The influence of shock pressure, pre-shock temperature, and host rock composition on the survival rate of endolithic microorganisms during impact ejection from Mars

Petrographic and biological analysis of shock recovery experiments confirms the possible life transport due to an impact from Mars to Earth

Insight of lichens as ideal models for astrobiological studies analyzed by Raman spectroscopy

Exposure experiments of different species to space conditions are essential because real space conditions with different radiation sources like ionizing radiation, UV-radiation, X-rays, gamma-ray from even galactic radiation, vacuum and space weathering by micro-dust cannot simultaneously be simulated in parallel even in our best simulation chambers on Earth. We need results from experiments under real space conditions to enable the development of appropriate predictions about the stability of organisms and their constituent organic parts. The extremophile lichen Circinaria gyrosa is one of the selected species within the BIOMEX (Biology and Mars Experiment) experiment and in this work we compare the previous Raman results obtained in this lichen [1] with the corresponding Raman results on the lichen Xanthoparmelia hueana. Both species have been exposed to space and simulated Mars-like conditions in planetary chambers and we have studied and identified possible degradation process in different layers and biomarkers. The analysis by Raman spectroscopy of simulated Space and Mars exposed samples confirm alterations and damages of the photobiont part of the lichen and changes related to the molecular structure of whewellite. The conclusions of this work will be important to understand what are the effects to consider when biological systems are exposed to space or Mars-like conditions and to expand our knowledge of how life survives in most extreme conditions that is a prerequisite in future planetary exploration projects.Acknowledgment Support for this work was provided by the Spanish Ministry of Economy, Industry and Competitiveness (MINECO), by the project BIOindicadores en MARTE y Espacio (BIOMARSS) (PID2019-109448RB-I00) and by INTA. References [1] M.R. Lopez Ramirez, L.G Sancho, J. P. de Vera, M. Baqué, U. Böttcher, E. Rabbow, J. Martínez-Frías, R. de la Torre Noetzel. Spectrochimica Acta, Part A. 261 (2021) 120046.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

The BIOMEX experiment on-board the International Space Station: limits of life and detection of biomarkers after exposure to space- and to Mars-like conditions

To explore the limits of terrestrial life in space, we have to understand the effects of the space environment on unprotected biological and chemical material, and on the degradation of organic molecules or biomarkers. The exposure platform EXPOSE-R2 on the ISS offer a suitable facility for the exposure of samples of the astrobiological model lichen Circinaria gyrosa, included in the BIOMEX experiment (Biology and Mars Experiment, ESA). During 18 months (2014-2016), the lichens lived in a latent state at space and at simulated Mars-like conditions, to study Mars’ habitability and resistance to space conditions. After the return of the samples in June 2016, initial analysis showed rapid recovery of photosystem II (PSII) activity in the samples exposed exclusively to space vacuum and to Mars-like atmosphere. In contrast, the samples directly exposed to solar UV radiation showed a slow and a lower recovery, in reference to their observed original activity. This tendency was corroborated with the complementary morphological/ultrastructural and biomolecular analyses. Complementary, the biogeochemical variations have been examined with Raman spectroscopy to assess the possible degradation of cell surfaces and pigments which were in contact with terrestrial rocks, and Martian analogue regolith. Identification of the biomarker whewellite (calcium oxalate) and other organic compounds and mineral products of the biological activity of Circinaria gyrosa were detected by Raman Laser. These findings contribute to answer questions on the habitability of Mars, the likelihood of the Lithopanspermia Hypothesis, the capability to detect biomolecules exposed to an extraterrestrial environment by life-detection instruments and will be of relevance for planetary protection issues

Panspermia, Past and Present: Astrophysical and Biophysical Conditions for the Dissemination of Life in Space

Astronomically, there are viable mechanisms for distributing organic material throughout the Milky Way. Biologically, the destructive effects of ultraviolet light and cosmic rays means that the majority of organisms arrive broken and dead on a new world. The likelihood of conventional forms of panspermia must therefore be considered low. However, the information content of dam-aged biological molecules might serve to seed new life (necropanspermia).Comment: Accepted for publication in Space Science Review

Resistance of Antarctic black fungi and cryptoendolithic communities to simulated space and Martian conditions

Dried colonies of the Antarctic rock-inhabiting meristematic fungi Cryomyces antarcticus CCFEE 515, CCFEE 534 and C. minteri CCFEE 5187, as well as fragments of rocks colonized by the Antarctic cryptoendolithic community, were exposed to a set of ground-based experiment verification tests (EVTs) at the German Aerospace Center (DLR, Köln, Germany). These were carried out to test the tolerance of these organisms in view of their possible exposure to space conditions outside of the International Space Station (ISS). Tests included single or combined simulated space and Martian conditions. Responses were analysed both by cultural and microscopic methods. Thereby, colony formation capacities were measured and the cellular viability was assessed using live/dead dyes FUN 1 and SYTOX Green. The results clearly suggest a general good resistance of all the samples investigated. C. minteri CCFEE 5187, C. antarcticus CCFEE 515 and colonized rocks were selected as suitable candidates to withstand space flight and long-term permanence in space on the ISS in the framework of the LIchens and Fungi Experiments (LIFE programme, European Space Agency)

The BIOMEX Experiment on-board the International Space Station: Biomolecular- and Bio-geochemical changes of lichens exposed to space- and to Mars-like conditions

Exploration of the solar system is a priority research area of the AstRoMap European Astrobiology Roadmap (Horneck et al., 2015) [1], focused on various research topics, one of them is “Life and Habitability” and an other one is “Biomarkers for easy the detection of life”. Therefore “space platforms and laboratories” are necessary, such as EXPOSE, to gain more knowledment of space- and extraterrestrial habitats, eventually for human interplanetary exploration (Space, Moon, Mars, Encedalus, Titan, Europa). At the exposure platform EXPOSE-R2 on ISS (2014-2016), samples of the astrobiological model system Circinaria gyrosa gyrosa [3,4,5,6], belonging to the BIOMEX experiment [2], (Biology and Mars Experiment, ESA), were exposed during 18 months to space and to a Mars simulated environment, to study Mars habitability and resistance to space conditions. The data obtained by the investigation on biomarkers after being exposed to Mars-like conditions will support the analysis of data obtained during future instrumental detection operations in future space missions on Mars (i.e. ExoMars). After the return of the samples in June 2016, the first preliminary analysis showed a quick and complete recovery of metabolic activity of the control samples exposed to space vacuum and Mars-like atmosphere. In contrast, the samples directly exposed to extraterrestrial UV solar radiation showed slow recovery, in reference to their observed original activity. Here we expose the last results that show the biomolecular changes of the DNA analized by PCR and complementary sequencing techniques, in correlation with the previous results supporting changes in metabolic activity, and changes in viability (Electron- and fluorescence microscopy techniques), as well as in morphology/ultrastructure due to space vacuum and Mars atmosphere. Additionaly, the biogeochemical variations have been examined with spectroscopic analyses (Raman) to look for possible degradation of cell surfaces and pigments which were in contact with terrestrial rocks, and Martian analogue regolith. Moreover, differences were observed between samples irradiated with extraterrestrial UV solar radiation and samples positioned below defined as dark-control samples. These experiments will contribute to answer questions on the habitability of Mars, on the likelihood of the Lithopanspermia Hypothesis and will be of relevance for planetary protection issues

MICROORGANISMS FROM MARS ANALOGUE ENVIRONMENTS IN EARTH - COULD THEY SURVIVE ON MARS?

Assessing the habitability of Mars and detecting life, if it was ever there, depends on knowledge of whether the combined environmental stresses experienced on Mars are compatible with life and whether a record of that life could ever be detected. Many combinations of Mars relevant stress factors, such as high radiation dose rates and high UV uences combined with high salt concentrations, and low water activity, have not been investigated. In particular, the response of anaerobic organisms to Mars-like stress factors and combinations thereof are not known. In the EC project MASE (Mars Analogues for Space Exploration) we address these limitations by characterising different Mars analogue environments on Earth, isolating microorganisms from these sites and exposing them to Mars relevant stress factors alone and in combination. We want to find out, if these bacteria respond in an additive or synergistic way and if they would be able to survive on Mars. So far, eight only distantly related microorganisms are under detailed investigation, e.g Yersinia sp., Halanaerobium sp., Acidiphilum sp. Desulfovibrio sp.. Unexpectedly, a Yersinia strain turned out to be quite resistant, especially against desicca- tion and oxidising compounds, whereas a Desulfovibrio sp. strain exhibit a relatively high radiation resistance. The future experiments aim at the identification of the underlying cellu- lar and molecular mechanisms and the comparison to other new isolates from Mars analogue environments on Earth in the MASE project

Kombucha multimicrobial community under simulated spaceflight and martian conditions

Kombucha microbial community (KMC) produces a cellulose-based biopolymer of industrial importance and a probiotic beverage. KMC-derived cellulose-based pellicle film is known as a highly adaptive microbial macrocolony - a stratified community of prokaryotes and eukaryotes. In the framework of the multipurpose international astrobiological project "BIOlogy and Mars Experiment (BIOMEX)," which aims to study the vitality of prokaryotic and eukaryotic organisms and the stability of selected biomarkers in low Earth orbit and in a Mars-like environment, a cellulose polymer structural integrity will be assessed as a biomarker and biotechnological nanomaterial. In a preflight assessment program for BIOMEX, the mineralized bacterial cellulose did not exhibit significant changes in the structure under all types of tests. KMC members that inhabit the cellulose-based pellicle exhibited a high survival rate; however, the survival capacity depended on a variety of stressors such as the vacuum of space, a Mars-like atmosphere, UVC radiation, and temperature fluctuations. The critical limiting factor for microbial survival was high-dose UV irradiation. In the tests that simulated a 1-year mission of exposure outside the International Space Station, the core populations of bacteria and yeasts survived and provided protection against UV; however, the microbial density of the populations overall was reduced, which was revealed by implementation of culture-dependent and culture-independent methods. Reduction of microbial richness was also associated with a lower accumulation of chemical elements in the cellulose-based pellicle film, produced by microbiota that survived in the post-test experiments, as compared to untreated cultures that populated the film.This study was supported by National Academy of Sciences of Ukraine (grant 47/2012-15). The pre-flight programs EVTs and SVTs for the EXPOSE-R2 mission were supported by the European Space Agency.http://www.liebertpub.com/overview/astrobiology/992018-05-30hj2017Biochemistr