The basis of the manifold metabolic processes induced in microorganisms after exposure to various kinds of stress is investigated at the molecular level.
The response of Bacillus subtilis endospores after irradiation with UV and ionizing radiation as well as with heavy ions during and after germination is analyzed with the DNA microarray technology. Special emphasis is laid on the examination of different DNA repair pathways. DNA photodamage is characterized qualitatively and quantitativley in cooperation with CEA (Grenoble, F). The potential photoprotective role of different pigments in Bacillus subtilis endospores as microbial adaptation to high levels of ambient UV radiation is under investigation.
The molecular mechanisms of desiccation and UV radiation resistance are investigated in the polyextremophile model organism Deinococcus radiodurans. This project DradUV (DFG project RE 1574/1 and -2) is part of the DFG focus ‘Mars and terrestrial planets’. The aim is to reach a better understanding of the remarkable DNA repair efficiency of this bacterium, especially with respect to UV induced damage and to test wether Deinococcus radiodurans could even survive under the environmental conditions of mars. The survivability of endolithic microorganisms (lichens, cyanobacteria) and bacterial spores during a simulated impact and ejection of Martian meteorites is analysed in the project IMPACT (DFG project HO 1508/3-1 and -2, DFG focus ‘Mars and terrestrial planets’) with national and international partners. The biological effects as well as the shock metamorphisms of the ejected microorganism-bearing rock fragments of hypervelocity impacts are investigated up to 50 GPa which corresponds to the peak shock pressure estimates for the presently studied Martian meteorites.