Water retention of selected microorganisms and Martian soil simulants under close to Martian environmental conditions

Based on the latest knowledge about microorganisms resistant towards extreme conditions on Earth and results of new complex models on the development of the Martian atmosphere we quantitatively examined the water-bearing properties of selected extremophiles and simulated Martian regolith components and their interaction with water vapor under close to Martian environmental conditions. Three different species of microorganisms have been chosen and prepared for our study: Deinococcus geothermalis, Leptothrix sp. OT_B_406, and Xanthoria elegans. Further, two mineral mixtures representing the early and the late Martian surface as well as montmorillonite as a single component of phyllosilicatic minerals, typical for the Noachian period on Mars, were selected. The thermal mass loss of the minerals and bacteria-samples was measured by thermoanalysis. The hydration and dehydration properties were determined under close to Martian environmental conditions by sorption isotherm measurements using a McBain-Bakr quartz spring balance. It was possible to determine the total water content of the materials as well as the reversibly bound water fraction as function of the atmospheres humidity by means of these methods. Our results are important for the evaluation of future space mission outcomes including astrobiological aspects and can support the modeling of the atmosphere/surface interaction by showing the influence on the water inventory of the upper most layer of the Martian surface.

[1]  T. Encrenaz,et al.  Mars Surface Diversity as Revealed by the OMEGA/Mars Express Observations , 2005, Science.

[2]  E. Hauber,et al.  Outgassing History and Escape of the Martian Atmosphere and Water Inventory , 2015, 1506.06569.

[3]  J. Wiegel,et al.  Extremophiles: from abyssal to terrestrial ecosystems and possibly beyond , 2011, Naturwissenschaften.

[4]  S. Pokrzywnicki,et al.  The Thermal Decomposition of Manganese Carbonate Thermogravimetry and Exoemission of Electrons , 1999 .

[5]  Jean-Pierre Bibring,et al.  Sulfates in Martian Layered Terrains: The OMEGA/Mars Express View , 2005, Science.

[6]  J. Vera.  Lichens as survivors in space and on Mars , 2012 .

[7]  Andreas Lorek,et al.  Survival potential and photosynthetic activity of lichens under Mars-like conditions: a laboratory study. , 2010, Astrobiology.

[8]  R. E. Arvidson,et al.  Phyllosilicates on Mars and implications for early martian climate , 2005, Nature.

[9]  G. Horneck,et al.  Survival of lichens and bacteria exposed to outer space conditions – Results of the Lithopanspermia experiments , 2010 .

[10]  E. G. Mulder,et al.  Investigations on theSphaerotilus-Leptothrix group , 1963, Antonie van Leeuwenhoek.

[11]  J. Carey,et al.  Controlled-Humidity XRD Analyses: Application to the Study of Smectite Expansion/Contraction , 1995 .

[12]  William V. Boynton,et al.  Global distribution of near-surface hydrogen on Mars , 2004 .

[13]  Jean Rouquerol,et al.  Reporting Physisorption Data for Gas/Solid Systems , 2008 .

[14]  Heinz-Wilhelm Hübers,et al.  Optimizing the detection of carotene in cyanobacteria in a martian regolith analogue with a Raman spectrometer for the ExoMars mission , 2012 .

[15]  D. Möhlmann,et al.  Hygroscopic salts and the potential for life on Mars. , 2010, Astrobiology.

[16]  M. Salkinoja-Salonen,et al.  Firm but Slippery Attachment of Deinococcus geothermalis , 2002, Journal of bacteriology.

[17]  P. Bertsch,et al.  Distinguishing Between Surface and Bulk Dehydration-Dehydroxylation Reactions in Synthetic Goethites by High-Resolution Thermogravimetric Analysis , 1999 .

[18]  Mikhail S. Gelfand,et al.  Deinococcus geothermalis: The Pool of Extreme Radiation Resistance Genes Shrinks , 2007, PloS one.

[19]  D. Möhlmann,et al.  Investigation of the water sorption properties of Mars-relevant micro- and mesoporous minerals , 2006 .

[20]  M. Dubinin.  Theory of the physical adsorption of gases and vapors and adsorption properties of adsorbents of various natures and porous structures , 1960 .