Cooccurrence and potential role of nitrite- and nitrate-dependent methanotrophs in freshwater marsh sediments. (15th October 2017)

• Record Type: Journal Article
• Authors: Shen, Li-dong; Wu, Hong-sheng; Liu, Xu; Li, Ji
• Is Part Of: Water research. Volume 123(2017)
• Page Start: 162
• Page End: 172
• Publication Date: 2017-10-15
• Subjects: Nitrite- and nitrate-dependent anaerobic methane oxidation -- M. oxyfera-like bacteria -- M. nitroreducens-like archaea -- Methane cycling -- Activity -- Freshwater marshes; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2017.06.075
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: Nitrite- and nitrate-dependent anaerobic methane oxidation are mediated by the NC10 bacteria closely related to " Candidatus Methylomirabilis oxyfera" ( M. oxyfera ) and the ANME-2d archaea closely related to " Candidatus Methanoperedens nitroreducens" ( M. nitroreducens ), respectively. Here, we investigated the occurrence and activity of both M. oxyfera -like bacteria and M. nitroreducens -like archaea in the sediment of freshwater marshes in Eastern China. The presence of diverse M. oxyfera -like bacteria (>87% identity to M. oxyfera ) and M. nitroreducens -like archaea (>96% identity to M. nitroreducens ) was confirmed by using Illumina-based total bacterial and archaeal 16S rRNA gene sequencing, respectively. The recovered M. oxyfera -like bacterial sequences accounted for 1.6–4.3% of the total bacterial 16S rRNA pool, and M. nitroreducens -like archaeal sequences accounted for 0.2–1.8% of the total archaeal 16S rRNA pool. The detected numbers of OTUs of the 16S rRNA genes of M. oxyfera -like bacteria and M. nitroreducens -like archaea were 78 and 72, respectively, based on 3% sequence difference. Quantitative PCR showed that the 16S rRNA gene abundance of M. oxyfera -like bacteria (6.1 × 10 6 –3.2 × 10 7 copies g −1 sediment) was 2–4 orders of magnitude higher than that of M. nitroreducens -like archaea (1.4 × 10 3 –3.2 × 10 4 copies g −1 sediment). Stable isotope experiments showed that the addition of both nitrite and nitrate stimulated the anaerobic methane oxidation, while the stimulation by nitrite is more significant than nitrate. Our results provide the first evidence that the M. oxyfera -like bacteria play a more important role than the M. nitroreducens -like archaea in methane cycling in wetland systems. Graphical abstract: Image 1 Highlights: Diverse nitrite- and nitrate-dependent methanotrophs co-occurred in marsh sediments. The stimulation of AOM by nitrite was more significant than nitrate. M. oxyfera -like bacteria could be more important than M. nitroreducens -like archaea.