The mutual relationship of the evolution of planets and life is the subject of the research alliance 'Planetary Evolution and Life'. Under the administration of the German Aerospace Center (DLR) and funded by the Helmholtz Association of German Research Centres (HGF) the alliance connects different fields of research to investigate the possibility of life on other celestial bodies. The Environmental Microbiology Group takes part in the alliance within the topic 'Physics and Biology of Interfacial Water'.

Ironprecipitating bacteria serve as model organisms for life under martian conditions. Feasable forms of metabolism and simple food chains with other microorganisms are examined. Phototrophic iron oxidation could play a role in ironrich martian soils as well as a possible coexistence of methanotrophic iron oxidizers with methanogenic archaea.

The formation of biofilms and the deposition of iron hydroxides by these bacteria possibly enable them to endure dry conditions and UV light. The influence of interactions with minerals and other microorganisms on the capability to tolerate dry stress is studied in desiccation experiments. Thermogravimetric measurements are carried out to gain information about water sorption properties of biofilms.