1
|
Ruiz-Fresneda MA, Martinez-Moreno MF, Povedano-Priego C, Morales-Hidalgo M, Jroundi F, Merroun ML. Impact of microbial processes on the safety of deep geological repositories for radioactive waste. Front Microbiol 2023; 14:1134078. [PMID: 37007474 PMCID: PMC10062484 DOI: 10.3389/fmicb.2023.1134078] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 02/27/2023] [Indexed: 03/18/2023] Open
Abstract
To date, the increasing production of radioactive waste due to the extensive use of nuclear power is becoming a global environmental concern for society. For this reason, many countries have been considering the use of deep geological repositories (DGRs) for the safe disposal of this waste in the near future. Several DGR designs have been chemically, physically, and geologically well characterized. However, less is known about the influence of microbial processes for the safety of these disposal systems. The existence of microorganisms in many materials selected for their use as barriers for DGRs, including clay, cementitious materials, or crystalline rocks (e.g., granites), has previously been reported. The role that microbial processes could play in the metal corrosion of canisters containing radioactive waste, the transformation of clay minerals, gas production, and the mobility of the radionuclides characteristic of such residues is well known. Among the radionuclides present in radioactive waste, selenium (Se), uranium (U), and curium (Cm) are of great interest. Se and Cm are common components of the spent nuclear fuel residues, mainly as 79Se isotope (half-life 3.27 × 105 years), 247Cm (half-life: 1.6 × 107 years) and 248Cm (half-life: 3.5 × 106 years) isotopes, respectively. This review presents an up-to-date overview about how microbes occurring in the surroundings of a DGR may influence their safety, with a particular focus on the radionuclide-microbial interactions. Consequently, this paper will provide an exhaustive understanding about the influence of microorganisms in the safety of planned radioactive waste repositories, which in turn might improve their implementation and efficiency.
Collapse
|
2
|
Krawczyk-Bärsch E, Ramtke J, Drobot B, Müller K, Steudtner R, Kluge S, Hübner R, Raff J. Peptidoglycan as major binding motif for Uranium bioassociation on Magnetospirillum magneticum AMB-1 in contaminated waters. JOURNAL OF HAZARDOUS MATERIALS 2022; 437:129376. [PMID: 35897184 DOI: 10.1016/j.jhazmat.2022.129376] [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: 03/25/2022] [Revised: 05/30/2022] [Accepted: 06/11/2022] [Indexed: 06/15/2023]
Abstract
The U(VI) bioassociation on Magnetospirillum magneticum AMB-1 cells was investigated using a multidisciplinary approach combining wet chemistry, microscopy, and spectroscopy methods to provide deeper insight into the interaction of U(VI) with bioligands of Gram-negative bacteria for a better molecular understanding. Our findings suggest that the cell wall plays a prominent role in the bioassociation of U(VI). In time-dependent bioassociation studies, up to 95 % of the initial U(VI) was removed from the suspension and probably bound on the cell wall within the first hours due to the high removal capacity of predominantly alive Magnetospirillum magneticum AMB-1 cells. PARAFAC analysis of TRLFS data highlights that peptidoglycan is the most important ligand involved, showing a stable immobilization of U(VI) over a wide pH range with the formation of three characteristic species. In addition, in-situ ATR FT-IR reveals the predominant strong binding to carboxylic functionalities. At higher pH polynuclear species seem to play an important role. This comprehensive molecular study may initiate in future new remediation strategies on effective immobilization of U(VI). In combination with the magnetic properties of the bacteria, a simple technical water purification process could be realized not only for U(VI), but probably also for other heavy metals.
Collapse
Affiliation(s)
- Evelyn Krawczyk-Bärsch
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany.
| | - Justus Ramtke
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany; University of Applied Sciences Zittau/Görlitz, Faculty of Natural and Environmental Sciences, Theodor-Körner, Allee 8, 02763 Zittau, Germany
| | - Björn Drobot
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Katharina Müller
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Robin Steudtner
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Sindy Kluge
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - René Hübner
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Johannes Raff
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany
| |
Collapse
|
3
|
Moll H, Barkleit A, Frost L, Raff J. Curium(III) speciation in the presence of microbial cell wall components. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 227:112887. [PMID: 34649137 DOI: 10.1016/j.ecoenv.2021.112887] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/06/2021] [Accepted: 10/07/2021] [Indexed: 06/13/2023]
Abstract
Trivalent actinides such as Cm(III) are able to strongly interact with microbes and especially with bacterial cell walls. However, detailed knowledge of the influence of different cell wall components is somewhat lacking. For this investigation, we studied the formation of aqueous Cm(III) complexes with cell wall components (e.g., lipopolysaccharide, peptidoglycan, and plasma membranes) using time-resolved laser-induced fluorescence spectroscopy (TRLFS). For all systems, two specific Cm(III) complexes with the biomacromolecules were observed as a function of pH. Specifically, Cm(III) was found to bind to phosphate and carboxyl groups present in the structure of the biomacromolecules. Stability constants and luminescence parameters of the specific Cm(III) complexes were determined and are presented. The pH of the surrounding aqueous solution, the plasma membrane concentration, and proteins included in the crude plasma membrane fraction were found to significantly impact the complexation of Cm(III). The Cm(III) luminescence spectra with plasma membranes, cell wall polymers, as well as Gram-negative (Sporomusa sp. MT-2.99 and Pseudomonas fluorescens) and Gram-positive (Paenibacillus sp. MT-2.2) bacteria will be explained by linear combination fitting using the investigated components.
Collapse
Affiliation(s)
- Henry Moll
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany.
| | - Astrid Barkleit
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Laura Frost
- JEN Jülicher Entsorgungsgesellschaft für Nuklearanlagen mbH, Wilhelm - Johnen - Straße, 52428 Jülich, Germany
| | - Johannes Raff
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany
| |
Collapse
|
4
|
Huclier-Markai S, Alliot C, Mazza M, Reiller PE. Complexation of europium(III) with exopolysaccharides from a marine bacterium envisaged as luminescent probe in a theranostic approach. Dalton Trans 2021; 50:17215-17227. [PMID: 34783812 DOI: 10.1039/d1dt03288g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Exopolysaccharide (EPS) derivatives, produced by Alteromonas infernus bacterium, showed anti-metastatic properties in osteosarcoma (bone tumor). These EPSs could be employed as new drug delivery systems for therapeutic uses. They may represent a new class of ligands to be combined in a theranostic approach with fluorescent metals, such as Eu(III), to serve as imaging probe. The goal of this work was to investigate the feasibility of such coupling by time-resolved laser-induced fluorescence spectroscopy (TRLFS). Since these EPSs are polyelectrolytes their conformation could affect the complexation properties. Thus, viscosimetric measurements were performed as a function of their concentration as well as the background electrolyte concentration. Polysaccharides conformation exhibited a lower hydrodynamic volume for the highest ionic strengths. The resulting random-coiled conformation could affect the complexation with metal for high concentration but no change was evidenced when increasing europium concentration. Two sites of complexation of Eu(III) were evidenced by TRLFS in heparin, whereas only one site was evidenced in two modified EPSs produced from Alteromonas infernus.
Collapse
Affiliation(s)
- Sandrine Huclier-Markai
- GIP ARRONAX, 1 rue Aronnax, F-44817 Nantes Cedex 3, France. .,SUBATECH, 4 rue Alfred Kastler, BP 20722, 44307 Nantes Cedex 3, France
| | - Cyrille Alliot
- GIP ARRONAX, 1 rue Aronnax, F-44817 Nantes Cedex 3, France. .,INSERM U892- 8 quai Moncousu, F-44007 Nantes Cedex 1, France
| | - Mattia Mazza
- GIP ARRONAX, 1 rue Aronnax, F-44817 Nantes Cedex 3, France. .,SUBATECH, 4 rue Alfred Kastler, BP 20722, 44307 Nantes Cedex 3, France
| | - Pascal E Reiller
- Université Paris-Saclay, CEA, Service d'Etudes Analytiques et de Réactivité des Surfaces (SEARS), F-91191, Gif sur Yvette, France
| |
Collapse
|
5
|
Misra CS, Sounderajan S, Apte SK. Metal removal by metallothionein and an acid phosphatase PhoN, surface-displayed on the cells of the extremophile, Deinococcus radiodurans. JOURNAL OF HAZARDOUS MATERIALS 2021; 419:126477. [PMID: 34323731 DOI: 10.1016/j.jhazmat.2021.126477] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 05/31/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
The utility of surface layer proteins (Hpi and SlpA) of the radiation resistant bacterium, Deinococcus radiodurans, was investigated for surface display and bioremediation of cadmium and uranium. The smtA gene, from Synechococcus elongatus (encoding the metal binding metallothionein protein), was cloned and over-expressed in D. radiodurans, either as such or as a chimeric gene fused with hpi ORF (Hpi-SmtA), or fused to the nucleotide sequence encoding the SLH domain of the SlpA protein (SLH-SmtA). The expressed fusion proteins localized to the deinococcal cell surface, while the SmtA protein localized to the cytoplasm. Recombinant cells surface-displaying the SLH-SmtA or Hpi-SmtA fusion proteins respectively removed 1.5-3 times more cadmium than those expressing only cytosolic SmtA. The deinococcal Hpi protein layer per se also contributed to U binding, by conferring substantial negative charge to deinococcal cell surface. The ORF of an acid phosphatase, PhoN was fused with the hpi or SLH domain DNA sequence and purified. Isolated Hpi-PhoN and SLH-PhoN, immobilized on deinococcal peptidoglycan showed efficient uranium precipitation (446 and 160 mg U/g biomass used respectively). The study demonstrates effective exploitation of the deinococcal S layer protein components for (a) cell surface-based sequestration of cadmium, and (b) cell-free preparations for uranium remediation.
Collapse
Affiliation(s)
- Chitra Seetharam Misra
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400094, India.
| | - Suvarna Sounderajan
- Analytical Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400094, India
| | - Shree Kumar Apte
- School of Biosciences, UM-DAE-Centre for Excellence in Basic Sciences, Vidyanagari, Kalina, Mumbai 400098, India.
| |
Collapse
|
6
|
Hufton J, Harding J, Smith T, Romero-González ME. The importance of the bacterial cell wall in uranium(VI) biosorption. Phys Chem Chem Phys 2021; 23:1566-1576. [PMID: 33404558 DOI: 10.1039/d0cp04067c] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The bacterial cell envelope, in particular the cell wall, is considered the main controlling factor in the biosorption of aqueous uranium(vi) by microorganisms. However, the specific roles of the cell wall, associated biomolecules, and other components of the cell envelope are not well defined. Here we report findings on the biosorption of uranium by isolated cell envelope components and associated biomolecules, with P. putida 33015 and B. subtilis 168 investigated as representative strains for the differences in Gram-negative and Gram-positive cell envelope architecture, respectively. The cell wall and cell surface membrane were isolated from intact cells and characterised by X-ray Photoelectron Spectroscopy (XPS) and Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FT-IR) spectroscopy; revealing variations in the abundance of functional moieties and biomolecules associated with components of the cell envelope. Uranium biosorption was investigated as a function of cell envelope component and pH, comparing with intact cells. The isolated cell wall from both strains exhibited the greatest uranium biosorption capacity. Deprotonation of favourable functional groups on the biomass as the pH increased from 3 to 5.5 increased their uranium biosorption capacity by approximately 3 fold. The results from ATR-FT-IR indicated that uranium(vi) biosorption was mediated by phosphate and carboxyl groups associated with proteins and phosphorylated biopolymers of the cell envelope. This includes outer membrane phospholipids and LPS of Gram-negative bacteria and teichoic acids, surface proteins and peptidoglycan from Gram-positive bacteria. As a result, the biosorption process of uranium(vi) to microorganisms is controlled by surface interactions, resulting in higher accumulation of uranium in the cell envelope. This demonstrates the importance of bacterial cell wall as the key mediator of uranium biosorption with microorganisms.
Collapse
Affiliation(s)
- Joseph Hufton
- Department of Geography, The University of Sheffield, Sheffield, S10 2TN, UK.
| | - John Harding
- Department of Materials Science and Engineering, Sir Robert Hadfield Building, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK
| | - Thomas Smith
- Biomolecular Sciences Centre, Sheffield Hallam University, City Campus, Sheffield S1 1WB, UK
| | - Maria E Romero-González
- Department of Geography, The University of Sheffield, Sheffield, S10 2TN, UK. and School of Engineering and Materials Science (SEMS), Queen Mary University of London, Mile End Road, London E1 4NS, UK.
| |
Collapse
|
7
|
Kretzschmar J, Strobel A, Haubitz T, Drobot B, Steudtner R, Barkleit A, Brendler V, Stumpf T. Uranium(VI) Complexes of Glutathione Disulfide Forming in Aqueous Solution. Inorg Chem 2020; 59:4244-4254. [PMID: 32148028 DOI: 10.1021/acs.inorgchem.9b02921] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The interactions between glutathione disulfide, GSSG, the redox partner and dimer of the intracellular detoxification agent glutathione, GSH, and hexavalent uranium, U(VI), were extensively studied by solution NMR (in D2O), complemented by time-resolved laser-induced fluorescence and IR spectroscopies. As expected for the hard Lewis acid U(VI), coordination facilitates by the ligands' O-donor carboxyl groups. However, owing to the adjacent cationic α-amino group, the glutamyl-COO reveal monodentate binding, while the COO of the glycyl residues show bidentate coordination. The log K value for the reaction UO22+ + H3GSSG- → UO2(H3GSSG)+ (pH 3, 0.1 M NaClO4) was determined for the first time, being 4.81 ± 0.08; extrapolation to infinite dilution gave log K⊖ = 5.24 ± 0.08. U(VI) and GSSG form precipitates in the whole pD range studied (2-8), showing least solubility for 4 < pD < 6.5. Thus, particularly GSSG, hereby representing also other peptides and small proteins, affects the mobility of U(VI), strongly depending on the speciation of either component.
Collapse
Affiliation(s)
- Jerome Kretzschmar
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - Alexander Strobel
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - Toni Haubitz
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - Björn Drobot
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - Robin Steudtner
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - Astrid Barkleit
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - Vinzenz Brendler
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - Thorsten Stumpf
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden, Germany
| |
Collapse
|
8
|
Barkleit A, Hennig C, Ikeda-Ohno A. Interaction of Uranium(VI) with α-Amylase and Its Implication for Enzyme Activity. Chem Res Toxicol 2018; 31:1032-1041. [DOI: 10.1021/acs.chemrestox.8b00106] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Astrid Barkleit
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Christoph Hennig
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Atsushi Ikeda-Ohno
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany
| |
Collapse
|
9
|
Krawczyk-Bärsch E, Gerber U, Müller K, Moll H, Rossberg A, Steudtner R, Merroun ML. Multidisciplinary characterization of U(VI) sequestration by Acidovorax facilis for bioremediation purposes. JOURNAL OF HAZARDOUS MATERIALS 2018; 347:233-241. [PMID: 29324323 DOI: 10.1016/j.jhazmat.2017.12.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 12/04/2017] [Accepted: 12/10/2017] [Indexed: 06/07/2023]
Abstract
The contamination of the environment by U may affect plant life and consequently may have an impact on animal and human health. The present work describes U(VI) sequestration by Acidovorax facilis using a multidisciplinary approach combining wet chemistry, transmission electron microscopy, and spectroscopy methods (e.g. cryo-time resolved laser-induced fluorescence spectroscopy, extended X-ray absorption fine structure spectroscopy, and in-situ attenuated total reflection Fourier transform infrared spectroscopy). This bacterial strain is widely distributed in nature including U-contaminated sites. In kinetic batch experiments cells of A. facilis were contacted for 5 min to 48 h with 0.1 mM U(VI). The results show that the local coordination of U species associated with the cells depends upon time contact. U is bound mainly to phosphate groups of lipopolysaccharide (LPS) at the outer membrane within the first hour. And, that both, phosphoryl and carboxyl functionality groups of LPS and peptidoglycan of A. facilis cells may effectuate the removal of high U amounts from solution at 24-48 h of incubation. It is clearly demonstrated that A. facilis may play an important role in predicting the transport behaviour of U in the environment and that the results will contribute to the improvement of bioremediation methods of U-contaminated sites.
Collapse
Affiliation(s)
- E Krawczyk-Bärsch
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, D-01328 Dresden, Germany.
| | - U Gerber
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, D-01328 Dresden, Germany
| | - K Müller
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, D-01328 Dresden, Germany
| | - H Moll
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, D-01328 Dresden, Germany
| | - A Rossberg
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, D-01328 Dresden, Germany
| | - R Steudtner
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, D-01328 Dresden, Germany
| | - M L Merroun
- University of Granada, Department of Microbiology, Campus Fuentenueva, E-18071 Granada, Spain
| |
Collapse
|
10
|
Barkleit A, Heller A, Ikeda-Ohno A, Bernhard G. Interaction of europium and curium with alpha-amylase. Dalton Trans 2016; 45:8724-33. [DOI: 10.1039/c5dt04790k] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Batch sorption experiments, potentiometric and spectroscopic titration investigations revealed a fast and strong interaction of Eu(iii) and Cm(iii) with the digestive enzyme α-amylase.
Collapse
Affiliation(s)
- Astrid Barkleit
- Helmholtz-Zentrum Dresden-Rossendorf
- Institute of Resource Ecology
- 01314 Dresden
- Germany
| | - Anne Heller
- Helmholtz-Zentrum Dresden-Rossendorf
- Institute of Resource Ecology
- 01314 Dresden
- Germany
| | - Atsushi Ikeda-Ohno
- Helmholtz-Zentrum Dresden-Rossendorf
- Institute of Resource Ecology
- 01314 Dresden
- Germany
| | - Gert Bernhard
- Helmholtz-Zentrum Dresden-Rossendorf
- Institute of Resource Ecology
- 01314 Dresden
- Germany
| |
Collapse
|
11
|
Qian J, Zhang S, Zhou Y, Dong P, Hua D. Synthesis of surface ion-imprinted magnetic microspheres by locating polymerization for rapid and selective separation of uranium(vi). RSC Adv 2015. [DOI: 10.1039/c4ra10037a] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
New surface ion-imprinted magnetic microspheres are developed by locating polymerization for uranium(vi) adsorption with ultrafast kinetics and high selectivity.
Collapse
Affiliation(s)
- Jun Qian
- School for Radiological and Interdisciplinary Sciences (RAD-X)
- School of Radiation Medicine and Protection
- Medical College of Soochow University
- Suzhou 215123
- China
| | - Shuang Zhang
- School for Radiological and Interdisciplinary Sciences (RAD-X)
- School of Radiation Medicine and Protection
- Medical College of Soochow University
- Suzhou 215123
- China
| | - Yuan Zhou
- School for Radiological and Interdisciplinary Sciences (RAD-X)
- School of Radiation Medicine and Protection
- Medical College of Soochow University
- Suzhou 215123
- China
| | - Ping Dong
- School for Radiological and Interdisciplinary Sciences (RAD-X)
- School of Radiation Medicine and Protection
- Medical College of Soochow University
- Suzhou 215123
- China
| | - Daoben Hua
- School for Radiological and Interdisciplinary Sciences (RAD-X)
- School of Radiation Medicine and Protection
- Medical College of Soochow University
- Suzhou 215123
- China
| |
Collapse
|
12
|
Reitz T, Rossberg A, Barkleit A, Steudtner R, Selenska-Pobell S, Merroun ML. Spectroscopic study on uranyl carboxylate complexes formed at the surface layer of Sulfolobus acidocaldarius. Dalton Trans 2015; 44:2684-92. [DOI: 10.1039/c4dt02555e] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The complexation of U(vi) at the proteinaceous surface layer (S-layer) of the archaeal strain Sulfolobus acidocaldarius was investigated at the molecular scale using TRLFS and EXAFS spectroscopy.
Collapse
Affiliation(s)
- Thomas Reitz
- Helmholtz-Center Dresden-Rossendorf
- Institute of Resource Ecology
- 01328 Dresden
- Germany
- Helmholtz-Center for Environmental Research
| | - Andre Rossberg
- Helmholtz-Center Dresden-Rossendorf
- Institute of Resource Ecology
- 01328 Dresden
- Germany
| | - Astrid Barkleit
- Helmholtz-Center Dresden-Rossendorf
- Institute of Resource Ecology
- 01328 Dresden
- Germany
| | - Robin Steudtner
- Helmholtz-Center Dresden-Rossendorf
- Institute of Resource Ecology
- 01328 Dresden
- Germany
| | - Sonja Selenska-Pobell
- Helmholtz-Center Dresden-Rossendorf
- Institute of Resource Ecology
- 01328 Dresden
- Germany
| | | |
Collapse
|
13
|
Thomas KJ, Rice CV. Revised model of calcium and magnesium binding to the bacterial cell wall. Biometals 2014; 27:1361-70. [PMID: 25315444 DOI: 10.1007/s10534-014-9797-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Accepted: 09/28/2014] [Indexed: 11/26/2022]
Abstract
Metals bind to the bacterial cell wall, yet the binding mechanisms and affinity constants are not fully understood. The cell wall of gram positive bacteria is characterized by a thick layer of peptidoglycan and anionic teichoic acids anchored in the cytoplasmic membrane as lipoteichoic acid or covalently bound to the cell wall as wall teichoic acid. The polyphosphate groups of teichoic acid provide one-half of the metal binding sites for calcium and magnesium, which contradicts previous reports that calcium binding is 100 % dependent on teichoic acid. The remaining binding sites are formed with the carboxyl units of peptidoglycan. In this work we report equilibrium association constants and total metal binding capacities for the interaction of calcium and magnesium ions with the bacterial cell wall. Metal binding is much stronger than previously reported. Curvature of Scatchard plots from the binding data and the resulting two regions of binding affinity suggest the presence of negative cooperative binding, which means that the binding affinity decreases as more ions become bound to the sample. For Ca(2+), Region I has a KA = (1.0 ± 0.2) × 10(6) M(-1) and Region II has a KA = (0.075 ± 0.058) × 10(6) M(-1). For Mg(2+), KA1 = (1.5 ± 0.1) × 10(6) and KA2 = (0.17 ± 0.10) × 10(6). A binding capacity (η) is reported for both regions. However, since binding is still occurring in Region II, the total binding capacity is denoted by η2, which are 0.70 ± 0.04 and 0.67 ± 0.03 µmol/mg for Ca(2+) and Mg(2+) respectively. These data contradict the current paradigm of only a single metal affinity value that is constant over a range of concentrations. We also find that measurement of equilibrium binding constants is highly sample dependent. This suggests a role for diffusion of metals through heterogeneous cell wall fragments. As a result, we are able to reconcile many contradictory theories that describe binding affinity and the binding mode of divalent metal cations.
Collapse
Affiliation(s)
- Kieth J Thomas
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | | |
Collapse
|
14
|
Decrease of U(VI) immobilization capability of the facultative anaerobic strain Paenibacillus sp. JG-TB8 under anoxic conditions due to strongly reduced phosphatase activity. PLoS One 2014; 9:e102447. [PMID: 25157416 PMCID: PMC4144796 DOI: 10.1371/journal.pone.0102447] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 06/19/2014] [Indexed: 11/28/2022] Open
Abstract
Interactions of a facultative anaerobic bacterial isolate named Paenibacillus sp. JG-TB8 with U(VI) were studied under oxic and anoxic conditions in order to assess the influence of the oxygen-dependent cell metabolism on microbial uranium mobilization and immobilization. We demonstrated that aerobically and anaerobically grown cells of Paenibacillus sp. JG-TB8 accumulate uranium from aqueous solutions under acidic conditions (pH 2 to 6), under oxic and anoxic conditions. A combination of spectroscopic and microscopic methods revealed that the speciation of U(VI) associated with the cells of the strain depend on the pH as well as on the aeration conditions. At pH 2 and pH 3, uranium was exclusively bound by organic phosphate groups provided by cellular components, independently on the aeration conditions. At higher pH values, a part (pH 4.5) or the total amount (pH 6) of the dissolved uranium was precipitated under oxic conditions in a meta-autunite-like uranyl phosphate mineral phase without supplying an additional organic phosphate substrate. In contrast to that, under anoxic conditions no mineral formation was observed at pH 4.5 and pH 6, which was clearly assigned to decreased orthophosphate release by the cells. This in turn was caused by a suppression of the indigenous phosphatase activity of the strain. The results demonstrate that changes in the metabolism of facultative anaerobic microorganisms caused by the presence or absence of oxygen can decisively influence U(VI) biomineralization.
Collapse
|
15
|
Morcillo F, González-Muñoz MT, Reitz T, Romero-González ME, Arias JM, Merroun ML. Biosorption and Biomineralization of U(VI) by the marine bacterium Idiomarina loihiensis MAH1: effect of background electrolyte and pH. PLoS One 2014; 9:e91305. [PMID: 24618567 PMCID: PMC3949747 DOI: 10.1371/journal.pone.0091305] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 02/12/2014] [Indexed: 11/18/2022] Open
Abstract
The main goal of this study is to compare the effects of pH, uranium concentration, and background electrolyte (seawater and NaClO4 solution) on the speciation of uranium(VI) associated with the marine bacterium Idiomarina loihiensis MAH1. This was done at the molecular level using a multidisciplinary approach combining X-ray Absorption Spectroscopy (XAS), Time-Resolved Laser-Induced Fluorescence Spectroscopy (TRLFS), and High Resolution Transmission Electron Microscopy (HRTEM). We showed that the U(VI)/bacterium interaction mechanism is highly dependent upon pH but also the nature of the used background electrolyte played a role. At neutral conditions and a U concentration ranging from 5·10−4 to 10−5 M (environmentally relevant concentrations), XAS analysis revealed that uranyl phosphate mineral phases, structurally resembling meta-autunite [Ca(UO2)2(PO4)2 2–6H2O] are precipitated at the cell surfaces of the strain MAH1. The formation of this mineral phase is independent of the background solution but U(VI) luminescence lifetime analyses demonstrated that the U(VI) speciation in seawater samples is more intricate, i.e., different complexes were formed under natural conditions. At acidic conditions, pH 2, 3 and 4.3 ([U] = 5·10−4 M, background electrolyte = 0.1 M NaClO4), the removal of U from solution was due to biosorption to Extracellular Polysaccharides (EPS) and cell wall components as evident from TEM analysis. The LIII-edge XAS and TRLFS studies showed that the biosorption process observed is dependent of pH. The bacterial cell forms a complex with U through organic phosphate groups at pH 2 and via phosphate and carboxyl groups at pH 3 and 4.3, respectively. The differences in the complexes formed between uranium and bacteria on seawater compared to NaClO4 solution demonstrates that the actinide/microbe interactions are influenced by the three studied factors, i.e., the pH, the uranium concentration and the chemical composition of the solution.
Collapse
Affiliation(s)
- Fernando Morcillo
- Departamento de Microbiología, Universidad de Granada, Granada, Spain
| | | | - Thomas Reitz
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | | | - José M. Arias
- Departamento de Microbiología, Universidad de Granada, Granada, Spain
| | - Mohamed L. Merroun
- Departamento de Microbiología, Universidad de Granada, Granada, Spain
- * E-mail:
| |
Collapse
|
16
|
Cheng Y, Xu X, Yan S, Pan X, Chen Z, Lin Z. Hydrothermal growth of large-size UO2 nanoparticles mediated by biomass and environmental implications. RSC Adv 2014. [DOI: 10.1039/c4ra10428e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We reveal the hydrothermal conversion rule for amorphous U(vi) to large-size UO2.
Collapse
Affiliation(s)
- Yangjian Cheng
- College of Environment and Resources
- Fuzhou University
- Fuzhou, China
- State Key Laboratory of Structural Chemistry
- Fujian Institute of Research on the Structure of Matter
| | - Xinya Xu
- College of Environment and Resources
- Fuzhou University
- Fuzhou, China
| | - Shungao Yan
- State Key Laboratory of Structural Chemistry
- Fujian Institute of Research on the Structure of Matter
- Chinese Academy of Sciences
- Fuzhou, China
| | - Xiaohong Pan
- State Key Laboratory of Structural Chemistry
- Fujian Institute of Research on the Structure of Matter
- Chinese Academy of Sciences
- Fuzhou, China
| | - Zhi Chen
- State Key Laboratory of Structural Chemistry
- Fujian Institute of Research on the Structure of Matter
- Chinese Academy of Sciences
- Fuzhou, China
| | - Zhang Lin
- State Key Laboratory of Structural Chemistry
- Fujian Institute of Research on the Structure of Matter
- Chinese Academy of Sciences
- Fuzhou, China
| |
Collapse
|
17
|
Lütke L, Moll H, Bachvarova V, Selenska-Pobell S, Bernhard G. The U(vi) speciation influenced by a novel Paenibacillus isolate from Mont Terri Opalinus clay. Dalton Trans 2013; 42:6979-88. [DOI: 10.1039/c3dt33032j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
18
|
Abstract
The in situ stimulation of Fe(III) oxide reduction in the subsurface stimulates the growth of Geobacter spp. and the precipitation of U(VI) from groundwater. As with Fe(III) oxide reduction, the reduction of uranium by Geobacter spp. requires the expression of their conductive pili. The pili bind the soluble uranium and catalyse its extracellular reductive precipitation along the pili filaments as a mononuclear U(IV) complexed by carbon-containing ligands. Although most of the uranium is immobilized by the pili, some uranium deposits are also observed in discreet regions of the outer membrane, consistent with the participation of redox-active foci, presumably c-type cytochromes, in the extracellular reduction of uranium. It is unlikely that cytochromes released from the outer membrane could associate with the pili and contribute to the catalysis, because scanning tunnelling microscopy spectroscopy did not reveal any haem-specific electronic features in the pili, but, rather, showed topographic and electronic features intrinsic to the pilus shaft. Pili not only enhance the rate and extent of uranium reduction per cell, but also prevent the uranium from traversing the outer membrane and mineralizing the cell envelope. As a result, pili expression preserves the essential respiratory activities of the cell envelope and the cell's viability. Hence the results support a model in which the conductive pili function as the primary mechanism for the reduction of uranium and cellular protection in Geobacter spp.
Collapse
|
19
|
Mukherjee A, Wheaton GH, Blum PH, Kelly RM. Uranium extremophily is an adaptive, rather than intrinsic, feature for extremely thermoacidophilic Metallosphaera species. Proc Natl Acad Sci U S A 2012; 109:16702-7. [PMID: 23010932 PMCID: PMC3478614 DOI: 10.1073/pnas.1210904109] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Thermoacidophilic archaea are found in heavy metal-rich environments, and, in some cases, these microorganisms are causative agents of metal mobilization through cellular processes related to their bioenergetics. Given the nature of their habitats, these microorganisms must deal with the potentially toxic effect of heavy metals. Here, we show that two thermoacidophilic Metallosphaera species with nearly identical (99.99%) genomes differed significantly in their sensitivity and reactivity to uranium (U). Metallosphaera prunae, isolated from a smoldering heap on a uranium mine in Thüringen, Germany, could be viewed as a "spontaneous mutant" of Metallosphaera sedula, an isolate from Pisciarelli Solfatara near Naples. Metallosphaera prunae tolerated triuranium octaoxide (U(3)O(8)) and soluble uranium [U(VI)] to a much greater extent than M. sedula. Within 15 min following exposure to "U(VI) shock," M. sedula, and not M. prunae, exhibited transcriptomic features associated with severe stress response. Furthermore, within 15 min post-U(VI) shock, M. prunae, and not M. sedula, showed evidence of substantial degradation of cellular RNA, suggesting that transcriptional and translational processes were aborted as a dynamic mechanism for resisting U toxicity; by 60 min post-U(VI) shock, RNA integrity in M. prunae recovered, and known modes for heavy metal resistance were activated. In addition, M. sedula rapidly oxidized solid U(3)O(8) to soluble U(VI) for bioenergetic purposes, a chemolithoautotrophic feature not previously reported. M. prunae, however, did not solubilize solid U(3)O(8) to any significant extent, thereby not exacerbating U(VI) toxicity. These results point to uranium extremophily as an adaptive, rather than intrinsic, feature for Metallosphaera species, driven by environmental factors.
Collapse
Affiliation(s)
- Arpan Mukherjee
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695-7905; and
| | - Garrett H. Wheaton
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695-7905; and
| | - Paul H. Blum
- Beadle Center for Genetics, University of Nebraska-Lincoln, Lincoln, NE 68588-0666
| | - Robert M. Kelly
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695-7905; and
| |
Collapse
|
20
|
French S, Puddephatt D, Habash M, Glasauer S. The dynamic nature of bacterial surfaces: Implications for metal–membrane interaction. Crit Rev Microbiol 2012; 39:196-217. [DOI: 10.3109/1040841x.2012.702098] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
21
|
Lütke L, Moll H, Bernhard G. Insights into the uranium(vi) speciation with Pseudomonas fluorescens on a molecular level. Dalton Trans 2012; 41:13370-8. [DOI: 10.1039/c2dt31080e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
22
|
Extracellular reduction of uranium via Geobacter conductive pili as a protective cellular mechanism. Proc Natl Acad Sci U S A 2011; 108:15248-52. [PMID: 21896750 DOI: 10.1073/pnas.1108616108] [Citation(s) in RCA: 149] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The in situ stimulation of Fe(III) oxide reduction by Geobacter bacteria leads to the concomitant precipitation of hexavalent uranium [U(VI)] from groundwater. Despite its promise for the bioremediation of uranium contaminants, the biological mechanism behind this reaction remains elusive. Because Fe(III) oxide reduction requires the expression of Geobacter's conductive pili, we evaluated their contribution to uranium reduction in Geobacter sulfurreducens grown under pili-inducing or noninducing conditions. A pilin-deficient mutant and a genetically complemented strain with reduced outer membrane c-cytochrome content were used as controls. Pili expression significantly enhanced the rate and extent of uranium immobilization per cell and prevented periplasmic mineralization. As a result, pili expression also preserved the vital respiratory activities of the cell envelope and the cell's viability. Uranium preferentially precipitated along the pili and, to a lesser extent, on outer membrane redox-active foci. In contrast, the pilus-defective strains had different degrees of periplasmic mineralization matching well with their outer membrane c-cytochrome content. X-ray absorption spectroscopy analyses demonstrated the extracellular reduction of U(VI) by the pili to mononuclear tetravalent uranium U(IV) complexed by carbon-containing ligands, consistent with a biological reduction. In contrast, the U(IV) in the pilin-deficient mutant cells also required an additional phosphorous ligand, in agreement with the predominantly periplasmic mineralization of uranium observed in this strain. These findings demonstrate a previously unrecognized role for Geobacter conductive pili in the extracellular reduction of uranium, and highlight its essential function as a catalytic and protective cellular mechanism that is of interest for the bioremediation of uranium-contaminated groundwater.
Collapse
|
23
|
Reitz T, Merroun ML, Rossberg A, Steudtner R, Selenska-Pobell S. Bioaccumulation of U(VI) by Sulfolobus acidocaldarius under moderate acidic conditions. RADIOCHIM ACTA 2011. [DOI: 10.1524/ract.2011.1848] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
U(VI) accumulation by the acidothermophilic archaeon Sulfolobus acidocaldarius at a moderate acidic pH of 4.5 was investigated. This pH value is relevant for some heavy metal and uranium polluted environments where populations of S. acidocaldarius were found to persist. We demonstrate that U(VI) is rapidly complexed by the archaeal cells. A combination of X-ray absorption spectroscopy and time-resolved laser-induced fluorescence spectroscopy revealed that at pH 4.5 organic phosphate and carboxylic groups are involved in the U(VI) complexation. These results are in contrast to those published for most bacteria which at this pH precipitate U(VI) mainly in inorganic uranyl phosphate phases. As demonstrated by TEM only a limited part of the added U(VI) was biomineralized extracellularly in the case of the studied archaeon. Most of the U(VI) accumulates were localized in a form of intracellular deposits which were associated with the inner side of the cytoplasma membrane. Observed differences in U(VI) bioaccumulation between the studied archaeon and bacteria can be explained by the significant differences in their cell wall structures as well as by their different physiological characteristics.
Collapse
Affiliation(s)
| | - M. L. Merroun
- Forschungszentrum Dresden-Rossendorf, Institute of Radiochemistry, Dresden, Deutschland
| | - A. Rossberg
- Forschungszentrum Rossendorf, Institute of Radiochemistry, Dresden, Deutschland
| | - Robin Steudtner
- Forschungszentrum Dresden-Rossendorf, Institute of Radiochemistry, Dresden, Deutschland
| | - Sonja Selenska-Pobell
- Forschungszentrum Dresden-Rossendorf, Institute of Radiochemistry, Dresden, Deutschland
| |
Collapse
|
24
|
Yuan LY, Liu YL, Shi WQ, Lv YL, Lan JH, Zhao YL, Chai ZF. High performance of phosphonate-functionalized mesoporous silica for U(vi) sorption from aqueous solution. Dalton Trans 2011; 40:7446-53. [DOI: 10.1039/c1dt10085h] [Citation(s) in RCA: 139] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|