Perturbation of clopyralid on bio-denitrification and nitrite accumulation: Long-term performance and biological mechanism

Suyun Sun; Ya-Nan Hou; Wei Wei; Hafiz Muhammad Adeel Sharif; Cong Huang; Bing-Jie Ni; Haibo Li; Yuanyuan Song; Caicai Lu; Yi Han; Jianbo Guo

Environmental Science and Ecotechnology (Jan 2022)

Perturbation of clopyralid on bio-denitrification and nitrite accumulation: Long-term performance and biological mechanism

Suyun Sun,
Ya-Nan Hou,
Wei Wei,
Hafiz Muhammad Adeel Sharif,
Cong Huang,
Bing-Jie Ni,
Haibo Li,
Yuanyuan Song,
Caicai Lu,
Yi Han,
Jianbo Guo

Affiliations

Suyun Sun: Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, 300384, China; National Technology Innovation Center of Synthetic Biology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
Ya-Nan Hou: Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, 300384, China; National Technology Innovation Center of Synthetic Biology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China; Corresponding author. Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, 300384, China.
Wei Wei: Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia
Hafiz Muhammad Adeel Sharif: College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, China
Cong Huang: National Technology Innovation Center of Synthetic Biology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
Bing-Jie Ni: Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia
Haibo Li: Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, 300384, China
Yuanyuan Song: Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, 300384, China
Caicai Lu: Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, 300384, China
Yi Han: Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, 300384, China
Jianbo Guo: Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, 300384, China; Corresponding author.

Journal volume & issue: Vol. 9
p. 100144

Abstract

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The contaminant of herbicide clopyralid (3,6-dichloro-2- pyridine-carboxylic acid, CLP) poses a potential threat to the ecological system. However, there is a general lack of research devoted to the perturbation of CLP to the bio-denitrification process, and its biological response mechanism remains unclear. Herein, long-term exposure to CLP was systematically investigated to explore its influences on denitrification performance and dynamic microbial responses. Results showed that low-concentration of CLP (<15 mg/L) caused severe nitrite accumulation initially, while higher concentrations (35–60 mg/L) of CLP had no further effect after long-term acclimation. The mechanistic study demonstrated that CLP reduced nitrite reductase (NIR) activity and inhibited metabolic activity (carbon metabolism and nitrogen metabolism) by causing oxidative stress and membrane damage, resulting in nitrite accumulation. However, after more than 80 days of acclimation, almost no nitrite accumulation was found at 60 mg/L CLP. It was proposed that the secretion of extracellular polymeric substances (EPS) increased from 75.03 mg/g VSS at 15 mg/L CLP to 109.97 mg/g VSS at 60 mg/L CLP, which strengthened the protection of microbial cells and improved NIR activity and metabolic activities. Additionally, the biodiversity and richness of the microbial community experienced a U-shaped process. The relative abundance of denitrification- and carbon metabolism-associated microorganisms decreased initially and then recovered with the enrichment of microorganisms related to the secretion of EPS and N-acyl-homoserine lactones (AHLs). These microorganisms protected microbe from toxic substances and regulated their interactions among inter- and intra-species. This study revealed the biological response mechanism of denitrification after successive exposure to CLP and provided proper guidance for analyzing and treating herbicide-containing wastewater.

Published in Environmental Science and Ecotechnology

ISSN: 2666-4984 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Geography. Anthropology. Recreation: Environmental sciences; Technology: Environmental technology. Sanitary engineering
Website: https://www.journals.elsevier.com/environmental-science-and-ecotechnology

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