Reversible pH-dependent curium(III) biosorption by the bentonite yeast isolate Rhodotorula mucilaginosa BII-R8

JOURNAL OF HAZARDOUS MATERIALS

卷:370

Article; Proceedings Paper

Lopez-Fernandez, Margarita^1,2  Moll, Henry²  Merroun, Mohamed L.¹ 

[1] Univ Granada, Fac Sci, Dept Microbiol, Ave Fuentenueva S-N, E-18071 Granada, Spain

[2] Helmholtz Zentrum Dresden Rossendorf, Inst Resource Ecol, Bautzner Landstr 400, D-01328 Dresden, Germany

关键词: Curium;    Europium;    Biosorption;    Yeast Rhodotorula mucilaginosa;    Time-Resolved Laser Induced Fluorescence Spectroscopy (TRLFS);   

DOI  :  10.1016/j.jhazmat.2018.06.054

来源: Elsevier

【 摘 要 】

This work describes the molecular characterization of the interaction mechanism of a bentonite yeast isolate, Rhodotorula mucilaginosa BII-R8, with curium(III) as representative of trivalent actinides and europium(III) used as inactive analogue of Cm(III). A multidisciplinary approach combining spectroscopy, microscopy and flow cytometry was applied. Time-Resolved Laser Induced Fluorescence Spectroscopy (TRLFS) analyses demonstrated that the biosorption of Cm(III) is a reversible and pH-dependent process for R. mucilaginosa BII-R8 cells. Two Cm (III)-R. mucilaginosa BII-R8 species were identified having emission maxima at 599.6 and 601.5 nm. They were assigned to Cm(III) species bound to phosphoryl and carboxyl sites from the yeast cell, respectively. Phosphate groups were involved in the sorption of this actinide, as demonstrated by the Eu(III)-phosphate accumulates at the cell membrane shown by microscopy. In addition, cell viability and metabolic potential were assessed to determine the negative effect of Eu(III) in the yeast cells. The results obtained in this work showed that the interaction of Cm(III) with the yeast R. mucilaginosa BII-R8 cells at circumneutral and alkaline pH values will make this radionuclide more mobile to reach the biosphere. Therefore, geochemical conditions in the bentonite engineering barrier need to be carefully adjusted for the safe deep geological disposal of radioactive wastes.

【 授权许可】

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