TY - JOUR
T1 - Mineralization and Preservation of an extremotolerant Bacterium Isolated from an Early Mars Analog Environment
AU - Gaboyer, F.
AU - Le Milbeau, C.
AU - Bohmeier, M.
AU - Schwendner, P.
AU - Vannier, P.
AU - Beblo-Vranesevic, K.
AU - Rabbow, E.
AU - Foucher, F.
AU - Gautret, P.
AU - Guégan, R.
AU - Richard, A.
AU - Sauldubois, A.
AU - Richmann, P.
AU - Perras, A. K.
AU - Moissl-Eichinger, C.
AU - Cockell, C. S.
AU - Rettberg, P.
AU - Marteinsson,
AU - Monaghan, E.
AU - Ehrenfreund, P.
AU - Garcia-Descalzo, L.
AU - Gomez, F.
AU - Malki, M.
AU - Amils, R.
AU - Cabezas, P.
AU - Walter, N.
AU - Westall, F.
N1 - Funding Information:
MASE is supported by European Community’s Seventh Framework Programme (FP7/2007-2013) under Grant Agreement n° 607297. We also thank Rachel Boscardin for Rock-Eval analysis and Mohammed Boussafir for discussions of Rock-Eval results, both from ISTO.
Publisher Copyright:
© 2017 The Author(s).
PY - 2017/12/1
Y1 - 2017/12/1
N2 - The artificial mineralization of a polyresistant bacterial strain isolated from an acidic, oligotrophic lake was carried out to better understand microbial (i) early mineralization and (ii) potential for further fossilisation. Mineralization was conducted in mineral matrixes commonly found on Mars and Early-Earth, silica and gypsum, for 6 months. Samples were analyzed using microbiological (survival rates), morphological (electron microscopy), biochemical (GC-MS, Microarray immunoassay, Rock-Eval) and spectroscopic (EDX, FTIR, RAMAN spectroscopy) methods. We also investigated the impact of physiological status on mineralization and long-term fossilisation by exposing cells or not to Mars-related stresses (desiccation and radiation). Bacterial populations remained viable after 6 months although the kinetics of mineralization and cell-mineral interactions depended on the nature of minerals. Detection of biosignatures strongly depended on analytical methods, successful with FTIR and EDX but not with RAMAN and immunoassays. Neither influence of stress exposure, nor qualitative and quantitative changes of detected molecules were observed as a function of mineralization time and matrix. Rock-Eval analysis suggests that potential for preservation on geological times may be possible only with moderate diagenetic and metamorphic conditions. The implications of our results for microfossil preservation in the geological record of Earth as well as on Mars are discussed.
AB - The artificial mineralization of a polyresistant bacterial strain isolated from an acidic, oligotrophic lake was carried out to better understand microbial (i) early mineralization and (ii) potential for further fossilisation. Mineralization was conducted in mineral matrixes commonly found on Mars and Early-Earth, silica and gypsum, for 6 months. Samples were analyzed using microbiological (survival rates), morphological (electron microscopy), biochemical (GC-MS, Microarray immunoassay, Rock-Eval) and spectroscopic (EDX, FTIR, RAMAN spectroscopy) methods. We also investigated the impact of physiological status on mineralization and long-term fossilisation by exposing cells or not to Mars-related stresses (desiccation and radiation). Bacterial populations remained viable after 6 months although the kinetics of mineralization and cell-mineral interactions depended on the nature of minerals. Detection of biosignatures strongly depended on analytical methods, successful with FTIR and EDX but not with RAMAN and immunoassays. Neither influence of stress exposure, nor qualitative and quantitative changes of detected molecules were observed as a function of mineralization time and matrix. Rock-Eval analysis suggests that potential for preservation on geological times may be possible only with moderate diagenetic and metamorphic conditions. The implications of our results for microfossil preservation in the geological record of Earth as well as on Mars are discussed.
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U2 - 10.1038/s41598-017-08929-4
DO - 10.1038/s41598-017-08929-4
M3 - Article
C2 - 28821776
AN - SCOPUS:85027894958
SN - 2045-2322
VL - 7
JO - Scientific Reports
JF - Scientific Reports
IS - 1
M1 - 8775
ER -