1. Photo-produced aromatic compounds stimulate microbial degradation of dissolved organic carbon in thermokarst lakes.
- Author
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Hu, Jie, Kang, Luyao, Li, Ziliang, Feng, Xuehui, Liang, Caifan, Wu, Zan, Zhou, Wei, Liu, Xuning, Yang, Yuanhe, and Chen, Leiyi
- Subjects
DISSOLVED organic matter ,ION cyclotron resonance spectrometry ,THERMOKARST ,AROMATIC compounds ,PHOTODEGRADATION - Abstract
Photochemical and biological degradation of dissolved organic carbon (DOC) and their interactions jointly contribute to the carbon dioxide released from surface waters in permafrost regions. However, the mechanisms that govern the coupled photochemical and biological degradation of DOC are still poorly understood in thermokarst lakes. Here, by combining Fourier transform ion cyclotron resonance mass spectrometry and microbial high-throughput sequencing, we conducted a sunlight and microbial degradation experiment using water samples collected from 10 thermokarst lakes along a 1100-km permafrost transect. We demonstrate that the enhancement of sunlight on DOC biodegradation is not associated with the low molecular weight aliphatics produced by sunlight, but driven by the photo-produced aromatics. This aromatic compound-driven acceleration of biodegradation may be attributed to the potential high abilities of the microbes to decompose complex compounds in thermokarst lakes. These findings highlight the importance of aromatics in regulating the sunlight effects on DOC biodegradation in permafrost-affected lakes. The mechanism of photochemical and biological degradation of DOC is unclear, especially in thermokarst lakes. Here, the authors find that photo-produced aromatic compounds rather than aliphatic compounds stimulate the microbial degradation of DOC. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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