Unlocking the bentonite microbial diversity and its implications in selenium bioreduction and biotransformation: Advances in deep geological repositories
Povedano-Priego C, Jroundi F, Solari PL, Guerra-Tschuschke I, Abad-Ortega MdM, Link A, Vilchez-Vargas R, Merroun ML (2023)
Publication Type: Journal article
Publication year: 2023
Journal
Book Volume: 445
Article Number: 130557
DOI: 10.1016/j.jhazmat.2022.130557
Abstract
Selenium, 79Se, is one of the most critical radionuclides in radioactive waste disposed in future deep geological repositories (DGRs). Here, we investigate the impact of bentonite microbial communities on the allotropic transformation of Se(IV) bioreduction products under DGR relevant conditions. In addition, Se amendment-dependent shifts in the bentonite microbial populations are assessed. Microcosms of water-saturated bentonites were spiked with a bacterial consortium, treated with selenite and incubated anaerobically for six months. A combination of X-Ray Absorption Spectroscopy, Electron Microscopy, and Raman Spectroscopy was used to track the allotropic changes of the Se bioreduction products. Interestingly, the color of bentonite shifted from orange to black in the selenite-treated microcosms. In the orange layers, amorphous or monoclinic Se(0) were identified, whilst black precipitates consisted of stable trigonal Se(0) form. Illumina DNA sequencing indicated the distribution of strains with Se(IV) reducing and Se(0) allotropic biotransformation potential, like Pseudomonas, Stenotrophomonas, Desulfosporosinus, and unclassified-Desulfuromonadaceae. The archaea Methanosarcina decreased its abundance in the presence of Se(IV), probably caused by this oxyanion toxicity. These findings provide an understanding of the bentonite microbial strategies involved in the immobilization of Se(IV) by reduction processes, and prove their implication in the allotropic biotransformation from amorphous to trigonal Se(0) under DGR relevant conditions.
Involved external institutions
Universidad de Granada
Spain (ES)
Synchrotron SOLEIL
France (FR)
Otto-von-Guericke-Universität Magdeburg
Germany (DE)
Spain (ES)
Synchrotron SOLEIL
France (FR)
Otto-von-Guericke-Universität Magdeburg
Germany (DE)
How to cite
APA:
Povedano-Priego, C., Jroundi, F., Solari, P.L., Guerra-Tschuschke, I., Abad-Ortega, M.d.M., Link, A.,... Merroun, M.L. (2023). Unlocking the bentonite microbial diversity and its implications in selenium bioreduction and biotransformation: Advances in deep geological repositories. Journal of Hazardous Materials, 445. https://doi.org/10.1016/j.jhazmat.2022.130557
MLA:
Povedano-Priego, Cristina, et al. "Unlocking the bentonite microbial diversity and its implications in selenium bioreduction and biotransformation: Advances in deep geological repositories." Journal of Hazardous Materials 445 (2023).
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