Evidence for nitrite-dependent anaerobic methane oxidation as a previously overlooked microbial methane sink in wetlands

• DOI: 10.1073/pnas.1318393111
• Publication Date: 2014-03-11T01:34:20Z
• Authors: Bao-lan Hu; Li-dong Shen; Xu Lian; Qun Zhu; Shuai Liu; Qian Huang; Zhan-fei He; Sha Geng; Dong-qing Cheng; Li-ping Lou; Xiang-yang Xu; Ping Zheng; Yun-feng He
• Keywords: Methanotroph; Methane Monooxygenase; Ammonia monooxygenase

The process of nitrite-dependent anaerobic methane oxidation (n-damo) was recently discovered and shown to be mediated by "Candidatus Methylomirabilis oxyfera" (M. oxyfera). Here, evidence for n-damo in three different freshwater wetlands located southeastern China obtained using stable isotope measurements, quantitative PCR assays, 16S rRNA particulate monooxygenase gene clone library analyses. Stable experiments confirmed the occurrence examined wetlands, potential rates ranged from 0.31 5.43 nmol CO2 per gram dry soil day at depths cores. A combined analysis genes demonstrated that M. oxyfera-like bacteria were mainly present deep with a maximum abundance 3.2 × 10(7) copies soil. It is estimated ∼0.51 g CH4 m(-2) year could linked based on measured rates. This study presents previously unidentified confirmation overlooked microbial sink has globally important due increasing nitrogen pollution.