Evaluating the inhibitory effects of Nitrobenzene short-term stress on denitrification performance: Electron behaviors, bacterial and fungal community

Kun Wu; Xinyue Lu; Liuzhou Chen; Jiangzhou Qin; Chenxi Li; Quanlin Zhao; Zhengfang Ye

doi:10.1016/j.chemosphere.2023.140014

Evaluating the inhibitory effects of Nitrobenzene short-term stress on denitrification performance: Electron behaviors, bacterial and fungal community

Chemosphere. 2023 Dec:343:140014. doi: 10.1016/j.chemosphere.2023.140014. Epub 2023 Sep 5.

Authors

Kun Wu¹, Xinyue Lu², Liuzhou Chen², Jiangzhou Qin², Chenxi Li², Quanlin Zhao², Zhengfang Ye³

Affiliations

¹ Department of Environmental Engineering, Peking University, Beijing, 100871, China. Electronic address: kwu5200@163.com.
² Department of Environmental Engineering, Peking University, Beijing, 100871, China.
³ Department of Environmental Engineering, Peking University, Beijing, 100871, China. Electronic address: zhengfangye@163.com.

PMID: 37678599
DOI: 10.1016/j.chemosphere.2023.140014

Abstract

Denitrifying system is a feasible way to remove nitro-aromatic compounds (NACs) in wastewater. However, the toxicity and mechanisms of NACs to denitrification remain unknown. This study investigated effects of nitrobenzene (NB, a typical NAC) on denitrification in short term. Results showed that NB in 10-50 mg/L groups decreased NO₃^--N removal efficiency by 9%-24%, but increased nitrous oxide (N₂O) generation by 6-17fold. Mechanistic research indicated that NB could deteriorate electron behaviors and disturbed enzyme activities of microbial metabolism and denitrification, leading to a decline in denitrification performance. Structural equation modeling revealed that N₂O reductase activity was the core factor in predicting denitrification performance at exposure of NB, with the indirect effects of NADH and electron transport system activity. High-throughput sequencing analysis demonstrated that NB had made an alteration on both bacterial and fungal community structure, as well as their interactions.

Keywords: Bacterial community; Denitrification; Electron behaviors; Fungal community; Nitrobenzene.