Sediment nitrite-dependent methane-oxidizing microorganisms temporally and spatially shift in the Dongjiang River

Abstract

Nitrite-dependent anaerobic methane oxidation (n-damo) process can play an important role in the methane mitigation in the environment. However, the distribution of n-damo organisms in freshwater sediment ecosystem and the associated environmental factors remain essentially unclear. The present study investigated the temporal and spatial dynamics of sediment n-damo community in the freshwater Dongjiang River using quantitative PCR assay and clone library analysis targeting n-damo pmoA gene. Sediment samples were collected at nine locations along the Dongjiang River in May and August in 2015. The remarkable temporal and spatial changes of sediment n-damo community abundance, richness, diversity, and structure occurred in the Dongjiang River and its tributaries. The n-damo pmoA gene in sediments of the Dongjiang River and its tributaries varied from 9.07 × 10 to 3.02 × 10 copies per gram dry sediment. Compared to the stem of the Dongjiang River, tributaries had relatively higher sediment n-damo community size. Sediment n-damo community abundance was higher in August than in May, while an opposite trend was observed for n-damo community richness and diversity. Sediment n-damo community structure showed a great difference between in May and August. Sediment nitrite nitrogen content was positively correlated to n-damo community abundance, but negatively to richness and diversity. Ammonia nitrogen content showed a positive correlation to n-damo community abundance, while n-damo community diversity was negatively correlated to the ratio of total organic carbon to total nitrogen (C/N). In addition, nitrite nitrogen as well as C/N might influence n-damo community structure.

Active pathways of anaerobic methane oxidation across contrasting riverbeds

“…The significance of AOM in rivers is largely unexplored. For example, only molecular evidence of M. oxyfera -like bacteria has been reported previously, with no tracer measurements of activity [33–35]. Here, AOM activity was prevalent in the more reduced sandy riverbeds, whereas no activity could be detected in the more oxygenated gravel riverbeds.…”

“…Aerobic methane oxidation reduces methane emissions from rivers [31, 32], but anaerobic oxidation via nitrite, nitrate, sulfate, and ferric iron cannot be excluded. Only molecular evidence for AOM (presence of M. oxyfera -like sequences) has hitherto been reported for rivers [33–35], although nitrite-dependent AOM activity was discovered in an enrichment culture from canal sediments [6]. Overall, the potential of different AOM pathways to reduce methane emissions from rivers, the microorganisms involved, are poorly known.…”

The denitrifying anaerobic methane oxidation process and microorganisms in the environments: A review

“…High-profile reference groups were also formed after 2013 in cluster 0, as highlighted in Figure 3. They include a highly cited review on nitrite-and nitratedependent DAMO by Welte et al (2016), and studies on primer designs for DAMO archaea (Ding et al, 2015), DAMO bacteria and archaea distributions in paddy field (Vaksmaa et al, 2016;Ding et al, 2016), freshwater rivers (Long et al, 2017b;Shen et al, 2019b), reservoirs (Long et al, 2017a), marshes (Shen et al, 2017), and in coastal systems (Zhang et al, 2018). These references will be discussed in more depth in the later sections of the review.…”

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

“…Ammonia nitrogen (NH 4 + -N), nitrite nitrogen (NO 2 − -N), and nitrate nitrogen (NO 3 − -N) were extracted with 2 mol/L KCl solution for 1 h and then measured colorimetrically by a spectrophotometer (Shimadzu, Japan; Long et al, 2017 ; Xu et al, 2017a ). Dissolved organic carbon (DOC) was extracted by ultra-pure water and quantified using a TOC analyzer (Elementar, Germany).…”