The experimental conditions can be summarized as follows: each one of the three stocks was grown in a culture medium enriched with NaCl, MgSO4 and Na3PO4 at 2%, 5% and 10% w/v concentration. The acidity of the culture medium was set at pH values of 2.0, 5.5 and 9.0 with a phosphate buffer. The Europa’s ocean surface scenario

was simulated using a hermetically isolated 100-mL flask where 50 mL of the 10% TSB medium was inoculated with a combination of T806-1 and T806-3 strains and enriched with 5% NaCl and 10% MgSO4 at a pH value of 5.5. Tests were performed introducing 50 mbar of 5%, 10% and 20% v/v oxygen content balanced with argon. Three different MDV3100 nmr stocks were isolated and characterized. Two of them, T806-1 and T806-3 were perfectly able to grow in the presence of up to 10% of NaCl and PP2 MgSO4 and at an acidity value of 5.5. These conditions have specific relevance to the Europan ocean. Their growth showed the capability of these bacteria to adapt to high contents of salts. The halotolerant bacteria have also

demonstrated their capability to resist short exposures to low temperatures (below the water freezing point), after which they continue viable. The implications of all these results in the frame of a salty Europan ocean will be presented and discussed. We thank Concepción Chino for help with sequencing and analysis of 16S rRNA. This work was supported through a CONACyT 52291 grant. Dassarma, Org 27569 Shiladitya, (2006). Extreme Halophiles are

models for Astrobiology. Microbe, 1(3). Marion, G., Fritsen, C., Eicken, H., and Payne, M. (2003). The search for life on Europe: Limiting environmental factors, potential habitats, and Earth analogues. Astrobiology, 3(4):785–811. Oren, A. (1999). Bioenergetic aspects of halophilism. Microbiol. Mol. Biol. Rev. 63: 334–348. Rothschild, L. J. and Mancinelli, R. L. (2001). Life in Extreme Environments. Nature, 409: 1092–1101. E-mail: ramirez_​sandra@ciq.​uaem.​mx Extraterrestrial Nucleobases in the Murchison Meteorite Zita Martins1,2, Oliver Botta3,4,5, Marilyn L. Fogel6, Mark A. Sephton2, Daniel P. Glavin3, Jonathan S. Watson7, Jason P. Dworkin3, Alan W. Schwartz8, Pascale Ehrenfreund1,3 1Astrobiology Laboratory, Leiden Institute of Chemistry, Leiden, The Netherlands; 2Department of Earth Science and Engineering, selleck products Imperial College London, UK; 3NASA Goddard Space Flight Center, Code 699, Greenbelt, USA; 4Goddard Earth Sciences and Technology Center, Univ.