Spatial variations of activity and community structure of nitrite-dependent anaerobic methanotrophs in river sediment

Denitrifying anaerobic methane-oxidizing bacteria in river networks of the Taihu Basin: Community dynamics and assembly process

“…Our results showed that DAMO bacteria were mainly divided into Group A and Group B with Group B as the dominant subgroups (Figure 1). This observation was consistent with previous studies in other rivers (Shen et al, 2014;Cheng et al, 2022), indicating that Group B might be more adaptable in river ecosystems than Group A. Previous studies have confirmed that Group A had the ability to oxidize methane by enrichment culture and genomic analysis (Ettwig et al, 2009;He et al, 2015;Wang et al, 2016;Xu et al, 2018).…”

“…Previous studies have confirmed the distribution of DAMO bacteria in the river ecosystem ( Shen et al, 2014 ; Cheng et al, 2022 ), while the dynamics of different subgroups of DAMO bacteria remain poorly explored. In this study, amplicon sequencing combined with phylogenetic analysis was applied to track the dynamics of DAMO bacterial communities in the river ecosystem.…”

“…In contrast, stochastic processes believe that random factors, such as birth, death, speciation, limited dispersal, and immigration, shape microbial communities (Chave, 2004;Zhou and Ning, 2017). Previous studies have confirmed the distribution of DAMO bacteria in freshwater ecosystems with focus on its diversity and abundance (Shen et al, 2014;Cheng et al, 2022), while the underlying community assembly process is still unclear. Moreover, microbial communities often exhibit an uneven distribution, with a few abundant taxa coexisting with a large number of rare taxa (Fuhrman, 2009;Jia et al, 2018).…”

“…According to the availability of oxygen, methane oxidation can be divided into two distinct processes: aerobic oxidation of methane and anaerobic oxidation of methane (AOM). In freshwater ecosystem, denitrifying anaerobic methane oxidation (DAMO) is the most widely investigated AOM pathway ( Shen et al, 2014 ; Cheng et al, 2022 ), which can couple methane oxidation with denitrification by using nitrate/nitrite as the electron acceptors ( Strous and Jetten, 2004 ; Raghoebarsing et al, 2006 ). DAMO bacteria, belonging to the NC10 phylum ( Ettwig et al, 2010 ), is one of the major functional microorganisms participating in DAMO process.…”

“…Up to now, five phylogenetically distinct subgroups of DAMO bacteria (Groups A–E) have been verified ( Chen et al, 2016 ), among which Group A and Group B were widely distributed in freshwater ecosystem. For example, Group B was more abundant than Group A in the Qiantang River ( Shen et al, 2014 ), while the dominant subgroups were found to be distinct in different reaches in the Wuxijiang River ( Cheng et al, 2022 ). However, the dynamics of different subgroups of DAMO bacteria and the underlying driving factors remained largely unknown.…”