Terrestrial dissolved organic matter inputs affect the nitrous oxide emission revealed by FT-ICR MS

Zezheng Wang; Lu Li; Chengchao Liao; Min Deng; Xiaoyan Jiang; Yongxia Huang; Zhiwei Xia; Kang Song

doi:10.1016/j.scitotenv.2024.177765

Terrestrial dissolved organic matter inputs affect the nitrous oxide emission revealed by FT-ICR MS

Sci Total Environ. 2024 Nov 28:957:177765. doi: 10.1016/j.scitotenv.2024.177765. Online ahead of print.

Authors

Zezheng Wang¹, Lu Li¹, Chengchao Liao¹, Min Deng¹, Xiaoyan Jiang², Yongxia Huang¹, Zhiwei Xia³, Kang Song⁴

Affiliations

¹ State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² School of Materials Science and Chemical Engineering, Anhui Jianzhu University, Hefei 230601, China.
³ State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China.
⁴ State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: sk@ihb.ac.cn.

PMID: 39612710
DOI: 10.1016/j.scitotenv.2024.177765

Abstract

Nitrous oxide (N₂O) emission from lake systems could be affected via intrusion of terrestrial organic matter, causing impairment in biogeochemical cycling. The sources and mechanisms by which DOM (Dissolved organic matter) alters emissions of N₂O are poorly understood. Here, we simulate different terrestrial DOM (anthropogenic sources, natural sources, and surface runoff) to assess the mechanisms affecting N₂O emissions with variations of DOM. We used a combination of absorption spectroscopy, excitation-emission matrix fluorescence, and Fourier transform ion cyclotron resonance mass spectrometry to characterize DOM comprehensively. For the characterization of DOM, a combination of absorption spectroscopy, excitation-emission matrix fluorescence, and Fourier transform ion cyclotron resonance mass spectrometry was used. Microbial analysis was conducted to identify the potential microbial mechanisms. Different terrestrial DOM inputs primarily impact N₂O emissions through the denitrification process (14.52 %, p < 0.05), with significant effects on the abundance of narG (12.97 %, p < 0.05) and nir_K+S (10.13 %, p < 0.05). The biodegradable components in sediments directly promote N₂O emissions, while in aquatic systems, the labile components (proteins, sugars, and lipids-like) were preferentially metabolized, producing reluctant derivatives. The biodegradable components (i.e., protein-like) from anthropogenic sources rapidly facilitate N₂O production. Natural and surface runoff sources were the significant drivers for the continuous release and metabolism of DOM. N₂O Loss emissions are negatively influenced by the regulation of carbon and nitrogen metabolism by nitrifiers and denitrifies in the sediment (p < 0.001). Metabolism of carbon and nitrogen regulated by nitrifier and denitrifies in the sediments negatively influences N₂O flux (p < 0.001). N₂O emissions were mainly influenced by bioavailability of inputs: DOM and varying terrestrial conditions. The results provide a theoretical base for the management of greenhouse gas emissions from lakes.

Keywords: Dissolved organic matter; FT-ICR-MS; Microbial mechanism; Nitrous oxide emission; Terrestrial input.