Adaptive strategies of microorganisms to extreme environmental conditions: Molecular mechanisms of desiccation and UV radiation resistance in the bacterium Deinococcus radiodurans

• Applicant: Dr. Petra Rettberg
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: from 2003 to 2007
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5417601

Deinococcus radiodurans is a gram positive bacterium whose ability to survive extremely high DNA damages induced by ionizing radiation, including heavy ions, or desiccation is still not completely understood. Because of its radiation and desiccation resistance, this extremophile is a prime candidate to possibly survive environmental conditions as they occur on Mars and during an interplanetary space travel. Little work has been done so far on the effects of UV radiation, especially polychromatic UV in the UVB and UVA range, and vacuum exposure, which is known to induce DNA damages similar to radiation. Therefore, in the work proposed here, we intend to further investigate the radiation resistance and the repair mechanisms of Deinococcus radiodurans, especially the effect of polychromatic UV radiation and vacuum and simulated Mars radiation and desiccation/pressure conditions, in wild type and radiation sensitive mutants. Induced photoproducts will be detected, identified and quantified by HPLC-Tandem-mass-spectrometry and the use of specific DNA photoproduct antibodies. In addition, it will be investigated whether Deinococcus radiodurans survives the simulated environmental conditions of an interplanetary space travel, i.e. on a space craft, and on Mars. The results will contribute to the understanding of the mechanisms of the extraordinary radiation resistance of Deinococcus radiodurans and its ability to repair and survive a highly damaged genome lethal to other organisms, and be of great interest to questions concerning planetary protection, space craft disinfecting measures and the search for life on other earth like planets in general.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1115: Mars and the Terrestrial Planets
• Participating Person: Dr. Elke Rabbow