Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.jhazmat.2011.09.049
Title (Primary) Bio-precipitation of uranium by two bacterial isolates recovered from extreme environments as estimated by potentiometric titration, TEM and X-ray absorption spectroscopic analyses
Author Merroun, M.L.; Nedelkova, M.; Ojeda, J.; Reitz, T. ORCID logo ; López Fernández, M.; Arias, J.M.; Romero-González, M.; Selenska-Pobell, S.
Source Titel Journal of Hazardous Materials
Year 2011
Department BOOEK
Volume 197
Page From 1
Page To 10
Language englisch
Keywords Uranium biomineralization; Potentiometric titration; XAS; TEM/EDX; Acid phosphatase
Abstract

This work describes the mechanisms of uranium biomineralization at acidic conditions by Bacillus sphaericus JG-7B and Sphingomonas sp. S15-S1 both recovered from extreme environments. The U–bacterial interaction experiments were performed at low pH values (2.0–4.5) where the uranium aqueous speciation is dominated by highly mobile uranyl ions. X-ray absorption spectroscopy (XAS) showed that the cells of the studied strains precipitated uranium at pH 3.0 and 4.5 as a uranium phosphate mineral phase belonging to the meta-autunite group. Transmission electron microscopic (TEM) analyses showed strain-specific localization of the uranium precipitates. In the case of B. sphaericus JG-7B, the U(VI) precipitate was bound to the cell wall. Whereas for Sphingomonas sp. S15-S1, the U(VI) precipitates were observed both on the cell surface and intracellularly. The observed U(VI) biomineralization was associated with the activity of indigenous acid phosphatase detected at these pH values in the absence of an organic phosphate substrate. The biomineralization of uranium was not observed at pH 2.0, and U(VI) formed complexes with organophosphate ligands from the cells. This study increases the number of bacterial strains that have been demonstrated to precipitate uranium phosphates at acidic conditions via the activity of acid phosphatase.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=12248
Merroun, M.L., Nedelkova, M., Ojeda, J., Reitz, T., López Fernández, M., Arias, J.M., Romero-González, M., Selenska-Pobell, S. (2011):
Bio-precipitation of uranium by two bacterial isolates recovered from extreme environments as estimated by potentiometric titration, TEM and X-ray absorption spectroscopic analyses
J. Hazard. Mater. 197 , 1 - 10 10.1016/j.jhazmat.2011.09.049