Keystone taxa drive the synchronous production of methane and refractory dissolved organic matter in inland waters

Xinjie Shi; Wanzhu Li; Baoli Wang; Na Liu; Xia Liang; Meiling Yang; Cong-Qiang Liu

doi:10.1016/j.watres.2024.122821

Keystone taxa drive the synchronous production of methane and refractory dissolved organic matter in inland waters

Water Res. 2024 Nov 19:269:122821. doi: 10.1016/j.watres.2024.122821. Online ahead of print.

Authors

Xinjie Shi¹, Wanzhu Li², Baoli Wang³, Na Liu¹, Xia Liang⁴, Meiling Yang¹, Cong-Qiang Liu⁵

Affiliations

¹ Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China.
² Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China. Electronic address: liwanzhu@tju.edu.cn.
³ Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China; Tianjin Bohai Rim Coastal Earth Critical Zone National Observation and Research Station, Tianjin 300072, China. Electronic address: baoli.wang@tju.edu.cn.
⁴ State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China.
⁵ Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China; Tianjin Bohai Rim Coastal Earth Critical Zone National Observation and Research Station, Tianjin 300072, China.

PMID: 39579556
DOI: 10.1016/j.watres.2024.122821

Abstract

The production of both methane (CH₄) and refractory dissolved organic matter (RDOM) depends on microbial consortia in inland waters, and it is unclear yet the link of these two processes and the underlying microbial regulation mechanisms. Therefore, a large-scale survey was conducted in China's inland waters, with the measurement of CH₄ concentrations, DOM chemical composition, microbial community composition, and relative environmental parameters mainly by chromatographic, optical, mass spectrometric, and high-throughput sequencing analyses, to clarify the abovementioned questions. Here, we found a synchronous production of CH₄ and RDOM linked by microbial consortia in inland waters. The increasing microbial cooperation driven by the keystone taxa (mainly Fluviicola and Polynucleobacter) could promote the transformation of labile DOM into RDOM and meanwhile benefit methanogenic microbial communities to produce CH₄. As such, CH₄ and RDOM showed consistent spatial differences, which were mainly influenced by total nitrogen and dissolved oxygen concentrations. This finding deepened the understanding of microbial-driven carbon transformation and will help to more accurately evaluate the carbon source-sink relationship in inland waters.

Keywords: Inland waters; Keystone taxa; Methane; Microbial interactions; Refractory dissolved organic matter.