Regulation of potential denitrification rates in sediments by microbial-driven elemental coupled metabolisms

Mingzhu Zhang; Jianjun Zha; Yufei Dong; Qin Zhang; Shouyang Pang; Shengni Tian; Qingye Sun

doi:10.1016/j.jenvman.2023.119320

Regulation of potential denitrification rates in sediments by microbial-driven elemental coupled metabolisms

J Environ Manage. 2023 Dec 15:348:119320. doi: 10.1016/j.jenvman.2023.119320. Epub 2023 Oct 14.

Authors

Mingzhu Zhang¹, Jianjun Zha², Yufei Dong¹, Qin Zhang¹, Shouyang Pang¹, Shengni Tian³, Qingye Sun⁴

Affiliations

¹ School of Life Sciences, Anhui Agricultural University, Hefei, Anhui Province, China.
² Southern University of Science and Technology Taizhou Research Insitute, Zhejiang Province, China.
³ School of Life Sciences, Anhui Agricultural University, Hefei, Anhui Province, China. Electronic address: tiansn@ahau.edu.cn.
⁴ School of Resources and Environmental Engineering, Anhui University, China.

PMID: 37839205
DOI: 10.1016/j.jenvman.2023.119320

Abstract

Microbial driven coupled processes between denitrification and methane/sulfur metabolism play a very substantial role in accelerating nitrogen removal in river sediments. Until now, little is known about how element coupling processes alter nitrogen metabolism by the microbial functional communities. The primary objective of this research was to clarify the contributory role of microbial-mediated coupled processes in controlling denitrification. Specifically, the study sought to identify the key bioindicators (or metabolic pathway) for preferably regulating and predicting potential denitrification rate (PDR). Here, a total of 40 sediment samples were collected from the inflow rivers of Chaohu Lake under nitrogen stress. The results revealed the ecological importance of methanogens and sulfate reducing bacteria in the microbial interaction network. Correlations between quantitative or predicted genes showed that the methanogenic gene (mcrA) was synergistic with denitrifying genes, further unraveling that the key role of methanogenesis in denitrification process for facilitating nitrogen removal. The PDR of sediments ranged from 0.03 to 133.21 μg N·g^-1·h^-1. The study uncovered specific environmental factors (NH₄⁺ and OM) and microbial indicators (nosZ, mcrA, Paracoccus, Thauera, Methanobrevibacter and Desulfomicrobium) as potential contributors to the variations in PDR. Structural Equation Model (SEM) analysis revealed a significant direct effect of NH₄⁺ on PDR, evidenced by a standardized coefficient (λ) of 0.77 (P < 0.001). Additionally, the findings also emphasized the salient role of methanogens (Methanobrevibacter) and methanogenic gene (mcrA) in indicating PDR. The research's aforementioned findings shed light on the substantial consequences of methanogenesis on nitrogen metabolism in coupled processes, enabling improved control of nitrogen pollution in river sediments. This study provided fresh perspectives on the effects of multiple functional taxa on denitrification, and reinforces the significance of coupling processes for nitrogen removal.

Keywords: Bioindicator; Coupled metabolism; Functional community; Functional gene; Potential denitrification rate.

MeSH terms

Denitrification*
Geologic Sediments / chemistry
Lakes
Nitrogen / metabolism
Rivers* / chemistry

Substances

Nitrogen