Structure and distribution of nitrite-dependent anaerobic methane oxidation bacteria vary with water tables in Zoige peatlands

Abstract

The recently discovered nitrite-dependent anaerobic methane oxidation (n-damo) is an important methane sink in natural ecosystems performed by NC10 phylum bacteria. However, the effect of water table (WT) gradient due to global change on n-damo bacterial communities is not well studied in peatlands. Here, we analysed the vertical distribution (0–100 cm) of n-damo bacterial communities at three sites with different WTs of the Zoige peatlands in the Qinghai-Tibetan Plateau. Using an n-damo bacterial specific 16S rRNA gene clone library, we obtained 25 operational taxonomic units (OTUs) that could be divided into Groups A, B, C, D and E (dominated by A and B). The dominant group was Group B at the high (OTU14 and OTU20) and intermediate (OTU7 and OTU8) WT sites and Group A was dominant at the low WT site (OTU6 and OTU5). Using high-throughput sequencing, we observed that n-damo bacteria mainly distributed in subsurface soils (50–60 and 20–30 cm), and their relative abundances were higher at the low WT site than at the other two sites. In addition, we found that pH and nitrate were positively correlated with Group A, while total organic carbon, total nitrogen and ammonia were positively associated with Group B. Our study provides new insights into our understanding of the response of n-damo bacteria to WT gradient in peatlands, with important implications for global change.

How do water table drawdown, duration of drainage, and warming influence greenhouse gas emissions from drained peatlands of the Zoige Plateau?

“…Since Proteobacteria engage in bacteriochlorophyll‐dependent photosynthesis, and they show an important role in the decomposition of SOM in environments where nutrients or water are lacking (Ren et al, 2018). We found that the relative abundance of Deltaproteobacteria increased with watertable drawdown, consistent with other studies (Cao et al, 2018; Siljanen et al, 2012; Zhong et al, 2020). These methanotrophs can effectively oxidize methane (Hanson & Hanson, 1996).…”

Environmental Filtering by pH and Salinity Jointly Drives Prokaryotic Community Assembly in Coastal Wetland Sediments

“…A slightly acidic or neutral microenvironment is conducive to the decomposition of plant litter, which could affect nutrient contents in coastal wetland sediments (Wang Y. et al, 2020). Previous studies indicated that pH was negatively associated with microbial α-diversity (Jiao and Lu, 2020b;Zhong et al, 2020). In this study, a neutral pH (from 6 to 7.5) could lead to a high α-diversity of bacterial and archaeal communities.…”

“…Environmental factors have significant effects on driving microbial community assembly (Rath and Rousk, 2015;Jiao and Lu, 2020a;Yu et al, 2021b). Previous studies indicated that pH could influence the diversity and structure of microbial communities at local (Tripathi et al, 2014;Yu et al, 2020;Zhong et al, 2020), regional (Griffiths et al, 2011;Tripathi et al, 2012;Jiao et al, 2019) and global scales (Fierer and Jackson, 2006). Recent studies found that pH regulated the balance between stochastic and deterministic processes of microbial community assembly in freshwater lakes (Ren et al, 2015) and successional soils (Tripathi et al, 2018).…”

Transcriptional dynamics of methane-cycling microbiomes are linked to seasonal CH4 fluxes in two hydromorphic and organic-rich grassland soils

“…Another study found a similar proportion of anaerobic methanotrophs (5.7-25.8%) in the upper 10 cm of urban wetlands [65]. Zhong et al [66] found that the relative abundance of anaerobic methanotrophs in wetland soils was highest at the 50-60 cm depth. We investigated only to a depth of 30 cm.…”