Denitrifying anaerobic methane oxidation activity and microbial mechanisms in Riparian zone soils of the Yulin River, a tributary of the Three Gorges Reservoir.

Autor: Hu S; Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), College of Environment and Ecology, Chongqing University, Chongqing 400045, China., He Q; Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), College of Environment and Ecology, Chongqing University, Chongqing 400045, China., Liu Y; Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), College of Environment and Ecology, Chongqing University, Chongqing 400045, China., Cheng C; Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), College of Environment and Ecology, Chongqing University, Chongqing 400045, China. Electronic address: ccheng@cqu.edu.cn.
Jazyk: angličtina
Zdroj: Water research [Water Res] 2024 Nov 28; Vol. 271, pp. 122865. Date of Electronic Publication: 2024 Nov 28.
DOI: 10.1016/j.watres.2024.122865
Abstrakt: Riparian zones are recognized as major sources of greenhouse gas emissions, particularly methane (CH 4 ). Denitrifying anaerobic methane oxidation (DAMO) has garnered growing attention due to its significant contribution to mitigating CH 4 emissions in wetland environments. Nonetheless, the specific role and microbial mechanisms of DAMO in controlling CH 4 release within riparian zones are still not well comprehended. This study employed isotopic labeling experiments to measure the nitrate-dependent anaerobic methane oxidation (NaDAMO) and nitrite-dependent anaerobic methane oxidation (NiDAMO) potential of soil samples from riparian zones that were collected during different hydrological cycles. Moreover, soil physicochemical properties, DAMO activity, and microbial abundance were integrated to analyze the key factors and mechanisms influencing DAMO in riparian zone soils. The isotope tracer results showed that NaDAMO activities (1.41-11.93 nmol 13 CO 2 g -1 day -1 ) were significantly higher than NiDAMO activities (0.66-9.19 nmol 13 CO 2 g -1 day -1 ) in the riparian zone (p < 0.05). NiDAMO activities were more strongly influenced by hydrological variations compared to NaDAMO activities, exhibiting higher levels during the discharge period (2.78-9.19 nmol 13 CO 2 g -1 day -1 ) compared to the impoundment period (0.66-4.10 nmol 13 CO 2 g -1 day -1 ). The qPCR analysis showed that the gene copies of NaDAMO archaeal mcrA (10 7 copies g -1 ) were approximately ten times greater than those of NiDAMO bacterial pmoA (10 6 copies g -1 ) in the majority of the sampling sites. Correlation analyses revealed that NiDAMO activity was influenced by soil pH (p < 0.05), while NaDAMO microbes were influenced by temperature, organic carbon, and ammonia nitrogen concentrations (p < 0.05). In summary, this research explored how hydrological changes in the riparian zone influence DAMO activities and their underlying mechanisms, providing a theoretical basis for mitigating CH 4 emissions in riparian zones of reservoir regions.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024. Published by Elsevier Ltd.)
Databáze: MEDLINE
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