Simultaneous methane mitigation and nitrogen removal by denitrifying anaerobic methane oxidation in lake sediments

Yanan Bai; Wangting Yang; Hanyu Li; Qinan Hu; Sile Wen; Lidong Shen; Yuzhi Song

doi:10.1016/j.scitotenv.2024.173134

Simultaneous methane mitigation and nitrogen removal by denitrifying anaerobic methane oxidation in lake sediments

Sci Total Environ. 2024 Jul 1:932:173134. doi: 10.1016/j.scitotenv.2024.173134. Epub 2024 May 9.

Authors

Yanan Bai¹, Wangting Yang², Hanyu Li², Qinan Hu², Sile Wen², Lidong Shen³, Yuzhi Song⁴

Affiliations

¹ School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing 210044, China; Key Laboratory of Ecosystem Carbon Source and Sink, China Meteorological Administration (ECSS-CMA), School of Ecology and Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China.
² Key Laboratory of Ecosystem Carbon Source and Sink, China Meteorological Administration (ECSS-CMA), School of Ecology and Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China.
³ School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing 210044, China; Key Laboratory of Ecosystem Carbon Source and Sink, China Meteorological Administration (ECSS-CMA), School of Ecology and Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China. Electronic address: shenld@nuist.edu.cn.
⁴ Key Laboratory of Ecosystem Carbon Source and Sink, China Meteorological Administration (ECSS-CMA), School of Ecology and Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China. Electronic address: syz70@nuist.edu.cn.

PMID: 38734096
DOI: 10.1016/j.scitotenv.2024.173134

Abstract

Methane (CH₄) is a potent greenhouse gas, with lake ecosystems significantly contributing to its global emissions. Denitrifying anaerobic methane oxidation (DAMO) process, mediated by NC10 bacteria and ANME-2d archaea, links global carbon and nitrogen cycles. However, their potential roles in mitigating methane emissions and removing nitrogen from lake ecosystems remain unclear. This study explored the spatial variations in activities of nitrite- and nitrate-DAMO and their functional microbes in Changdanghu Lake sediments (Jiangsu Province, China). The results showed that although the average abundance of ANME-2d archaea (5.0 × 10⁶ copies g^-1) was significantly higher than that of NC10 bacteria (2.1 × 10⁶ copies g^-1), the average potential rates of nitrite-DAMO (4.59 nmol ¹³CO₂ g^-1 d^-1) and nitrate-DAMO (5.01 nmol ¹³CO₂ g^-1 d^-1) showed no significant difference across all sampling sites. It is estimated that nitrite- and nitrate-DAMO consumed approximately 6.46 and 7.05 mg CH₄ m^-2 d^-1, respectively, which accordingly achieved 15.07-24.95 mg m^-2 d^-1 nitrogen removal from the studied lake sediments. Statistical analyses found that nitrite- and nitrate-DAMO activities were both significantly related to sediment nitrate contents and ANME-2d archaeal abundance. In addition, NC10 bacterial and ANME-2d archaeal community compositions showed significant correlations with sediment organic carbon content and water depth. Overall, this study underscores the dual roles of nitrite- and nitrate-DAMO processes in CH₄ mitigation and nitrogen elimination and their key environmental impact factors (sediment organic carbon and inorganic nitrogen contents, and water depth) in shallow lake, enhancing the understanding of carbon and nitrogen cycles in freshwater aquatic ecosystems.

Keywords: Abundance; Activity; Community composition; Nitrate-DAMO; Nitrite-DAMO.

MeSH terms

Anaerobiosis
Archaea / metabolism
Bacteria / metabolism
China
Denitrification*
Geologic Sediments* / chemistry
Geologic Sediments* / microbiology
Lakes* / chemistry
Lakes* / microbiology
Methane* / analysis
Methane* / metabolism
Nitrogen* / analysis
Oxidation-Reduction*
Water Pollutants, Chemical / analysis