Long-lived radionuclides in biosystems
The exploitation of natural resources of metals and radiometals entails the perturbation of ecological systems in the context of mining or waste disposal. A key concern of the society is the minimization of detrimental effects by either of these activities. To accomplish this goal, the underlying molecular processes need to be understood to assess the biological risks and to prevent health hazards.
The Research Topic "Long-lived Radionuclides in Biosystems" aims at understanding the physical, chemical and biological processes that lead to the transfer of metals and radionuclides from the geo- to the biosphere. Correspondingly, research activities under this topic are highly interdisciplinary. For example, the speciation of actinides in soil and pore water and at interfaces with the biosystems is studied as well as the fate of ingested metals within an organism.
Currently, phenomenological parameters such as transfer factor and uptake are used to evaluate the spread of contaminants in the food chain, without considering chemical interactions. To fill this obvious gap, we divide this transfer into sub-processes that are investigated in vitro and in vivo. The biochemical basis of the extracellular interaction and the cellular uptake / export of long-lived radionuclides by soil organisms, plants and animal cells and their effect on the metabolism are central activities and concern the development of low-dose risk assessment strategies in suitable model organisms.
Current research addresses the diversity and activity of microbial populations in host rock formations and barrier material being in discussion for a possible deep-geological repository and other radionuclide contaminated sites. We explore the biochemical basis of their interaction with long-lived radionuclides leading to sorption, accumulation, mineralization, biotransformation and metabolic interference. These factors can re-affect geochemical processes such as migration of uranium (and other actinides) and should be considered in the selection of repository host rocks. A variety of spectroscopic, microscopic, calorimetric and molecular biological methods is used to understand the relation between the chemical state of radionuclides, their location on a µm scale within organisms and their effect on metabolism.
- "Plutonium interaction studies with the Mont Terri Opalinus Clay isolate Sporomusa sp. MT-2.99: changes in the plutonium speciation by solvent extractions."
Moll, H.; Cherkouk, A.; Bok, F.; Bernhard, G.Environ. Sci. Pollut. Res. 2011, 2017, Online-First.
- "Multistage bioassociation of uranium onto an extremely halophilicarchaeon revealed by a unique combination of spectroscopic and microscopic techniques"
M. Bader, K. Müller, H. Foerstendorf, B. Drobot, M. Schmidt, N. Musat, J. S. Swanson, T. Reed, T. Stumpf, A. Cherkouk, Journal of Hazardous Materials 2017, 327(15), 225-232.
- "Interaction of Europium and Curium with Alpha-Amylase"
A. Barkleit, A. Heller, A. Ikeda-Ohno, G. Bernhard, Dalton Trans., 2016, 45 8724–8733
- "Combined use of flow cytometry and microscopy to study the interactions between the gram-negative betaproteobacterium Acidovorax facilis and uranium(VI)"
Gerber, U.; Zirnstein, I.; Krawczyk-Bärsch, E.; Lünsdorf, H.; Arnold, T.; Merroun, M. L.,Journal of Hazardous Materials, 2016, 317, 127-134