Scholarship in Germany.

Job Description: Iron is one of the major redox elements in the Earth crust and can be reduced and oxidized by bacteria. During these redox reactions, Fe minerals are dissolved, transformed or formed. Magnetite (Fe3O4) is a magnetic Fe(II)-Fe(III)-mineral and can be formed both by microbial Fe(II) oxidation and Fe(III) reduction. Since microbial activities (including microbial iron mineral formation) are strongly influenced by the presence of contaminants, it was suggested that magnetic properties can be used to delineate anthropogenic contamination accumulating in soil and sediments. Magnetic proxy screening may therefore serve as a fast and cost-effective, qualitative or semi-quantitative, tool for initial site characterization and for repeated measurements to observe the evolution of pollution (monitoring). However, the mechanisms and conditions controlling the reductive and oxidative formation and transformation of magnetic minerals (mainly magnetite) are not known in detail but need to !
be understood in order to apply magnetic measurements for assessment of environmental contamination.

The proposed interdisciplinary research project will be done in close collaboration with the research group for Geophysics at the University of Tübingen and aims at identifying the conditions under which magnetite is formed and transformed using field studies and laboratory experiments. Geochemical analyses (e.g. by wet-chemistry and chromatography), mineralogical studies (e.g. XRD, Mössbauer spectroscopy, magnetic measurements) and microbiological approaches (cultivation dependent and independent techniques including molecular ecological analyses based on DNA/RNA techniques) will be used to study sediments collected at a former military base. The redox conditions, iron mineralogy, and magnetic properties will be determined at the field site. Aerobic and anaerobic Fe(II)-oxidizing as well as Fe(III)-reducing bacteria will be localized, quantified, isolated and identified and iron mineral (in particular magnetite) formation by the isolated strains will be determined.

We offer a PhD position in an interdisciplinary, international, young and dynamic team of microbiologists, geochemists and environmental geoscientists. This position provides an opportunity to bring in the candidate’s own creativity and self-responsibility. Not only will you learn and apply various lab techniques, but you will also practice and improve your ability to discuss and present problems and results in a friendly atmosphere.

Application Deadline 31August2010

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