垂直分布模式，而 n-damo 的模式则更为复杂，并且 n-damo 活性仅限于更还原的砂质河床。anammox 在表层沉积物（0-2 cm）中最为活跃，与 hzsA 基因丰度和亚硝酸盐峰值相一致。相比之下，n-damo 活性在砂质河床中更深的地方（4-8 cm）达到峰值，与 n-damo 16S rRNA 基因丰度和更高的甲烷浓度峰值相一致。孔隙水亚硝酸盐、甲烷和氧气是影响这些两个过程在可渗透河床中分布的关键因素。此外，anammox 和 n-damo 的活性均与反硝化活性呈正相关，这表明反硝化作用可能为这两个过程提供亚硝酸盐。我们的数据揭示了可渗透河床沉积物中 anammox 和 n-damo 之间的空间分离，这可能避免了它们对亚硝酸盐的竞争。
