Distribution of different uranium oxidation states in thin sections of uranium-incubated bacterial cells

The microbial transformation of U(VI) to relatively insoluble U(IV) is a subject of extensive investigation but lacks a comprehensive understanding. This proposal aims to characterize the spatial distribution of different oxidation states of uranium following bioreduction by Desulfosporosinus hippei DSM 8344T, an anaerobic sulfate-reducing microorganism, and Desulfitobacterium sp. G1-2, an iron-reducing bacterium isolated from a bentonite sample. Thin-sectioned samples of uranium-incubated cells will be utilized for the first time for these investigations using High-Energy Resolution Fluorescence Detection (HERFD) at U M4 edge. Obtaining information about the various oxidation states and their distribution within or outside of the cells is crucial for gaining a more detailed understanding of the reduction process. This is of particular importance for the understanding of the bioreduction of U.