Examinando por Autor "Bohmeier, M."

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Acceso Abierto
Impact of Simulated Martian Conditions on (Facultatively) Anaerobic Bacterial Strains from Different Mars Analogue Sites.
(Multidisciplinary Digital Publishing Institute (MDPI), 2020-01-15) Beblo Vranesevic, K.; Bohmeier, M.; Schleumer, S.; Rabbow, Elke; Perras, A. K.; Moissl-Eichinger, Christine; Schwendner, P.; Cockell, Charles S.; Vannier, P.; Marteinsson, V. T.; Monaghan, E. P.; Riedo, A.; Ehrenfreund, P.; García Descalzo, L.; Gómez, Felipe; Malki, M.; Amils Pibernat, R.; Gaboyer, F.; Hickman-Lewis, K.; Westall, Frances; Cabezas, Patricia; Walter, N.; Rettberg, P.; Rettberg, P. [0000-0003-4439-2395]; García Descalzo, L. [0000-0002-0083-6786]; Cabezas, P. [0000-0002-6336-4093]; Marteinsson, V. [0000-0001-8340-821X]; Gómez, F. [0000-0001-9977-7060]
Five bacterial (facultatively) anaerobic strains, namely Buttiauxella sp. MASE-IM-9, Clostridium sp. MASE-IM-4, Halanaerobium sp. MASE-BB-1, Trichococcus sp. MASE-IM-5, and Yersinia intermedia MASE-LG-1 isolated from different extreme natural environments were subjected to Mars relevant environmental stress factors in the laboratory under controlled conditions. These stress factors encompassed low water activity, oxidizing compounds, and ionizing radiation. Stress tests were performed under permanently anoxic conditions. The survival rate after addition of sodium perchlorate (Na-perchlorate) was found to be species-specific. The inter-comparison of the five microorganisms revealed that Clostridium sp. MASE-IM-4 was the most sensitive strain (D-10-value (15 min, NaClO4) = 0.6 M). The most tolerant microorganism was Trichococcus sp. MASE-IM-5 with a calculated D-10-value (15 min, NaClO4) of 1.9 M. Cultivation in the presence of Na-perchlorate in Martian relevant concentrations up to 1 wt% led to the observation of chains of cells in all strains. Exposure to Na-perchlorate led to a lowering of the survival rate after desiccation. Consecutive exposure to desiccating conditions and ionizing radiation led to additive effects. Moreover, in a desiccated state, an enhanced radiation tolerance could be observed for the strains Clostridium sp. MASE-IM-4 and Trichococcus sp. MASE-IM-5. These data show that anaerobic micro-organisms from Mars analogue environments can resist a variety of Martian-simulated stresses either individually or in combination. However, responses were species-specific and some Mars-simulated extremes killed certain organisms. Thus, although Martian stresses would be expected to act differentially on microorganisms, none of the expected extremes tested here and found on Mars prevent the growth of anaerobic microorganisms.
Acceso Abierto
Limits of Life and the Habitability of Mars: The ESA Space Experiment BIOMEX on the ISS
(Mary Ann Liebert, 2019-02-11) De Vera, Jean Pierre; Alawi, Mashal; Backhaus, Theresa; Baqué, Mickael; Billi, Daniela; Böttger, Ute; Berger, T.; Bohmeier, M.; Cockell, Charles S.; Demets, René; de la Torre Noetzel, Maria Rosa; Edwards, Howell; Elsaesser, Andreas; Fagliarone, Claudia; Fiedler, Annelie; Foing, Bernard; Foucher, Frédéric; Fritz, Jörg; Hanke, Franziska; Herzog, Thomas; Horneck, Gerda; Hübers, Heinz-Wilhelm; Huwe, Björn; Joshi, Jasmin; Kozyrovska, Natalia; Kruchten, Martha; Lasch, Peter; Lee, Natuschka; Leuko, Stefan; Leya, Thomas; Lorek, Andreas; Martínez Frías, Jesús; Meessen, Joachim; Moritz, Sophie; Moeller, Ralf; Olsson-Francis, Karen; Onofri, Silvano; Ott, Sieglinde; Pacelli, Claudia; Podolich, Olga; Rabbow, Elke; Reitz, Günther; Rettberg, Petra; Reva, Oleg; Rothschild, Lynn; García Sancho, Leo; Schulze Makuch, D.; Selbmann, Laura; Serrano, Paloma; Szewzyk, Ulrich; Verseux, Cyprien; Wadsworth, Jennifer; Wagner, Dirk; Westall, Frances; Wolter, David; Zucconi, Laura; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Agenzia Spaziale Italiana (ASI); National Academy of Sciences of Ukraine (NASU); German Centre for Air and Space Travel; Helmholtz Association
BIOMEX (BIOlogy and Mars EXperiment) is an ESA/Roscosmos space exposure experiment housed within the exposure facility EXPOSE-R2 outside the Zvezda module on the International Space Station (ISS). The design of the multiuser facility supports—among others—the BIOMEX investigations into the stability and level of degradation of space-exposed biosignatures such as pigments, secondary metabolites, and cell surfaces in contact with a terrestrial and Mars analog mineral environment. In parallel, analysis on the viability of the investigated organisms has provided relevant data for evaluation of the habitability of Mars, for the limits of life, and for the likelihood of an interplanetary transfer of life (theory of lithopanspermia). In this project, lichens, archaea, bacteria, cyanobacteria, snow/permafrost algae, meristematic black fungi, and bryophytes from alpine and polar habitats were embedded, grown, and cultured on a mixture of martian and lunar regolith analogs or other terrestrial minerals. The organisms and regolith analogs and terrestrial mineral mixtures were then exposed to space and to simulated Mars-like conditions by way of the EXPOSE-R2 facility. In this special issue, we present the first set of data obtained in reference to our investigation into the habitability of Mars and limits of life. This project was initiated and implemented by the BIOMEX group, an international and interdisciplinary consortium of 30 institutes in 12 countries on 3 continents. Preflight tests for sample selection, results from ground-based simulation experiments, and the space experiments themselves are presented and include a complete overview of the scientific processes required for this space experiment and postflight analysis. The presented BIOMEX concept could be scaled up to future exposure experiments on the Moon and will serve as a pretest in low Earth orbit.