TY - JOUR
T1 - Depth-specific distribution and significance of nitrite-dependent anaerobic methane oxidation process in tidal flow constructed wetlands used for treating river water
AU - Zhang, Manping
AU - Huang, Jung Chen
AU - Sun, Shanshan
AU - Rehman, Muhammad Muneeb Ur
AU - He, Shengbing
N1 - Funding Information:
This study was financially supported by National Key Research and Development Program of China (No. 2017YFC0506003 ).
Publisher Copyright:
© 2020
PY - 2020/5/10
Y1 - 2020/5/10
N2 - Tidal flow constructed wetlands (TF CWs) have been considered an effective approach to treat contaminated river water, as well as a significant role in global matter cycles, especially for carbon and nitrogen. Notably, it has been thought that methane oxidation was completely catalyzed by the aerobic process, ignoring the anaerobic methane oxidation, such as the nitrite-dependent anaerobic methane oxidation (n-damo) process. In our current work, therefore, we used molecular and stable isotopes to investigate the biodiversity, quantity and potential rate of n-damo bacteria in the TF CWs located in the Xisha Wetland Park in the Yangtze River estuary, China. The results revealed that n-damo process was active in the collected soil cores, with a decreasing trend along water depths and rates ranging from 8.48 to 23.45 nmol CO2 g− 1 dry soil d− 1. The n-damo bacterial contributions to CH4 oxidation and N2 production in TF CWs reached 9.49–26.26% and 20.73–47.11%, respectively, suggesting that n-damo bacteria was an important nitrogen and methane sink in the TF CWs, but had been previously overlooked. The copy numbers of total bacterial 16S rRNA and pmoA genes were 1.84–11.21 × 109 and 0.59–2.72 × 106 copies g− 1 ds, respectively, as the higher abundance was found in the soil at lower water levels during tidal submergence. Diverse n-damo bacterial 16S rRNA gene sequences belonged to group B, C and D were measured, and it was found that group B and C were the most frequently measured n-damo clusters in the TF CWs. In addition, nitrite was the key factor regulating the n-damo bacterial distribution in the TF CWs. This study would broaden our horizons and help us better understand the nitrogen and methane cycles in tidal ecosystems.
AB - Tidal flow constructed wetlands (TF CWs) have been considered an effective approach to treat contaminated river water, as well as a significant role in global matter cycles, especially for carbon and nitrogen. Notably, it has been thought that methane oxidation was completely catalyzed by the aerobic process, ignoring the anaerobic methane oxidation, such as the nitrite-dependent anaerobic methane oxidation (n-damo) process. In our current work, therefore, we used molecular and stable isotopes to investigate the biodiversity, quantity and potential rate of n-damo bacteria in the TF CWs located in the Xisha Wetland Park in the Yangtze River estuary, China. The results revealed that n-damo process was active in the collected soil cores, with a decreasing trend along water depths and rates ranging from 8.48 to 23.45 nmol CO2 g− 1 dry soil d− 1. The n-damo bacterial contributions to CH4 oxidation and N2 production in TF CWs reached 9.49–26.26% and 20.73–47.11%, respectively, suggesting that n-damo bacteria was an important nitrogen and methane sink in the TF CWs, but had been previously overlooked. The copy numbers of total bacterial 16S rRNA and pmoA genes were 1.84–11.21 × 109 and 0.59–2.72 × 106 copies g− 1 ds, respectively, as the higher abundance was found in the soil at lower water levels during tidal submergence. Diverse n-damo bacterial 16S rRNA gene sequences belonged to group B, C and D were measured, and it was found that group B and C were the most frequently measured n-damo clusters in the TF CWs. In addition, nitrite was the key factor regulating the n-damo bacterial distribution in the TF CWs. This study would broaden our horizons and help us better understand the nitrogen and methane cycles in tidal ecosystems.
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U2 - 10.1016/j.scitotenv.2020.137054
DO - 10.1016/j.scitotenv.2020.137054
M3 - Article
C2 - 32036140
AN - SCOPUS:85078821440
SN - 0048-9697
VL - 716
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 137054
ER -