Contact

Dr. Johannes Raff

Head Biogeochemistry
j.raffAthzdr.de
Phone: +49 351 260 2951

Social Media

  Twitter-Logo

Department of Biogeochemistry


Research in the Biogeochemistry department focuses on understanding the interaction of long-lived radionuclides with biosystems. We are interested in the various levels from biomolecules to individual organisms and complex biocoenoses. On the one hand, the aim is to understand the influence of biological systems on the behavior of radionuclides in the environment (release, mobility and bioavailability). On the other hand, we investigate the effects of radionuclides on the metabolism of cells and the whole organism (uptake, accumulation, chemo- and radiotoxicity) and the resulting dangers for us humans.

Using state-of-the-art molecular biological, spectroscopic and microscopic methods, we work in the fields of repository research to improve the long-term safety of a repository for high-level radioactive waste and radioecology to protect humans and the environment from the dangers of naturally and artificially released radionuclides.

In addition to basic research, our aim is to use the knowledge gained to develop innovative remediation methods and improve models to describe the behavior of radionuclides in the environment.

Interested in working with us?

To support our work, we are always looking for students and interns from the fields of biology, chemistry and environmental sciences who either want to write their thesis with us or simply gain practical experience. Are you interested? Then please get in touch to clarify any questions you may have.


Current research topics

Working fields of the departement of biogeochemistry at the Institute of Resource Ecology (EN) ©Copyright: Dr. Matschiavelli, Nicole
  • Determination of the microbial diversity in water and soil environments contaminated with heavy metals and radionuclides as well as in different host rocks for potential radioactive waste disposals
  • Microbe-radionuclide-interactions with reference strains and isolates
  • Interaction of eukaryotic cells with radionuclides and lanthanides in particular with plants, fungi, sponges and algae
  • Investigation of the interaction of selected bioligands and model compounds with f-elements
  • Characterization of microbial processes affecting the conditions in deep geological repositories for radioactive waste (e.g. transformation of bentonite as barrier material)
  • Calculation and determination of the metal speciation relevant to the environment
  • Verification and validation of transport models
  • Characterization of particles in the environment relevant to the transport of radionuclides
  • Investigation of the transport processes of radionuclides by particles (including microbes) in natural water

Latest Publication

Biostimulation of Indigenous Microbes for Uranium Bioremediation in Former U Mine Water: Multidisciplinary approach assessment

Newman Portela, A.; Krawczyk-Bärsch, E.; Lopez Fernandez, M.; Bok, F.; Kassahun, A.; Drobot, B.; Steudtner, R.; Stumpf, T.; Raff, J.; Merroun, M. L.

Characterizing the physicochemistry and microbial diversity of U mine water is a key prerequisite for understanding the biogeochemical processes occurring in these water mass and for the design of an efficient bioremediation strategy. This study has collected and analysed in reference date measurements water samples from two former U-mines (Schlema-Alberoda and Pöhla, Wismut GmbH) in East Germany. The samples from both mines are pH-circumneutral (7.3 and 6.6) and show reducing conditions (EH: +139 and –91 mV). Interestingly, the U and sulphate concentrations of Schlema-Alberoda mine water (U: 1 mg/L; SO4>/sub> 2−: 335 mg/L) are 2 and 3 order of magnitude higher than those of the Pöhla samples (U: 0.01 mg/L; SO4 2−: 0.5 mg/L), respectively. U, SO4 2− and Fe seem to shape the differential microbial diversity of the water from both mines. Microbial diversity analysis revealed the distribution of bacteria with U(VI)-reducing capacity and the ability to maintain the stability of reduced U-species (e.g., Desulfurivibrio, Gallionella and Sulfuricurvum). In addition, water from the mines harbour wood-degrading fungal communities (e.g., composed of Cadophora and Acremonium) providing potential electron donors which promote the growth of U-reducing bacteria. For the design of a bioremediation strategy, we conducted a preliminary U-bioreduction experiment to screen for suitable electron donors (glycerol, vanillic acid and gluconic acid). We also observed that high levels of soluble U (initially present as Ca2UO2(CO3)3>/sub>(aq) and UO2(CO3) 3>sup>4−>/sup>), Fe and SO4 2− were removed by 98, 95 and 53%, respectively from the mine water by using glycerol as electron donor. The remaining U concentrations after bioreduction meet regulatory standards for beneficial reuse of U mine water. As a whole, the results reveal the chemical factors influencing the microbial community in U mine water and may contribute to the design of bioremediation strategies based on the biostimulation of U-reducing bacteria for low U concentrations in contaminated water.

Keywords: bioremediation; bioreduction; mine water; uranium; bacterial; fungal


Projects


Team

Foto: Gruppenbild der Abteilung Biogeochemie des Instituts für Ressourcenökologie ©Copyright: Dr. Johannes Raff

Head

NameBld./Office+49 351 260Email
Dr. Johannes Raff801/P3142951
j.raffAthzdr.de

Employees

NameBld./Office+49 351 260Email
Rahel Bertheau801/P3543138
Julia Marie Dauwe801/P3062860
j.dauweAthzdr.de
Dr. Björn Drobot801/P3172895
b.drobotAthzdr.de
Katrin Flemming801/P3092958
k.flemmingAthzdr.de
Dr. Alix Günther801/P2562433
2522
a.guentherAthzdr.de
Max Klotzsche801/P3063241
m.klotzscheAthzdr.de
Dr. Evelyn Krawczyk-Bärsch801/P2522076
e.krawczyk-baerschAthzdr.de
Raul Eduardo Linares Jimenez801/P2052438
r.linares-jimenezAthzdr.de
Dr. Henry Moll801/P2562433
2549
h.mollAthzdr.de
Antonio Newman Portela801/P2542251
a.newman-portelaAthzdr.de
Dr. Susanne Sachs801/P2082436
s.sachsAthzdr.de
Jana Seibt801/P2193194
2510
j.seibtAthzdr.de
Dr. Robin Steudtner801/P3172895
r.steudtnerAthzdr.de
Lukas Waurick801/P3063241
l.waurickAthzdr.de

MICRONUC

NameBld./Office+49 351 260Email
Dr. Andrea Cherkouk801/P3562989
a.cherkoukAthzdr.de
Sindy Kluge801/P2193194
s.klugeAthzdr.de
Dr. Nicole Matschiavelli801/P3182759
n.matschiavelliAthzdr.de
Dr. Ting-Shyang Wei801/P3182759
t.weiAthzdr.de