PhD thesis

Molecular investigation of the binding, the uptake mechanism and the transport of radionuclides in fungal biomass.

Anne Wollenberg

Anne Wollenberg
Prof. Dr. Thorsten Stumpf, Dr. Johannes Raff, Dr. Alix Günther (HZDR)
07/2016 – 06/2019

Radionuclides are widely used in industry, medicine and research. By their use, disposal, but also by accidental release radionuclides may reach the environment. There, their mobility and their behaviour are influenced by interactions with abiotic and biotic matter. As fungi are one of the most common microorganisms in nature, they have to be taken into consideration in particular. They play an important role for preservation of the soil structure and protect plants and symbiotic organisms from intoxication. Furthermore, they interact with radionuclides in different ways leading to an immobilization and thus a reduced toxicity and a reduced migration through the soil.

The aim of this study is the investigation of the binding, the uptake and the transport through the hypha of different radionuclides by the two fungi Leucoagaricus naucinus and Schizophyllum commune. For this, we investigate the influence of different starting condition, e.g. pH value or initial metal concentration, on the binding behavior of both fungi. Furthermore, the molecular interactions should be investigated with time-resolved laser-induced fluorescence spectroscopy (TRLFS), infrared and raman spectroscopy and other spectroscopic methods to identify the bound radionuclide species and involved bioligands. To study the localization of radionuclides in the fungal cell and the transport mechanism through the mycelium different microscopic methods, e.g. transmission electron microscopy in combination with dispersive X-ray spectroscopy (TEM-EDX) and confocal laser scanning microscopy will be used.

This Ph.D. thesis is integrated in the BMBF project BioVeStRa (Investigation of the potential of biological processes for the precautionary radiation protection in case of radionuclide contamination).