Transcriptional and molecular simulation analysis of the response mechanism of anammox bacteria to 3,4-dimethylpyrazole phosphate stress

Cui-Zhong Chen; Jin Wang; Yi-Cheng Wang; Hui-Min Fu; Xiao-Wei Xu; Peng Yan; You-Peng Chen

doi:10.1016/j.jhazmat.2024.136867

Transcriptional and molecular simulation analysis of the response mechanism of anammox bacteria to 3,4-dimethylpyrazole phosphate stress

J Hazard Mater. 2024 Dec 12:485:136867. doi: 10.1016/j.jhazmat.2024.136867. Online ahead of print.

Authors

Cui-Zhong Chen¹, Jin Wang², Yi-Cheng Wang³, Hui-Min Fu⁴, Xiao-Wei Xu³, Peng Yan³, You-Peng Chen⁵

Affiliations

¹ Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China; College of Water Conservancy & Architectural Engineering, Shihezi University, Shihezi 832000, China.
² Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
³ Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China.
⁴ Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China; National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing 400067, China.
⁵ Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China. Electronic address: [email protected].

PMID: 39675083
DOI: 10.1016/j.jhazmat.2024.136867

Abstract

Anaerobic ammonium oxidation (anammox) and nitrification are two vital biological pathways for ammonium oxidation, pivotal in microbial nitrogen cycling. 3,4-Dimethylpyrazole phosphate (DMPP) is commonly used as inhibitors in agricultural soils to reduce nitrogen losses from farmland, while whether it affect anammox is an open question. Acute inhibition tests revealed that 53.5 mg·L^-1 DMPP caused 50 % reduction in anammox bacteria. After 36 days of prolonged exposure to 5 mg·L^-1 DMPP, the ammonium(nitrite) removal rate of endnote decreased from 78.39(94.78) to 13.57(15.28) mgN·gVSS^-1·d^-1. Additionally, the abundance of Ca. Kuenenia decreased from 36.5 % to 6.06 %. Transcriptomic analysis revealed that the mRNA levels of ammonium transport genes (amt_1 and amt_4), and hydrazine synthase (hzs) were significantly downregulated. Molecular docking simulations indicated that DMPP bound with ammonium transport and hydrazine synthesis. This interaction hindered the transcriptional levels of genes encoding ammonium transporters and hzs. The study has guiding value to reduce the nitrogen loss involved in anammox bacteria in agricultural soils under the application of DMPP.

Keywords: Ammonium transport; Anammox; DMPP exposure; Hydrazine synthase; Inhibition mechanism.