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Lu X, Zhang YY, Cheng W, Liu Y, Li Q, Li X, Dong F, Li J, Nie X. Chelating Effect of Siderophore Desferrioxamine-B on Uranyl Biomineralization Mediated by Shewanella putrefaciens. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:3974-3984. [PMID: 38306233 DOI: 10.1021/acs.est.3c05753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2024]
Abstract
In contaminated water and soil, little is known about the role and mechanism of the biometabolic molecule siderophore desferrioxamine-B (DFO) in the biogeochemical cycle of uranium due to complicated coordination and reaction networks. Here, a joint experimental and quantum chemical investigation is carried out to probe the biomineralization of uranyl (UO22+, referred to as U(VI) hereafter) induced by Shewanella putrefaciens (abbreviated as S. putrefaciens) in the presence of DFO and Fe3+ ion. The results show that the production of mineralized solids {hydrogen-uranium mica [H2(UO2)2(PO4)2·8H2O]} via S. putrefaciens binding with UO22+ is inhibited by DFO, which can both chelate preferentially UO22+ to form a U(VI)-DFO complex in solution and seize it from U(VI)-biominerals upon solvation. However, with Fe3+ ion introduced, the strong specificity of DFO binding with Fe3+ causes re-emergence of biomineralization of UO22+ {bassetite [Fe(UO2)2(PO4)2·8(H2O)]} by S. putrefaciens, owing to competitive complexation between Fe3+ and UO22+ for DFO. As DFO possesses three hydroxamic functional groups, it forms hexadentate coordination with Fe3+ and UO22+ ions via these functional groups. The stability of the Fe3+-DFO complex is much higher than that of U(VI)-DFO, resulting in some DFO-released UO22+ to be remobilized by S. putrefaciens. Our finding not only adds to the understanding of the fate of toxic U(VI)-containing substances in the environment and biogeochemical cycles in the future but also suggests the promising potential of utilizing functionalized DFO ligands for uranium processing.
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Affiliation(s)
- Xiaojing Lu
- National Collaborative Innovation Center for Nuclear Waste and Environmental Safety, Southwest University of Science and Technology, Mianyang621000, China
- School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Yang-Yang Zhang
- Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| | - Wencai Cheng
- National Collaborative Innovation Center for Nuclear Waste and Environmental Safety, Southwest University of Science and Technology, Mianyang621000, China
| | - Yingzhangyang Liu
- National Collaborative Innovation Center for Nuclear Waste and Environmental Safety, Southwest University of Science and Technology, Mianyang621000, China
| | - Qingrong Li
- National Collaborative Innovation Center for Nuclear Waste and Environmental Safety, Southwest University of Science and Technology, Mianyang621000, China
| | - Xiaoan Li
- Mianyang Central Hospital, NHC Key Laboratory of Nuclear Technology Medical Transformation, Mianyang 621000, China
| | - Faqin Dong
- National Collaborative Innovation Center for Nuclear Waste and Environmental Safety, Southwest University of Science and Technology, Mianyang621000, China
- Key Laboratory of Solid Waste Treatment and Resource Recycle of Ministry of Education, Southwest University of Science and Technology, Mianyang 621010, China
| | - Jun Li
- Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
- Department of Chemistry and Engineering Research Center of Advanced Rare-Earth Materials of Ministry of Education, Tsinghua University, Beijing 100084, China
| | - Xiaoqin Nie
- National Collaborative Innovation Center for Nuclear Waste and Environmental Safety, Southwest University of Science and Technology, Mianyang621000, China
- Key Laboratory of Solid Waste Treatment and Resource Recycle of Ministry of Education, Southwest University of Science and Technology, Mianyang 621010, China
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2
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Boussouga YA, Joseph J, Stryhanyuk H, Richnow HH, Schäfer AI. Adsorption of uranium (VI) complexes with polymer-based spherical activated carbon. WATER RESEARCH 2024; 249:120825. [PMID: 38118222 DOI: 10.1016/j.watres.2023.120825] [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: 08/11/2023] [Revised: 10/11/2023] [Accepted: 11/02/2023] [Indexed: 12/22/2023]
Abstract
Adsorption processes with carbon-based adsorbents have received substantial attention as a solution to remove uranium from drinking water. This study investigated uranium adsorption by a polymer-based spherical activated carbon (PBSAC) characterised by a uniformly smooth exterior and an extended surface of internal cavities accessible via mesopores. The static adsorption of uranium was investigated applying varying PBSAC properties and relevant solution chemistry. Spatial time-of-flight secondary ion mass spectrometry (ToF-SIMS) was employed to visualise the distribution of the different uranium species in the PBSAC. The isotherms and thermodynamics calculations revealed monolayer adsorption capacities of 28-667 mg/g and physical adsorption energies of 13-21 kJ/mol. Increasing the surface oxygen content of the PBSAC to 10 % enhanced the adsorption and reduced the equilibrium time to 2 h, while the WHO drinking water guideline of 30 µgU/L could be achieved for an initial concentration of 250 µgU/L. Uranium adsorption with PBSAC was favourable at the pH 6-8. At this pH range, uranyl carbonate complexes (UO2CO3(aq), UO2(CO3)22-, (UO2)2CO3(OH)3-) predominated in the solution, and the ToF-SIMS analysis revealed that the adsorption of these complexes occurred on the surface and inside the PBSAC due to intra-particle diffusion. For the uranyl cations (UO22+, UO2OH+) at pH 2-4, only shallow adsorption in the outermost PBSAC layers was observed. The work demonstrated the effective removal of uranium from contaminated natural water (67 µgU/L) and meeting both German (10 µgU/L) and WHO guideline concentrations. These findings also open opportunities to consider PBSAC in hybrid treatment technologies for uranium removal, for instance, from high-level radioactive waste.
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Affiliation(s)
- Youssef-Amine Boussouga
- Institute for Advanced Membrane Technology (IAMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany.
| | - James Joseph
- Institute for Advanced Membrane Technology (IAMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany
| | - Hryhoriy Stryhanyuk
- Department of Isotope Biogeochemistry, ProVIS-Centre for Chemical Microscopy, Helmholtz, Center for Environmental Research (UFZ), Leipzig, Germany
| | - Hans H Richnow
- Department of Isotope Biogeochemistry, ProVIS-Centre for Chemical Microscopy, Helmholtz, Center for Environmental Research (UFZ), Leipzig, Germany
| | - Andrea I Schäfer
- Institute for Advanced Membrane Technology (IAMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany
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3
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Stagg O, Morris K, Townsend LT, Kvashnina KO, Baker ML, Dempsey RL, Abrahamsen-Mills L, Shaw S. Sulfidation and Reoxidation of U(VI)-Incorporated Goethite: Implications for U Retention during Sub-Surface Redox Cycling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:17643-17652. [PMID: 36449568 PMCID: PMC9775214 DOI: 10.1021/acs.est.2c05314] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 11/06/2022] [Accepted: 11/08/2022] [Indexed: 06/17/2023]
Abstract
Over 60 years of nuclear activity have resulted in a global legacy of contaminated land and radioactive waste. Uranium (U) is a significant component of this legacy and is present in radioactive wastes and at many contaminated sites. U-incorporated iron (oxyhydr)oxides may provide a long-term barrier to U migration in the environment. However, reductive dissolution of iron (oxyhydr)oxides can occur on reaction with aqueous sulfide (sulfidation), a common environmental species, due to the microbial reduction of sulfate. In this work, U(VI)-goethite was initially reacted with aqueous sulfide, followed by a reoxidation reaction, to further understand the long-term fate of U species under fluctuating environmental conditions. Over the first day of sulfidation, a transient release of aqueous U was observed, likely due to intermediate uranyl(VI)-persulfide species. Despite this, overall U was retained in the solid phase, with the formation of nanocrystalline U(IV)O2 in the sulfidized system along with a persistent U(V) component. On reoxidation, U was associated with an iron (oxyhydr)oxide phase either as an adsorbed uranyl (approximately 65%) or an incorporated U (35%) species. These findings support the overarching concept of iron (oxyhydr)oxides acting as a barrier to U migration in the environment, even under fluctuating redox conditions.
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Affiliation(s)
- Olwen Stagg
- Research
Centre for Radwaste Disposal and Williamson Research Centre for Molecular
Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, ManchesterM13 9PL, U.K.
| | - Katherine Morris
- Research
Centre for Radwaste Disposal and Williamson Research Centre for Molecular
Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, ManchesterM13 9PL, U.K.
| | - Luke Thomas Townsend
- Research
Centre for Radwaste Disposal and Williamson Research Centre for Molecular
Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, ManchesterM13 9PL, U.K.
| | - Kristina O. Kvashnina
- The
Rossendorf Beamline at ESRF—The European Synchrotron, CS40220, Grenoble Cedex 938043France
- Institute
of Resource Ecology, Helmholtz Zentrum Dresden
Rossendorf (HZDR), Dresden01314, Germany
| | - Michael L. Baker
- Department
of Chemistry, The University of Manchester, ManchesterM13 9PL, U.K.
- The
University of Manchester at Harwell, The University of Manchester, Diamond Light Source, Harwell Campus, DidcotOX11 0DE, U.K.
| | - Ryan L. Dempsey
- Department
of Chemistry, The University of Manchester, ManchesterM13 9PL, U.K.
| | | | - Samuel Shaw
- Research
Centre for Radwaste Disposal and Williamson Research Centre for Molecular
Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, ManchesterM13 9PL, U.K.
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4
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Barton F, Shaw S, Morris K, Graham J, Lloyd JR. Impact and control of fouling in radioactive environments. PROGRESS IN NUCLEAR ENERGY 2022. [DOI: 10.1016/j.pnucene.2022.104215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Rogiers T, Van Houdt R, Williamson A, Leys N, Boon N, Mijnendonckx K. Molecular Mechanisms Underlying Bacterial Uranium Resistance. Front Microbiol 2022; 13:822197. [PMID: 35359714 PMCID: PMC8963506 DOI: 10.3389/fmicb.2022.822197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 01/27/2022] [Indexed: 11/16/2022] Open
Abstract
Environmental uranium pollution due to industries producing naturally occurring radioactive material or nuclear accidents and releases is a global concern. Uranium is hazardous for ecosystems as well as for humans when accumulated through the food chain, through contaminated groundwater and potable water sources, or through inhalation. In particular, uranium pollution pressures microbial communities, which are essential for healthy ecosystems. In turn, microorganisms can influence the mobility and toxicity of uranium through processes like biosorption, bioreduction, biomineralization, and bioaccumulation. These processes were characterized by studying the interaction of different bacteria with uranium. However, most studies unraveling the underlying molecular mechanisms originate from the last decade. Molecular mechanisms help to understand how bacteria interact with radionuclides in the environment. Furthermore, knowledge on these underlying mechanisms could be exploited to improve bioremediation technologies. Here, we review the current knowledge on bacterial uranium resistance and how this could be used for bioremediation applications.
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Affiliation(s)
- Tom Rogiers
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
- Center for Microbial Ecology and Technology, Ghent University, Ghent, Belgium
| | - Rob Van Houdt
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | - Adam Williamson
- Centre Etudes Nucléaires de Bordeaux Gradignan (CENBG), Bordeaux, France
| | - Natalie Leys
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | - Nico Boon
- Center for Microbial Ecology and Technology, Ghent University, Ghent, Belgium
| | - Kristel Mijnendonckx
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
- *Correspondence: Kristel Mijnendonckx,
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6
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Ostermeyer P, Bonin L, Leon‐Fernandez LF, Dominguez‐Benetton X, Hennebel T, Rabaey K. Electrified bioreactors: the next power-up for biometallurgical wastewater treatment. Microb Biotechnol 2022; 15:755-772. [PMID: 34927376 PMCID: PMC8913880 DOI: 10.1111/1751-7915.13992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/26/2021] [Accepted: 11/29/2021] [Indexed: 12/23/2022] Open
Abstract
Over the past decades, biological treatment of metallurgical wastewaters has become commonplace. Passive systems require intensive land use due to their slow treatment rates, do not recover embedded resources and are poorly controllable. Active systems however require the addition of chemicals, increasing operational costs and possibly negatively affecting safety and the environment. Electrification of biological systems can reduce the use of chemicals, operational costs, surface footprint and environmental impact when compared to passive and active technologies whilst increasing the recovery of resources and the extraction of products. Electrification of low rate applications has resulted in the development of bioelectrochemical systems (BES), but electrification of high rate systems has been lagging behind due to the limited mass transfer, electron transfer and biomass density in BES. We postulate that for high rate applications, the electrification of bioreactors, for example, through the use of electrolyzers, may herald a new generation of electrified biological systems (EBS). In this review, we evaluate the latest trends in the field of biometallurgical and microbial-electrochemical wastewater treatment and discuss the advantages and challenges of these existing treatment technologies. We advocate for future research to focus on the development of electrified bioreactors, exploring the boundaries and limitations of these systems, and their validity upon treating industrial wastewaters.
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Affiliation(s)
- Pieter Ostermeyer
- Faculty of Bioscience EngineeringCenter of Microbial Ecology and Technology (CMET)Ghent UniversityCoupure Links 653GhentB‐9000Belgium
- CAPTUREFrieda Saeysstraat 1Ghent9000Belgium
| | - Luiza Bonin
- Faculty of Bioscience EngineeringCenter of Microbial Ecology and Technology (CMET)Ghent UniversityCoupure Links 653GhentB‐9000Belgium
- CAPTUREFrieda Saeysstraat 1Ghent9000Belgium
| | - Luis Fernando Leon‐Fernandez
- Separation and Conversion TechnologyFlemish Institute for Technological Research (VITO)Boeretang 200Mol2400Belgium
| | - Xochitl Dominguez‐Benetton
- Separation and Conversion TechnologyFlemish Institute for Technological Research (VITO)Boeretang 200Mol2400Belgium
| | - Tom Hennebel
- Faculty of Bioscience EngineeringCenter of Microbial Ecology and Technology (CMET)Ghent UniversityCoupure Links 653GhentB‐9000Belgium
- Group Research and Development, Competence Area Recycling and Extraction TechnologiesUmicoreWatertorenstraat 33OlenB‐2250Belgium
| | - Korneel Rabaey
- Faculty of Bioscience EngineeringCenter of Microbial Ecology and Technology (CMET)Ghent UniversityCoupure Links 653GhentB‐9000Belgium
- CAPTUREFrieda Saeysstraat 1Ghent9000Belgium
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7
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Rogiers T, Merroun ML, Williamson A, Leys N, Houdt RV, Boon N, Mijnendonckx K. Cupriavidus metallidurans NA4 actively forms polyhydroxybutyrate-associated uranium-phosphate precipitates. JOURNAL OF HAZARDOUS MATERIALS 2022; 421:126737. [PMID: 34388922 DOI: 10.1016/j.jhazmat.2021.126737] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 06/13/2023]
Abstract
Cupriavidus metallidurans is a model bacterium to study molecular metal resistance mechanisms and its use for the bioremediation of several metals has been shown. However, its mechanisms for radionuclide resistance are unexplored. We investigated the interaction with uranium and associated cellular response to uranium for Cupriavidus metallidurans NA4. Strain NA4 actively captured 98 ± 1% of the uranium in its biomass after growing 24 h in the presence of 100 µM uranyl nitrate. TEM HAADF-EDX microscopy confirmed intracellular uranium-phosphate precipitates that were mainly associated with polyhydroxybutyrate. Furthermore, whole transcriptome sequencing indicated a complex transcriptional response with upregulation of genes encoding general stress-related proteins and several genes involved in metal resistance. More in particular, gene clusters known to be involved in copper and silver resistance were differentially expressed. This study provides further insights into bacterial interactions with and their response to uranium. Our results could be promising for uranium bioremediation purposes with the multi-metal resistant bacterium C. metallidurans NA4.
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Affiliation(s)
- Tom Rogiers
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium; Center for Microbial Ecology and Technology (CMET), UGent, Ghent, Belgium.
| | | | - Adam Williamson
- Center for Microbial Ecology and Technology (CMET), UGent, Ghent, Belgium.
| | - Natalie Leys
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium.
| | - Rob Van Houdt
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium.
| | - Nico Boon
- Center for Microbial Ecology and Technology (CMET), UGent, Ghent, Belgium.
| | - Kristel Mijnendonckx
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium.
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8
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Williamson AJ, Lloyd JR, Boothman C, Law GTW, Shaw S, Small JS, Vettese GF, Williams HA, Morris K. Biogeochemical Cycling of 99Tc in Alkaline Sediments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:15862-15872. [PMID: 34825817 DOI: 10.1021/acs.est.1c04416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
99Tc will be present in significant quantities in radioactive wastes including intermediate-level waste (ILW). The internationally favored concept for disposing of higher activity radioactive wastes including ILW is via deep geological disposal in an underground engineered facility located ∼200-1000 m deep. Typically, in the deep geological disposal environment, the subsurface will be saturated, cement will be used extensively as an engineering material, and iron will be ubiquitous. This means that understanding Tc biogeochemistry in high pH, cementitious environments is important to underpin safety case development. Here, alkaline sediment microcosms (pH 10) were incubated under anoxic conditions under "no added Fe(III)" and "with added Fe(III)" conditions (added as ferrihydrite) at three Tc concentrations (10-11, 10-6, and 10-4 mol L-1). In the 10-6 mol L-1 Tc experiments with no added Fe(III), ∼35% Tc(VII) removal occurred during bioreduction. Solvent extraction of the residual solution phase indicated that ∼75% of Tc was present as Tc(IV), potentially as colloids. In both biologically active and sterile control experiments with added Fe(III), Fe(II) formed during bioreduction and >90% Tc was removed from the solution, most likely due to abiotic reduction mediated by Fe(II). X-ray absorption spectroscopy (XAS) showed that in bioreduced sediments, Tc was present as hydrous TcO2-like phases, with some evidence for an Fe association. When reduced sediments with added Fe(III) were air oxidized, there was a significant loss of Fe(II) over 1 month (∼50%), yet this was coupled to only modest Tc remobilization (∼25%). Here, XAS analysis suggested that with air oxidation, partial incorporation of Tc(IV) into newly forming Fe oxyhydr(oxide) minerals may be occurring. These data suggest that in Fe-rich, alkaline environments, biologically mediated processes may limit Tc mobility.
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Affiliation(s)
- Adam J Williamson
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, Department of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Manchester M13 9PL, U.K
- CENBG-Équipe Radioactivité et Environnement, UMR 5797, CNRS-IN2P3/Université de Bordeaux, 19 chemin du Solarium, CS 10120, 33175 Gradignan, France
| | - Jonathan R Lloyd
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, Department of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Manchester M13 9PL, U.K
| | - Christopher Boothman
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, Department of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Manchester M13 9PL, U.K
| | - Gareth T W Law
- Radiochemistry Unit, Department of Chemistry, The University of Helsinki, Helsinki 00014, Finland
| | - Samuel Shaw
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, Department of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Manchester M13 9PL, U.K
| | - Joe S Small
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, Department of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Manchester M13 9PL, U.K
- National Nuclear Laboratory, Risley, Warrington, Cheshire WA3 6AE, U.K
| | - Gianni F Vettese
- Radiochemistry Unit, Department of Chemistry, The University of Helsinki, Helsinki 00014, Finland
| | - Heather A Williams
- Department of Nuclear Medicine, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL, U.K
| | - Katherine Morris
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, Department of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Manchester M13 9PL, U.K
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9
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You W, Peng W, Tian Z, Zheng M. Uranium bioremediation with U(VI)-reducing bacteria. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 798:149107. [PMID: 34325147 DOI: 10.1016/j.scitotenv.2021.149107] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 07/13/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
Uranium (U) pollution is an environmental hazard caused by the development of the nuclear industry. Microbial reduction of hexavalent uranium (U(VI)) to tetravalent uranium (U(IV)) reduces U solubility and mobility and has been proposed as an effective method to remediate uranium contamination. In this review, U(VI) remediation with respect to U(VI)-reducing bacteria, mechanisms, influencing factors, products, and reoxidation are systematically summarized. Reportedly, some metal- and sulfate-reducing bacteria possess excellent U(VI) reduction capability through mechanisms involving c-type cytochromes, extracellular pili, electron shuttle, or thioredoxin reduction. In situ remediation has been demonstrated as an ideal strategy for large-scale degradation of uranium contaminants than ex situ. However, U(VI) reduction efficiency can be affected by various factors, including pH, temperature, bicarbonate, electron donors, and coexisting metal ions. Furthermore, it is noteworthy that the reduction products could be reoxidized when exposed to oxygen and nitrate, inevitably compromising the remediation effects, especially for non-crystalline U(IV) with weak stability.
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Affiliation(s)
- Wenbo You
- Key Laboratory of Regional Energy Systems Optimization, Ministry of Education, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Wanting Peng
- Key Laboratory of Regional Energy Systems Optimization, Ministry of Education, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Zhichao Tian
- Key Laboratory of Regional Energy Systems Optimization, Ministry of Education, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Maosheng Zheng
- Key Laboratory of Regional Energy Systems Optimization, Ministry of Education, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China.
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10
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Townsend LT, Kuippers G, Lloyd JR, Natrajan LS, Boothman C, Mosselmans JFW, Shaw S, Morris K. Biogenic Sulfidation of U(VI) and Ferrihydrite Mediated by Sulfate-Reducing Bacteria at Elevated pH. ACS EARTH & SPACE CHEMISTRY 2021; 5:3075-3086. [PMID: 34825123 PMCID: PMC8607498 DOI: 10.1021/acsearthspacechem.1c00126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 08/17/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
Globally, the need for radioactive waste disposal and contaminated land management is clear. Here, gaining an improved understanding of how biogeochemical processes, such as Fe(III) and sulfate reduction, may control the environmental mobility of radionuclides is important. Uranium (U), typically the most abundant radionuclide by mass in radioactive wastes and contaminated land scenarios, may have its environmental mobility impacted by biogeochemical processes within the subsurface. This study investigated the fate of U(VI) in an alkaline (pH ∼9.6) sulfate-reducing enrichment culture obtained from a high-pH environment. To explore the mobility of U(VI) under alkaline conditions where iron minerals are ubiquitous, a range of conditions were tested, including high (30 mM) and low (1 mM) carbonate concentrations and the presence and absence of Fe(III). At high carbonate concentrations, the pH was buffered to approximately pH 9.6, which delayed the onset of sulfate reduction and meant that the reduction of U(VI)(aq) to poorly soluble U(IV)(s) was slowed. Low carbonate conditions allowed microbial sulfate reduction to proceed and caused the pH to fall to ∼7.5. This drop in pH was likely due to the presence of volatile fatty acids from the microbial respiration of gluconate. Here, aqueous sulfide accumulated and U was removed from solution as a mixture of U(IV) and U(VI) phosphate species. In addition, sulfate-reducing bacteria, such as Desulfosporosinus species, were enriched during development of sulfate-reducing conditions. Results highlight the impact of carbonate concentrations on U speciation and solubility in alkaline conditions, informing intermediate-level radioactive waste disposal and radioactively contaminated land management.
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Affiliation(s)
- Luke T. Townsend
- Research
Centre for Radwaste Disposal and Williamson Research Centre for Molecular
Environmental Science, Department of Earth and Environmental Sciences,
School of Natural Sciences, The University
of Manchester, Manchester M13 9PL, U.K.
| | - Gina Kuippers
- Research
Centre for Radwaste Disposal and Williamson Research Centre for Molecular
Environmental Science, Department of Earth and Environmental Sciences,
School of Natural Sciences, The University
of Manchester, Manchester M13 9PL, U.K.
| | - Jonathan R. Lloyd
- Research
Centre for Radwaste Disposal and Williamson Research Centre for Molecular
Environmental Science, Department of Earth and Environmental Sciences,
School of Natural Sciences, The University
of Manchester, Manchester M13 9PL, U.K.
| | - Louise S. Natrajan
- Centre
for Radiochemistry Research, Department of Chemistry, School of Natural
Sciences, The University of Manchester, Manchester M13 9PL, U.K.
| | - Christopher Boothman
- Research
Centre for Radwaste Disposal and Williamson Research Centre for Molecular
Environmental Science, Department of Earth and Environmental Sciences,
School of Natural Sciences, The University
of Manchester, Manchester M13 9PL, U.K.
| | - J. Frederick W. Mosselmans
- Diamond
Light Source Ltd., Diamond
House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, U.K.
| | - Samuel Shaw
- Research
Centre for Radwaste Disposal and Williamson Research Centre for Molecular
Environmental Science, Department of Earth and Environmental Sciences,
School of Natural Sciences, The University
of Manchester, Manchester M13 9PL, U.K.
| | - Katherine Morris
- Research
Centre for Radwaste Disposal and Williamson Research Centre for Molecular
Environmental Science, Department of Earth and Environmental Sciences,
School of Natural Sciences, The University
of Manchester, Manchester M13 9PL, U.K.
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11
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Fan YY, Tang Q, Li FH, Sun H, Min D, Wu JH, Li Y, Li WW, Yu HQ. Enhanced Bioreduction of Radionuclides by Driving Microbial Extracellular Electron Pumping with an Engineered CRISPR Platform. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:11997-12008. [PMID: 34378391 DOI: 10.1021/acs.est.1c03713] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Dissimilatory metal-reducing bacteria (DMRB) with extracellular electron transfer (EET) capability show great potential in bioremediating the subsurface environments contaminated by uranium through bioreduction and precipitation of hexavalent uranium [U(VI)]. However, the low EET efficiency of DMRB remains a bottleneck for their applications. Herein, we develop an engineered CRISPR platform to drive the extracellular electron pumping of Shewanella oneidensis, a representative DMRB species widely present in aquatic environments. The CRISPR platform allows for highly efficient and multiplex genome editing and rapid platform elimination post-editing in S. oneidensis. Enabled by such a platform, a genomic promoter engineering strategy (GPS) for genome-widely engineering the EET-encoding gene network was established. The production of electron conductive Mtr complex, synthesis of electron shuttle flavin, and generation of NADH as intracellular electron carrier are globally optimized and promoted, leading to a significantly enhanced EET ability. Applied to U(VI) bioreduction, the edited strains achieve up to 3.62-fold higher reduction capacity over the control. Our work endows DMRB with an enhanced ability to remediate the radionuclides-contaminated environments and provides a gene editing approach to handle the growing environmental challenges of radionuclide contaminations.
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Affiliation(s)
- Yang-Yang Fan
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Technology, University of Science and Technology of China, Hefei 230026, China
| | - Qiang Tang
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Technology, University of Science and Technology of China, Hefei 230026, China
| | - Feng-He Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Technology, University of Science and Technology of China, Hefei 230026, China
| | - Hong Sun
- School of Life Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Di Min
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Technology, University of Science and Technology of China, Hefei 230026, China
| | - Jing-Hang Wu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Technology, University of Science and Technology of China, Hefei 230026, China
| | - Yang Li
- School of Life Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Wen-Wei Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Technology, University of Science and Technology of China, Hefei 230026, China
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Technology, University of Science and Technology of China, Hefei 230026, China
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Byrd N, Lloyd JR, Small JS, Taylor F, Bagshaw H, Boothman C, Morris K. Microbial Degradation of Citric Acid in Low Level Radioactive Waste Disposal: Impact on Biomineralization Reactions. Front Microbiol 2021; 12:565855. [PMID: 33995289 PMCID: PMC8114274 DOI: 10.3389/fmicb.2021.565855] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 03/10/2021] [Indexed: 11/18/2022] Open
Abstract
Organic complexants are present in some radioactive wastes and can challenge waste disposal as they may enhance subsurface mobility of radionuclides and contaminant species via chelation. The principal sources of organic complexing agents in low level radioactive wastes (LLW) originate from chemical decontamination activities. Polycarboxylic organic decontaminants such as citric and oxalic acid are of interest as currently there is a paucity of data on their biodegradation at high pH and under disposal conditions. This work explores the biogeochemical fate of citric acid, a model decontaminant, under high pH anaerobic conditions relevant to disposal of LLW in cementitious disposal environments. Anaerobic microcosm experiments were set up, using a high pH adapted microbial inoculum from a well characterized environmental site, to explore biodegradation of citrate under representative repository conditions. Experiments were initiated at three different pH values (10, 11, and 12) and citrate was supplied as the electron donor and carbon source, under fermentative, nitrate-, Fe(III)- and sulfate- reducing conditions. Results showed that citrate was oxidized using nitrate or Fe(III) as the electron acceptor at > pH 11. Citrate was fully degraded and removed from solution in the nitrate reducing system at pH 10 and pH 11. Here, the microcosm pH decreased as protons were generated during citrate oxidation. In the Fe(III)-reducing systems, the citrate removal rate was slower than in the nitrate reducing systems. This was presumably as Fe(III)-reduction consumes fewer moles of citrate than nitrate reduction for the same molar concentrations of electron acceptor. The pH did not change significantly in the Fe(III)-reducing systems. Sulfate reduction only occurred in a single microcosm at pH 10. Here, citrate was fully removed from solution, alongside ingrowth of acetate and formate, likely fermentation products. The acetate and lactate were subsequently used as electron donors during sulfate-reduction and there was an associated decrease in solution pH. Interestingly, in the Fe(III) reducing experiments, Fe(II) ingrowth was observed at pH values recorded up to 11.7. Here, TEM analysis of the resultant solid Fe-phase indicated that nanocrystalline magnetite formed as an end product of Fe(III)-reduction under these extreme conditions. PCR-based high-throughput 16S rRNA gene sequencing revealed that bacteria capable of nitrate Fe(III) and sulfate reduction became enriched in the relevant, biologically active systems. In addition, some fermentative organisms were identified in the Fe(III)- and sulfate-reducing systems. The microbial communities present were consistent with expectations based on the geochemical data. These results are important to improve long-term environmental safety case development for cementitious LLW waste disposal.
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Affiliation(s)
- Natalie Byrd
- Department of Earth and Environmental Sciences, Research Centre for Radwaste Disposal and Williamson Research Centre, The University of Manchester, Manchester, United Kingdom
| | - Jonathan R Lloyd
- Department of Earth and Environmental Sciences, Research Centre for Radwaste Disposal and Williamson Research Centre, The University of Manchester, Manchester, United Kingdom
| | - Joe S Small
- Department of Earth and Environmental Sciences, Research Centre for Radwaste Disposal and Williamson Research Centre, The University of Manchester, Manchester, United Kingdom.,National Nuclear Laboratory, Warrington, United Kingdom
| | - Frank Taylor
- Low Level Waste Repository Ltd., Seascale, United Kingdom
| | - Heath Bagshaw
- School of Engineering, The University of Liverpool, Liverpool, United Kingdom
| | - Christopher Boothman
- Department of Earth and Environmental Sciences, Research Centre for Radwaste Disposal and Williamson Research Centre, The University of Manchester, Manchester, United Kingdom
| | - Katherine Morris
- Department of Earth and Environmental Sciences, Research Centre for Radwaste Disposal and Williamson Research Centre, The University of Manchester, Manchester, United Kingdom
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Kuippers G, Morris K, Townsend LT, Bots P, Kvashnina K, Bryan ND, Lloyd JR. Biomineralization of Uranium-Phosphates Fueled by Microbial Degradation of Isosaccharinic Acid (ISA). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:4597-4606. [PMID: 33755437 DOI: 10.1021/acs.est.0c03594] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Geological disposal is the globally preferred long-term solution for higher activity radioactive wastes (HAW) including intermediate level waste (ILW). In a cementitious disposal system, cellulosic waste items present in ILW may undergo alkaline hydrolysis, producing significant quantities of isosaccharinic acid (ISA), a chelating agent for radionuclides. Although microbial degradation of ISA has been demonstrated, its impact upon the fate of radionuclides in a geological disposal facility (GDF) is a topic of ongoing research. This study investigates the fate of U(VI) in pH-neutral, anoxic, microbial enrichment cultures, approaching conditions similar to the far field of a GDF, containing ISA as the sole carbon source, and elevated phosphate concentrations, incubated both (i) under fermentation and (ii) Fe(III)-reducing conditions. In the ISA-fermentation experiment, U(VI) was precipitated as insoluble U(VI)-phosphates, whereas under Fe(III)-reducing conditions, the majority of the uranium was precipitated as reduced U(IV)-phosphates, presumably formed via enzymatic reduction mediated by metal-reducing bacteria, including Geobacter species. Overall, this suggests the establishment of a microbially mediated "bio-barrier" extending into the far field geosphere surrounding a GDF is possible and this biobarrier has the potential to evolve in response to GDF evolution and can have a controlling impact on the fate of radionuclides.
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Affiliation(s)
- Gina Kuippers
- Research Centre for Radwaste Disposal & Williamson Research Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Katherine Morris
- Research Centre for Radwaste Disposal & Williamson Research Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Luke T Townsend
- Research Centre for Radwaste Disposal & Williamson Research Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Pieter Bots
- Research Centre for Radwaste Disposal & Williamson Research Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
- Civil and Environmental Engineering, University of Strathclyde, Glasgow, G11XQ, U.K
| | - Kristina Kvashnina
- The Rossendorf Beamline at ESRF-The European Synchrotron, CS40220, 38043 Grenoble Cedex 9, France
- Helmholtz Zentrum Dresden-Rossendorf (HZDR), Institute of Resource Ecology, P.O. Box 510119, 01314 Dresden, Germany
| | - Nicholas D Bryan
- National Nuclear Laboratory Limited, Chadwick House, Warrington Road, Birchwood Park, Warrington, WA3 6AE, U.K
| | - Jonathan R Lloyd
- Research Centre for Radwaste Disposal & Williamson Research Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
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14
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Ruiz-Fresneda MA, Gomez-Bolivar J, Delgado-Martin J, Abad-Ortega MDM, Guerra-Tschuschke I, Merroun ML. The Bioreduction of Selenite under Anaerobic and Alkaline Conditions Analogous to Those Expected for a Deep Geological Repository System. Molecules 2019; 24:molecules24213868. [PMID: 31717840 PMCID: PMC6865132 DOI: 10.3390/molecules24213868] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 10/21/2019] [Accepted: 10/22/2019] [Indexed: 12/23/2022] Open
Abstract
The environmental conditions for the planned geological disposal of radioactive waste —including hyper-alkaline pH, radiation or anoxia—are expected to be extremely harsh for microbial activity. However, it is thought that microbial communities will develop in these repositories, and this would have implications for geodisposal integrity and the control of radionuclide migration through the surrounding environment. Nuclear waste contains radioactive isotopes of selenium (Se) such as 79Se, which has been identified as one of the main radionuclides in a geodisposal system. Here, we use the bacterial species Stenotrophomonas bentonitica, isolated from bentonites serving as an artificial barrier reference material in repositories, to study the reduction of selenite (SeIV) under simulated geodisposal conditions. This bacterium is able to reduce toxic SeIV anaerobically from a neutral to alkaline initial pH (up to pH 10), thereby producing elemental selenium (Se0) nanospheres and nanowires. A transformation process from amorphous Se (a-Se) nanospheres to trigonal Se (t-Se) nanowires, through the formation of monoclinic Se (m-Se) aggregates as an intermediate step, is proposed. The lesser solubility of Se0 and t-Se makes S. bentonitica a potential candidate to positively influence the security of a geodisposal system, most probably with lower efficiency rates than those obtained aerobically.
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Affiliation(s)
- Miguel Angel Ruiz-Fresneda
- Department of Microbiology, University of Granada, 18071 Granada, Spain; (J.G.-B.); (J.D.-M.); (M.L.M.)
- Correspondence:
| | - Jaime Gomez-Bolivar
- Department of Microbiology, University of Granada, 18071 Granada, Spain; (J.G.-B.); (J.D.-M.); (M.L.M.)
| | - Josemaria Delgado-Martin
- Department of Microbiology, University of Granada, 18071 Granada, Spain; (J.G.-B.); (J.D.-M.); (M.L.M.)
| | - Maria del Mar Abad-Ortega
- Centro de Instrumentación Científica (CIC), University of Granada, 18071 Granada, Spain; (M.d.M.A.-O.); (I.G.-T.)
| | - Isabel Guerra-Tschuschke
- Centro de Instrumentación Científica (CIC), University of Granada, 18071 Granada, Spain; (M.d.M.A.-O.); (I.G.-T.)
| | - Mohamed Larbi Merroun
- Department of Microbiology, University of Granada, 18071 Granada, Spain; (J.G.-B.); (J.D.-M.); (M.L.M.)
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15
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Lakaniemi AM, Douglas GB, Kaksonen AH. Engineering and kinetic aspects of bacterial uranium reduction for the remediation of uranium contaminated environments. JOURNAL OF HAZARDOUS MATERIALS 2019; 371:198-212. [PMID: 30851673 DOI: 10.1016/j.jhazmat.2019.02.074] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 01/29/2019] [Accepted: 02/20/2019] [Indexed: 06/09/2023]
Abstract
Biological reduction of soluble uranium from U(VI) to insoluble U(IV) coupled to the oxidation of an electron donor (hydrogen or organic compounds) is a potentially cost-efficient way to reduce the U concentrations in contaminated waters to below regulatory limits. A variety of microorganisms originating from both U contaminated and non-contaminated environments have demonstrated U(VI) reduction capacity under anaerobic conditions. Bioreduction of U(VI) is considered especially promising for in situ remediation, where the activity of indigenous microorganisms is stimulated by supplying a suitable electron donor to the subsurface to contain U contamination to a specific location in a sparingly soluble form. Less studied microbial biofilm-based bioreactors and bioelectrochemical systems have also shown potential for efficient U(VI) reduction to remove U from contaminated water streams. This review compares the advantages and challenges of U(VI)-reducing in situ remediation processes, bioreactors and bioelectrochemical systems. In addition, the current knowledge of U(VI) bioreduction mechanisms and factors affecting U(VI) reduction kinetics (e.g. pH, temperature, and the chemical composition of the contaminated water) are discussed, as both of these aspects are important in designing efficient remediation processes.
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Affiliation(s)
- Aino-Maija Lakaniemi
- Tampere University, Faculty of Engineering and Natural Sciences, P.O. Box 541, FI- 33104, Tampere University, Finland; CSIRO Land and Water, 147 Underwood Avenue, Floreat, Western Australia, 6014, Australia.
| | - Grant B Douglas
- CSIRO Land and Water, 147 Underwood Avenue, Floreat, Western Australia, 6014, Australia
| | - Anna H Kaksonen
- CSIRO Land and Water, 147 Underwood Avenue, Floreat, Western Australia, 6014, Australia
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16
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Vijayaraghavan R, Ellappan V, Dharmar P, Lakshmanan U. Preferential adsorption of uranium by functional groups of the marine unicellular cyanobacterium Synechococcus elongatus BDU130911. 3 Biotech 2018; 8:170. [PMID: 29556424 DOI: 10.1007/s13205-018-1167-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 02/10/2018] [Indexed: 10/17/2022] Open
Abstract
This study reports the surface interaction of the chemically modified marine unicellular cyanobacterium Synechococcus elongatus BDU130911 with uranium. The selective functional groups of the control (dead biomass) for binding with uranium in unicellular marine cyanobacteria were identified as carboxyl groups. The adsorption capacity of the biomass in a 1 mM uranium solution was found to be 92% in the control, 85% in the amine-blocked treatments, and 20% in the carboxyl-blocked treatments. The Langmuir isotherm provided a good fit to the data, suggesting a monolayer of uranium adsorption on all the tested biomass. The functional groups involved in the adsorption of uranium by the control and modified biomass were assessed by Fourier transform infrared spectroscopy, energy dispersive X-ray fluorescence and X-ray diffractive analysis. The results of this study identify, carboxyl groups as the dominant anionic functional group involved in uranium adsorption, which validates an ionic interaction between the biomass and uranium, a cationic metal.
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17
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Unusual Versatility of the Filamentous, Diazotrophic Cyanobacterium Anabaena torulosa Revealed for Its Survival during Prolonged Uranium Exposure. Appl Environ Microbiol 2017; 83:AEM.03356-16. [PMID: 28258135 DOI: 10.1128/aem.03356-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 02/19/2017] [Indexed: 11/20/2022] Open
Abstract
Reports on interactions between cyanobacteria and uranyl carbonate are rare. Here, we present an interesting succession of the metabolic responses employed by a marine, filamentous, diazotrophic cyanobacterium, Anabaena torulosa for its survival following prolonged exposure to uranyl carbonate extending up to 384 h at pH 7.8 under phosphate-limited conditions. The cells sequestered uranium (U) within polyphosphates on initial exposure to 100 μM uranyl carbonate for 24 to 28 h. Further incubation until 120 h resulted in (i) significant degradation of cellular polyphosphates causing extensive chlorosis and cell lysis, (ii) akinete differentiation followed by (iii) extracellular uranyl precipitation. X-ray diffraction (XRD) analysis, fluorescence spectroscopy, X-ray absorption near edge structure (XANES), and extended X-ray absorption fine structure (EXAFS) spectroscopy established the identity of the bioprecipitated uranium as a U(VI) autunite-type mineral, which settled at the bottom of the vessel. Surprisingly, A. torulosa cells resurfaced as small green flakes typical of actively growing colonies on top of the test solutions within 192 to 240 h of U exposure. A consolidated investigation using kinetics, microscopy, and physiological and biochemical analyses suggested a role of inducible alkaline phosphatase activity of cell aggregates/akinetes in facilitating the germination of akinetes leading to substantial regeneration of A. torulosa by 384 h of uranyl incubation. The biomineralized uranium appeared to be stable following cell regeneration. Altogether, our results reveal novel insights into the survival mechanism adopted by A. torulosa to resist sustained uranium toxicity under phosphate-limited oxic conditions.IMPORTANCE Long-term effects of uranyl exposure in cyanobacteria under oxic phosphate-limited conditions have been inadequately explored. We conducted a comprehensive examination of the metabolic responses displayed by a marine cyanobacterium, Anabaena torulosa, to cope with prolonged exposure to uranyl carbonate at pH 7.8 under phosphate limitation. Our results highlight distinct adaptive mechanisms harbored by this cyanobacterium that enabled its natural regeneration following extensive cell lysis and uranium biomineralization under sustained uranium exposure. Such complex interactions between environmental microbes such as Anabaena torulosa and uranium over a broader time range advance our understanding on the impact of microbial processes on uranium biogeochemistry.
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Smith SL, Boothman C, Williams HA, Ellis BL, Wragg J, West JM, Lloyd JR. Microbial impacts on 99mTc migration through sandstone under highly alkaline conditions relevant to radioactive waste disposal. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 575:485-495. [PMID: 27751688 DOI: 10.1016/j.scitotenv.2016.08.126] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 08/09/2016] [Accepted: 08/18/2016] [Indexed: 06/06/2023]
Abstract
Geological disposal of intermediate level radioactive waste in the UK is planned to involve the use of cementitious materials, facilitating the formation of an alkali-disturbed zone within the host rock. The biogeochemical processes that will occur in this environment, and the extent to which they will impact on radionuclide migration, are currently poorly understood. This study investigates the impact of biogeochemical processes on the mobility of the radionuclide technetium, in column experiments designed to be representative of aspects of the alkali-disturbed zone. Results indicate that microbial processes were capable of inhibiting 99mTc migration through columns, and X-ray radiography demonstrated that extensive physical changes had occurred to the material within columns where microbiological activity had been stimulated. The utilisation of organic acids under highly alkaline conditions, generating H2 and CO2, may represent a mechanism by which microbial processes may alter the hydraulic conductivity of a geological environment. Column sediments were dominated by obligately alkaliphilic H2-oxidising bacteria, suggesting that the enrichment of these bacteria may have occurred as a result of H2 generation during organic acid metabolism. The results from these experiments show that microorganisms are able to carry out a number of processes under highly alkaline conditions that could potentially impact on the properties of the host rock surrounding a geological disposal facility for intermediate level radioactive waste.
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Affiliation(s)
- Sarah L Smith
- Research Centre for Radwaste and Decommissioning & Williamson Research Centre for Molecular Environmental Science, School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Williamson Building, Oxford Road, Manchester M13 9PL, United Kingdom; British Geological Survey, Environmental Science Centre, Nicker Hill, Keyworth, Nottingham NG12 5GG, United Kingdom
| | - Christopher Boothman
- Research Centre for Radwaste and Decommissioning & Williamson Research Centre for Molecular Environmental Science, School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Williamson Building, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Heather A Williams
- Department of Nuclear Medicine, Manchester Royal Infirmary, Oxford Road, M13 9WL, United Kingdom
| | - Beverly L Ellis
- Department of Nuclear Medicine, Manchester Royal Infirmary, Oxford Road, M13 9WL, United Kingdom
| | - Joanna Wragg
- British Geological Survey, Environmental Science Centre, Nicker Hill, Keyworth, Nottingham NG12 5GG, United Kingdom
| | - Julia M West
- British Geological Survey, Environmental Science Centre, Nicker Hill, Keyworth, Nottingham NG12 5GG, United Kingdom
| | - Jonathan R Lloyd
- Research Centre for Radwaste and Decommissioning & Williamson Research Centre for Molecular Environmental Science, School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Williamson Building, Oxford Road, Manchester M13 9PL, United Kingdom
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19
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A highly diverse, desert-like microbial biocenosis on solar panels in a Mediterranean city. Sci Rep 2016; 6:29235. [PMID: 27378552 PMCID: PMC4932501 DOI: 10.1038/srep29235] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 06/13/2016] [Indexed: 12/03/2022] Open
Abstract
Microorganisms colonize a wide range of natural and artificial environments although there are hardly any data on the microbial ecology of one the most widespread man-made extreme structures: solar panels. Here we show that solar panels in a Mediterranean city (Valencia, Spain) harbor a highly diverse microbial community with more than 500 different species per panel, most of which belong to drought-, heat- and radiation-adapted bacterial genera, and sun-irradiation adapted epiphytic fungi. The taxonomic and functional profiles of this microbial community and the characterization of selected culturable bacteria reveal the existence of a diverse mesophilic microbial community on the panels’ surface. This biocenosis proved to be more similar to the ones inhabiting deserts than to any human or urban microbial ecosystem. This unique microbial community shows different day/night proteomic profiles; it is dominated by reddish pigment- and sphingolipid-producers, and is adapted to withstand circadian cycles of high temperatures, desiccation and solar radiation.
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20
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Yan W, Wang H, Jing C. Adhesion of Shewanella oneidensis MR-1 to Goethite: A Two-Dimensional Correlation Spectroscopic Study. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:4343-4349. [PMID: 27029565 DOI: 10.1021/acs.est.6b00066] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Bacterial adhesion to mineral surfaces is an important but underappreciated process. To decipher the molecular level process and mechanism, the adhesion of Shewanella oneidensis MR-1 cells to goethite was investigated using flow-cell attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy coupled with two-dimensional correlation spectroscopy (2D-COS) analysis. The FTIR results indicate that bacterial phosphate-moieties play an important role in the formation of mono- and bidentate inner-sphere complexes, whereas carboxylic groups on cell surface only have a minor contribution to its adhesion. The 2D-COS analysis in short-term (0-120 min) and long-term (2-18 h) stages reveal that the adhesion process was in the following sequence: change in H-bonds of proteins on cell surfaces > formation of monodentate inner-sphere surface complexes > formation of outer-sphere surface complexes > transformation of protein secondary structure on cell surfaces > formation of additional bridging bidentate surface complexes. In addition, the adhesion of MR-1 cells on goethite was pH dependent due to pH impacts on the cell structure and the interface charge. The in situ ATR-FTIR integrated with 2D-COS analysis highlights its great potential in exploring complex surface reactions with microbes involved. These results improve our understanding of microbe-mineral interactions at the molecular level and have significant implications for a series of biogeochemical processes.
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Affiliation(s)
- Wei Yan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
| | - Hongbo Wang
- School of Municipal and Environmental Engineering, Shandong Jianzhu University , Jinan 250101, China
| | - Chuanyong Jing
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
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21
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Brookshaw DR, Pattrick RAD, Bots P, Law GTW, Lloyd JR, Mosselmans JFW, Vaughan DJ, Dardenne K, Morris K. Redox Interactions of Tc(VII), U(VI), and Np(V) with Microbially Reduced Biotite and Chlorite. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:13139-13148. [PMID: 26488884 DOI: 10.1021/acs.est.5b03463] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Technetium, uranium, and neptunium are contaminants that cause concern at nuclear facilities due to their long half-life, environmental mobility, and radiotoxicity. Here we investigate the impact of microbial reduction of Fe(III) in biotite and chlorite and the role that this has in enhancing mineral reactivity toward soluble TcO4(-), UO2(2+), and NpO2(+). When reacted with unaltered biotite and chlorite, significant sorption of U(VI) occurred in low carbonate (0.2 mM) buffer, while U(VI), Tc(VII), and Np(V) showed low reactivity in high carbonate (30 mM) buffer. On reaction with the microbially reduced minerals, all radionuclides were removed from solution with U(VI) reactivity influenced by carbonate. Analysis by X-ray absorption spectroscopy (XAS) confirmed reductive precipitation to poorly soluble U(IV) in low carbonate conditions and both Tc(VII) and Np(V) in high carbonate buffer were also fully reduced to poorly soluble Tc(IV) and Np(IV) phases. U(VI) reduction was inhibited under high carbonate conditions. Furthermore, EXAFS analysis suggested that in the reaction products, Tc(IV) was associated with Fe, Np(IV) formed nanoparticulate NpO2, and U(IV) formed nanoparticulate UO2 in chlorite and was associated with silica in biotite. Overall, microbial reduction of the Fe(III) associated with biotite and chlorite primed the minerals for reductive scavenging of radionuclides: this has clear implications for the fate of radionuclides in the environment.
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Affiliation(s)
- Diana R Brookshaw
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, School of Earth, Atmospheric and Environmental Sciences, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - Richard A D Pattrick
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, School of Earth, Atmospheric and Environmental Sciences, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - Pieter Bots
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, School of Earth, Atmospheric and Environmental Sciences, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - Gareth T W Law
- Centre for Radiochemistry Research, School of Chemistry, The University of Manchester , Manchester M13 9PL, United Kingdom
| | - Jonathan R Lloyd
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, School of Earth, Atmospheric and Environmental Sciences, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - J Fredrick W Mosselmans
- Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - David J Vaughan
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, School of Earth, Atmospheric and Environmental Sciences, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - Kathy Dardenne
- Karlsruhe Institute of Technology, Institut fur Nukleare Entsorgung , D-76021 Karlsruhe, Baden-Württemberg, Germany
| | - Katherine Morris
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, School of Earth, Atmospheric and Environmental Sciences, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
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