Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

If radionuclides are released in the environment their mobility and behavior is influenced by interactions with abiotic and biotic matter. As fungi are ubiquitous in nature they have to be taken into consideration in particular. For example, fungi can bind radionuclides in different ways, with the result that the radionuclides are immobilized and preventing further migration through the soil. The aim of this study was to investigate the binding of uranium and europium, the latter as surrogate for trivalent actinides, by fungi Schizophyllum commune and Leucoagaricus naucinus.
First batch experiments showed the binding of U(VI) and Eu(III) by fungi depends on the initial conditions. Both fungi showed increasing sorption capacities with higher initial metal concentrations and lower initial biomass. In contrast, the fungi showed different metal binding behavior in dependence on pH. Scanning transmission electron microscopy in combination with high angle annular dark-field analysis (HAADF-STEM) revealed location of U(VI) on the surface and inside of cells of Schizophyllum commune.
Furthermore the U(VI)-binding of the fungi was investigate with time-resolved laser-induced fluorescence spectroscopy (TRLFS) depending on metal concentration. The results showed the speciation of U(VI) is changed in the initial solution during binding process. In addition, it was demonstrated that mainly phosphate groups are responsible for the binding on the surface of the biomass.