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Simultaneous degradation of triazophos, methamidophos and carbofuran pesticides in wastewater using an Enterobacter bacterial bioreactor and analysis of toxicity and biosafety.
- Source :
-
Chemosphere [Chemosphere] 2020 Dec; Vol. 261, pp. 128054. Date of Electronic Publication: 2020 Aug 21. - Publication Year :
- 2020
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Abstract
- Triazophos (TAP), methamidophos (MAP) and carbofuran (CF) pesticides are highly toxic, soluble and absorbable. Efficient co-degradation of multi-pesticides is rare reported. The objectives of this study were to investigate TAP, MAP and CF co-degradative ability of Enterobacter sp. Z1 and study the degradation mechanisms. Strain Z1 was shown to efficiently co-degrade TAP, MAP and CF when they were used as primary carbon sources. The degradation occurred over a wide range of temperatures, pH values and pesticide concentrations and followed first-order kinetics. Under the optimum conditions (37 °C, pH 7 and 100 mg/L of each pesticide), the degradation efficiencies were 100%, 100%, and 95.3% for TAP, MAP and CF, respectively. In addition, strain Z1 could simultaneously degrade TAP, MAP, CF and total nitrogen in wastewater in a batch bioreactor, with high removal efficiencies of 98.3%, 100%, 98.7% and 100%, respectively. Genomics, proteomics, qRT-PCR and gene overexpression analyses revealed that the degradation mechanisms involved the activities of multiple proteins, among which, organophosphorus hydrolase (Oph) and 3-hydroxyacyl-CoA dehydrogenase (PaaC) are primarily responsible for TAP and MAP degradation, while carbofuran hydrolase (Mcd) and amidohydrolase (RamA) primarily degrade CF. Among these enzymes, PaaC and RamA are newly identified pesticide-degrading enzymes. Toxicity assays of strain Z1 using reporter recombinase gene (recA) and zebrafish showed that there was no accumulation of toxic metabolites during the degradation process. Biosafety test using zebrafish showed that the strain was nontoxic toward zebrafish. Strain Z1 provides a good purification effect for pesticides-containing wastewater and novel microbial pesticide-degrading mechanisms were discovered.<br />Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.<br /> (Copyright © 2020 Elsevier Ltd. All rights reserved.)
- Subjects :
- Biodegradation, Environmental
Carbofuran analysis
Carbofuran toxicity
Containment of Biohazards
Enterobacter drug effects
Hydrolases metabolism
Organothiophosphates analysis
Organothiophosphates toxicity
Organothiophosphorus Compounds analysis
Organothiophosphorus Compounds toxicity
Triazoles analysis
Triazoles toxicity
Bioreactors microbiology
Enterobacter metabolism
Pesticides analysis
Pesticides toxicity
Wastewater chemistry
Water Pollutants, Chemical analysis
Water Pollutants, Chemical toxicity
Water Purification methods
Subjects
Details
- Language :
- English
- ISSN :
- 1879-1298
- Volume :
- 261
- Database :
- MEDLINE
- Journal :
- Chemosphere
- Publication Type :
- Academic Journal
- Accession number :
- 33113645
- Full Text :
- https://doi.org/10.1016/j.chemosphere.2020.128054