Tolerance limits of methanogenic life in terrestrial permafrost

• Main Authors: Morozova, Daria, Wagner, Dirk
• Format: Conference Object
• Language: unknown
• Published: 2005
• Subjects: Ice; permafrost
• Online Access: https://epic.awi.de/id/eprint/13390/; https://hdl.handle.net/10013/epic.23774

TOLERANCE LIMITS OF METHANOGENIC LIFE IN TERRESTRIAL PERMAFROSTD. Morozova and D. WagnerAlfred Wegener Institute for Polar and Marine Research, Telegrafenberg A 43, 14473 Potsdam, [e-mail]: Prokaryotic microfossils, found in early Archaean rocks, implies that the earliest life forms on Earth probably date from between 3.5 3.8 Ga ago [1, 2], when living conditions on Mars were similar to those on early Earth. Therefore it is legitimate to assume that life on Mars emerged as well as on Earth. Accepting that first life on both planets was determined by complex microbial communities, the Martian life must have adapted to drasti-cally changing environmental conditions or be-come again extinct. One possibility for survival of Martian primitive life might be subsurface lithoautotrophic ecosystems. Comparable envi-ronments exist in permafrost regions on Earth [3, 4].The current ESA (European Space Agency) mission Mars Express determined the existence of water as ground ice on Mars, which is a fun-damental requirement for life. Furthermore, Mars Express demonstrated for the first time the presence of CH4 in the Martian atmosphere, which due to the lifetime of CH4 could be only originated from active volcanism or biological sources [5]. This finding may have important implications for the possibility that microbial life could exist on Mars.Methanogenic archaea colonising terrestrial permafrost, are highly specialized organisms from the view point of metabolism. The capa-bility of these organisms to lithoautotrophic growth under strictly anaerobic conditions [6], tolerance to low temperatures and survival un-der extreme conditions of permafrost for sev-eral millions of years [7, 8] make methanogens one of the most suitable keystone organism for the investigation of possible Martian life [9].Main Results of the 1st period of applica-tion: Within the scope of the project we study the tolerances of methanogens under unfavour-able life conditions of terrestrial or extraterres-trial permafrost (Mars ...