Molecular interaction of fungi with uranium

The radioactive and toxic element uranium is mined in large quantities, for example for industrial or research purposes, and subsequently stored as waste. This increases the risk of anthropogenic release into the environment, where it can enter the groundwater and thus the food chain through leaching and migration. However, the surrounding microbial community can influence the migration behavior of uranium. An important part of this community are fungi that can interact with uranium through various processes such as sorption, accumulation or mineralization. These processes can restrict the mobility of uranium and prevent migration into the waterways and subsequently the food chain.
The aim of this study is to investigate the potential of fungi for precautionary radiation protection methods or even bioremediation procedures for contaminated soils. In assessing the suitability of fungi, the first task is to investigate the molecular interactions with uranium in detail. For this purpose, binding experiments with the two fungi Schizophyllum commune and Leucoagaricus naucinus are conducted in various media to determine the influence of the environment on the uranium binding behavior of fungi. Time-resolved laser-induced fluorescence spectroscopy was used to investigate the speciation of fungal bound uranium. Furthermore, the location of bound uranium was determined using transmission electron microscopy with energy dispersive X-ray spectroscopy. In addition, microcosm experiments were carried out with soil to investigate the interactions of fungi with uranium under natural conditions.
The results so far show that the uranium binding of the fungi is very different but largely independent of the surrounding medium. This suggests that the interactions are mainly determined by the biochemistry of fungi.