Arsenic biotransformation potential of microbial arsH responses in the biogeochemical cycling of arsenic-contaminated groundwater
| Autor: | Jin-Soo Chang, In-Ho Yoon, Kyoung-Woong Kim |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Environmental Engineering Arsenites Health Toxicology and Mutagenesis chemistry.chemical_element 010501 environmental sciences 01 natural sciences Arsenicals Arsenic 03 medical and health sciences chemistry.chemical_compound Biotransformation Arsenic Trioxide Operon Environmental Chemistry Groundwater 0105 earth and related environmental sciences Arsenite Oxidase test biology Pseudomonas putida Public Health Environmental and Occupational Health Arsenate Oxides General Medicine General Chemistry biology.organism_classification Pollution Citrobacter freundii 030104 developmental biology Biodegradation Environmental chemistry Biochemistry Vietnam Arsenates Oxidoreductases Ars operon Oxidation-Reduction Water Pollutants Chemical |
| Zdroj: | Chemosphere. 191 |
| ISSN: | 1879-1298 |
| Popis: | ArsH encodes an oxidoreductase, an NAD(P)H-dependent mononucleotide reductase, with an unknown function, frequently within an ars operon, and is widely distributed in bacteria. Novel arsenite-oxidizing bacteria have been isolated from arsenic-contaminated groundwater and surface soil in Vietnam. We found that ArsH gene activity, with arsenite oxidase in the periplasm; it revealed arsenic oxidation potential of the arsH system. Batch experiment results revealed Citrobacter freundii strain VTan4 (DQ481466) and Pseudomonas putida strain VTw33 (DQ481482) completely oxidized 1 mM of arsenite to arsenate within 30–50 h. High concentrations of arsenic were detected in groundwater and surrounding soil obtained from Vinh Tru village in Ha Nam province (groundwater: 11.0 μg/L to 37.0 μg/L; and soil: 2.5 mg/kg, 390.1 mg/kg), respectively. An arsH gene encoding an organoarsenical oxidase protein was observed in arsenite-oxidizing Citrobacter freundii strain VTan4 (DQ481466), whereas arsB, arsH, and arsH were detected in Pseudomonas putida strain VTw33 (DQ481482). arsH gene in bacteria was first reported from Vietnam for resistance and arsenite oxidase. We proposed that residues, Ser 43, Arg 45, Ser 48, and Tyr 49 are required for arsenic binding and activation of arsH. The ars-mediated biotransformation strongly influenced potential arsenite oxidase enzyme of the operon encoding a homogeneous arsH. Results suggest that the further study of arsenite-oxidizing bacteria may lead to a better understanding of arsenite oxidase responses, such as those of arsH, that may be applied to control biochemical properties; for example, speciation, detoxification, bioremediation, biotransformation, and mobilization of arsenic in contaminated groundwater. |
| Databáze: | OpenAIRE |
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