Biogeographical distribution of denitrifying anaerobic methane oxidizing bacteria in C hinese wetland ecosystems

Summary The discovery of denitrifying anaerobic methane oxidation with nitrite as electron acceptor mediated by ‘ C andidatus   M ethylomirabilis oxyfera’ connected the biogeochemical carbon and nitrogen cycle in a new way. However, it is important to have a comprehensive understanding about the distribution of M . oxyfera ‐like bacteria in the terrestrial realm, especially the wetland ecosystems that are known as the largest natural source of atmospheric methane. Here, our molecular evidence demonstrated that a wide geographical distribution of M . oxyfera ‐like bacteria at oxic/anoxic interfaces of various wetlands ( n  = 91) over the C hinese territory. Intriguingly, the M . oxyfera ‐like bacteria were detected in some extreme environments, indicating that M . oxyfera ‐like bacteria occupied a wide range of habitats. Quantitative polymerase chain reaction estimated that the abundance of M . oxyfera ‐like bacteria ranged from 2.2 × 10 3 to 2.3 × 10 7 copies g −1 dry soil, and up to around 0.62% of the total number of bacteria. Moreover, the M . oxyfera ‐like bacteria showed high biodiversity in wetland ecosystems based on the analysis of 462 pmo A and 287 16S rRNA gene sequences. The current study revealed the widespread distribution and biogeography of M . oxyfera ‐like bacteria in the terrestrial system.