Recently, a new oxygenic pathway has been proposed based on the disproportionation of NO with putative NO dismutase (Nod). In addition to a new process in nitrogen cycling, this process provides ecological advantages for the degradation of substrates in anaerobic conditions, which is of great significance for wastewater treatment. However, the Nod distribution in aquatic environments is rarely investigated. In this study, we obtained the nod genes with an abundance of 2.38 ± 0.96 × 10⁵ copies per gram of dry soil from the Zoige wetland and aligned the molecular characteristics in the corresponding Nod sequences. These Nod sequences were not only found existing in NC10 bacteria, but were also found forming some other clusters with Nod sequences from a WWTP reactor or contaminated aquifers. Moreover, a new subcluster in the aquifer-similar cluster was even dominant in the Zoige wetland and was named the Z-aquifer subcluster. Additionally, soils from the Zoige wetland showed a high potential rate (10.97 ± 1.42 nmol of CO₂ per gram of dry soil per day) for nitrite-dependent anaerobic methane oxidation (N-DAMO) with low abundance of NC10 bacteria, which may suggest a potential activity of Nod in other clusters when considering the dominance of the Z-aquifer subcluster Nod. In conclusion, we verified the occurrence of Nod in an alpine wetland for the first time and found a new subcluster to be dominant in the Zoige wetland. Moreover, this new subcluster of Nod may even be active in the N-DAMO process in this alpine wetland, which needs further study to confirm.

中文翻译：

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在具有新的显性亚群的高山湿地中发生假定的一氧化氮歧化酶（Nod）和潜在的甲烷汇能力。

近来，基于NO与假定的NO歧化酶（Nod）的歧化，已经提出了新的氧途径。除了氮循环的新工艺外，该工艺还为厌氧条件下底物的降解提供了生态优势，这对废水处理具有重要意义。但是，很少研究水生环境中的Nod分布。在这项研究中，我们获得了2.38±0.96×10 ⁵丰度的nod基因从Zoige湿地每克干燥土壤中复制1份，并在相应的Nod序列中排列分子特征。这些Nod序列不仅发现存在于NC10细菌中，还发现它们与其他WWTP反应器或受污染的含水层中的Nod序列形成簇。此外，在Zoige湿地中，与含水层相似的集群中的一个新的子集群甚至占主导地位，被称为Z-含水层子集群。此外，若尔盖（Zoige）湿地的土壤显示出很高的潜在潜力（CO ₂为10.97±1.42 nmol每克每天的干燥土壤中）的NC10细菌含量较低的亚硝酸盐依赖性厌氧甲烷氧化（N-DAMO），考虑到Z含水层亚簇Nod的优势，这可能表明Nod在其他簇中具有潜在的活性。总之，我们首次验证了在高山湿地中Nod的发生，并发现了一个新的亚群在Zoige湿地中占主导地位。此外，这种新的Nod亚群甚至可能在该高山湿地的N-DAMO过程中起作用，有待进一步研究确认。