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Lian G, An Y, Sun J, Yang B, Shen Z. Effects and driving mechanisms of bioremediation on groundwater after the neutral in situ leaching of uranium. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174406. [PMID: 38964395 DOI: 10.1016/j.scitotenv.2024.174406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 06/04/2024] [Accepted: 06/29/2024] [Indexed: 07/06/2024]
Abstract
The remediation of groundwater subject to in situ leaching (ISL) for uranium mining has raised extensive concerns in uranium mill and milling. This study conducted bioremediation through biostimulation and bioaugmentation to the groundwater in an area in northern China that was contaminated due to uranium mining using the CO2 + O2 neutral ISL (NISL) technology. It identified the dominant controlling factors and mechanisms driving bioremediation. Findings indicate that microorganisms can reduce the uranium concentration in groundwater subject to NISL uranium mining to its normal level. After 120 days of bioaugmentation, the uranium concentration in the contaminated groundwater fell to 0.36 mg/L, achieving a remediation efficiency of 91.26 %. Compared with biostimulation, bioaugmentation shortened the remediation timeframe by 30 to 60 days while maintaining roughly the same remediation efficiency. For groundwater remediation using indigenous microbial inoculants, initial uranium concentration and low temperatures (below 15 °C) emerge as the dominant factors influencing the bioremediation performance and duration. In settings with high carbonate concentrations, bioremediation involved the coupling of multiple processes including bioreduction, biotransformation, biomineralization, and biosorption, with bioreduction assuming a predominant role. Post-bioremediation, the relative abundances of reducing microbes Desulfosporosinus and Sulfurospirillum in groundwater increased significantly by 10.56 % and 6.91 %, respectively, offering a sustainable, stable biological foundation for further bioremediation of groundwater.
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Affiliation(s)
- Guoxi Lian
- State Key Laboratory of Water Environment, School of Environment, Beijing Normal University, Beijing 100875, China; Nuclear and Radiation Safety Center, Ministry of Ecology and Environment, Beijing 100082, China
| | - Yifu An
- The Fourth Research and Design Engineering Corporation of CNNC, Shijiazhuang 050021, China
| | - Juan Sun
- The Fourth Research and Design Engineering Corporation of CNNC, Shijiazhuang 050021, China
| | - Bing Yang
- The Fourth Research and Design Engineering Corporation of CNNC, Shijiazhuang 050021, China
| | - Zhenyao Shen
- State Key Laboratory of Water Environment, School of Environment, Beijing Normal University, Beijing 100875, China.
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Tang Y, Chen X, Hou L, He J, Sha A, Zou L, Peng L, Li Q. Effects of uranium mining on the rhizospheric bacterial communities of three local plants on the Qinghai-Tibet Plateau. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024:10.1007/s11356-024-34335-1. [PMID: 39044055 DOI: 10.1007/s11356-024-34335-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 07/05/2024] [Indexed: 07/25/2024]
Abstract
In this study, we used 16S high-throughput sequencing to investigate the effects of uranium mining on the rhizospheric bacterial communities and functions of three local plant species, namely, Artemisia frigida, Acorus tatarionwii Schott., and Salix oritrepha Schneid. The results showed that uranium mining significantly reduced the diversity of rhizospheric bacteria in the three local plant species, including the Shannon index and Simpson index (P < 0.05). Interestingly, we found that Sphingomonas and Pseudotrichobacter were enriched in the rhizosphere soil of the three local plants from uranium mining areas, indicating their important ecological role. The three plants were enriched in various dominant rhizospheric bacterial populations in the uranium mining area, including Vicinamidobacteriaceae, Nocardioides, and Gaiella, which may be related to the unique microecological environment of the plant rhizosphere. The rhizospheric bacterial community of A. tatarionwii plants from tailings and open-pit mines also showed a certain degree of differentiation, indicating that uranium mining is the main factor driving the differentiation of plant rhizosphere soil communities on the plateau. Functional prediction revealed that rhizospheric bacteria from different plants have developed different functions to cope with stress caused by uranium mining activities, including enhancing the translational antagonist Rof, the translation initiation factor 2B subunit, etc. This study explores for the first time the impact of plateau uranium mining activities on the rhizosphere microecology of local plants, promoting the establishment of effective soil microecological health monitoring indicators, and providing a reference for further soil pollution remediation in plateau uranium mining areas.
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Affiliation(s)
- Yuanmou Tang
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu, Sichuan, China
| | - Xiaodie Chen
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu, Sichuan, China
| | - Liming Hou
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Jing He
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu, Sichuan, China
| | - Ajia Sha
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu, Sichuan, China
| | - Liang Zou
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu, Sichuan, China
| | - Lianxin Peng
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu, Sichuan, China
| | - Qiang Li
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu, Sichuan, China.
- School of Food and Biological Engineering, Chengdu University, Chengdu, 610106, Sichuan, China.
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Rastkhah E, Fatemi F, Maghami P. Optimizing the Metal Bioreduction Process in Recombinant Shewanella azerbaijanica Bacteria: A Novel Approach via mtrC Gene Cloning and Nitrate-Reducing Pathway Destruction. Mol Biotechnol 2023:10.1007/s12033-023-00920-x. [PMID: 37917324 DOI: 10.1007/s12033-023-00920-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 09/22/2023] [Indexed: 11/04/2023]
Abstract
Environmental pollution is growing every day in terms of the increase in population, industrialization, and urbanization. Shewanella azerbaijanica is introduced as a highly potent bacterium in metal bioremediation. The mtrC gene was selected as a cloning target to improve electron flux chains in the EET (extracellular electron transfer) pathway. Using the SDM (site-directed mutagenesis) technique, the unique gene assembly featured the mtrC gene sandwiched between two napD/B genes to disrupt the nitrate reduction pathway, which serves as the primary metal reduction competitor. Shew-mtrC gene construction was transferred to expression plasmid pET28a (+) in the expression host bacteria (E. coli BL21 and S. azerbaijanica), in pUC57, cloning plasmid, which was transferred to the cloning host bacteria E. coli Top10 and S. azerbaijanica. All cloning procedures (i.e., synthesis, insertion, transformation, cloning, and protein expression) were verified and confirmed by precise tests. ATR-FTIR analysis, CD, western blotting, affinity chromatography, SDS-PAGE, and other techniques were used to confirm the expression and structure of the MtrC protein. The genome sequence and primers were designed according to the submitted Shewanella oneidensis MR-1 genome, the most similar bacteria to this native species. The performance of recombinant S. azerbaijanica bacterium in metal bioremediation, as sustainable strategy, has to be verified by more research.
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Affiliation(s)
- Elham Rastkhah
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Faezeh Fatemi
- Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, Tehran, Iran.
| | - Parvaneh Maghami
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
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Effects of UV stress on Shewanella azerbaijanica bioremediation response. RADIOCHIM ACTA 2022. [DOI: 10.1515/ract-2022-0059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Abstract
Shewanella azerbaijanica roles as a live electrode, passing electrons from electron donors to electron acceptors, to gain energy from the extracellular electron transfer (EET) pathway. The present study, considered the quantitative expressions of the major EET reductase genes (mtr cluster), together with uranium removal, live-cell counting, and spectrophotometry in UV-C treated bacteria (0, 60, 120 and 180 s). The simultaneous decline in the uranium removal and cell counting, along with major mtr gene expression patterns (mtrABDEF), approved the negative effects of UV-C radiation on uranium bioreduction in S. azerbaijanica. Uranium removal and cell counting decreased to 25.49% and 0.45 × 109 cells/mL in the 180s UV-C treated sample, respectively at 2 mM uranium concentration, while no decline trend found in 0.5 mM for the counted cells and uranium removal tests. No considerable expression of omcA and omcB (mtrC) genes were traced due to spontaneous mutagenesis during the in vitro serial passages, proposing a novel alternative EET pathway in S. azerbaijanica during uranium bioreduction process. The results could pave the way for further researches to modify the bioremediation process through genetic manipulation.
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