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Yu X, Xiong F, Zhou C, Luo Z, Zhou Z, Chen J, Sun K. Uranium bioprecipitation mediated by a phosphate-solubilizing Enterobacter sp. N1-10 and remediation of uranium-contaminated soil. Sci Total Environ 2024; 906:167688. [PMID: 37820798 DOI: 10.1016/j.scitotenv.2023.167688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/27/2023] [Accepted: 10/07/2023] [Indexed: 10/13/2023]
Abstract
Uranium (U) pollution in soils is prevalent worldwide and poses a significant health risk that will require remediation approaches. However, traditional U bioreduction by sulfate reducing bacteria (SRB) are sensitive to oxygen and are not suitable for treating aerobic topsoil. Bioprecipitation of U into uranyl phosphate (UP) mediated by phosphate-solubilizing microorganism (PSM) is not affected by oxygen. In this study, PSM strains were isolated and used for U-contaminated soil remediation. Microbial metabolites and the mechanism of PSM bioprecipitation were revealed. The results showed that strain Enterobacter sp. N1-10 had the highest phosphate-solubilizing capacity (dissolved P was 409.51 ± 8.48 mg/L). Uranium bioprecipitation was investigated by culturing the bacterium in the presence of 50 mg/L U and in the cell-free culture supernatant. The results showed that strain N1-10 had a high U removal rate (99.45 ± 0.43 %) after adding 50 mg/L U to the culture medium. A yellow precipitate was immediately formed when uranyl nitrate solution was added to the cell-free culture supernatant. The analysis indicated that bacterium produced lactic acid (37.58 mg/L), citric acid (4.76 mg/L), succinic acid (2.03 mg/L), and D-glucuronic acid (1.94 mg/L); the four organic acids solubilized Ca3(PO4)2 to form stable uranyl phosphate precipitate. The application of strain N1-10 and Ca3(PO4)2 significantly decreased the bioavailability of soil U (43.54 ± 0.52 %). In addition, pot experiments showed that PSM N1-10 and Ca3(PO4)2 promoted plant growth and markedly reduced U accumulation by pakchoi. These results demonstrate that PSM N1-10 and Ca3(PO4)2 exhibit a great potential for U bioremediation.
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Affiliation(s)
- Xiaoxia Yu
- School of Water Resources and Environmental Engineering, East China University of Technology, NanChang 330013, Jiangxi, China; State Key Laboratory of Nuclear Resources and Environmental, East China University of Technology, NanChang 330013, Jiangxi, China.
| | - Feng Xiong
- School of Water Resources and Environmental Engineering, East China University of Technology, NanChang 330013, Jiangxi, China
| | - Chenchen Zhou
- School of Water Resources and Environmental Engineering, East China University of Technology, NanChang 330013, Jiangxi, China
| | - Zhijian Luo
- School of Water Resources and Environmental Engineering, East China University of Technology, NanChang 330013, Jiangxi, China; State Key Laboratory of Nuclear Resources and Environmental, East China University of Technology, NanChang 330013, Jiangxi, China
| | - Zhongkui Zhou
- School of Water Resources and Environmental Engineering, East China University of Technology, NanChang 330013, Jiangxi, China; State Key Laboratory of Nuclear Resources and Environmental, East China University of Technology, NanChang 330013, Jiangxi, China
| | - Jinying Chen
- School of Water Resources and Environmental Engineering, East China University of Technology, NanChang 330013, Jiangxi, China; State Key Laboratory of Nuclear Resources and Environmental, East China University of Technology, NanChang 330013, Jiangxi, China
| | - Kaixuan Sun
- School of Water Resources and Environmental Engineering, East China University of Technology, NanChang 330013, Jiangxi, China; State Key Laboratory of Nuclear Resources and Environmental, East China University of Technology, NanChang 330013, Jiangxi, China.
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