scholarly journals Iron Ion Particle Radiation Resistance of Dried Colonies of Cryomyces antarcticus Embedded in Martian Regolith Analogues

Life ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 306
Author(s):  
Lorenzo Aureli ◽  
Claudia Pacelli ◽  
Alessia Cassaro ◽  
Akira Fujimori ◽  
Ralf Moeller ◽  
...  
Keyword(s):  
Extreme Environments ◽  
Life Forms ◽  
Culture Collection ◽  
Dna Integrity ◽  
Martian Surface ◽  
Particle Radiation ◽  
Shallow Subsurface ◽  
Subsurface Environments ◽  
High Doses ◽  
Martian Regolith

Among the celestial bodies in the Solar System, Mars currently represents the main target for the search for life beyond Earth. However, its surface is constantly exposed to high doses of cosmic rays (CRs) that may pose a threat to any biological system. For this reason, investigations into the limits of resistance of life to space relevant radiation is fundamental to speculate on the chance of finding extraterrestrial organisms on Mars. In the present work, as part of the STARLIFE project, the responses of dried colonies of the black fungus Cryomyces antarcticus Culture Collection of Fungi from Extreme Environments (CCFEE) 515 to the exposure to accelerated iron (LET: 200 keV/μm) ions, which mimic part of CRs spectrum, were investigated. Samples were exposed to the iron ions up to 1000 Gy in the presence of Martian regolith analogues. Our results showed an extraordinary resistance of the fungus in terms of survival, recovery of metabolic activity and DNA integrity. These experiments give new insights into the survival probability of possible terrestrial-like life forms on the present or past Martian surface and shallow subsurface environments.

scholarly journals Insights into the Survival Capabilities of Cryomyces antarcticus Hydrated Colonies after Exposure to Fe Particle Radiation

2021 ◽  
Vol 7 (7) ◽  
pp. 495
Author(s):  
Pacelli Claudia ◽  
Cassaro Alessia ◽  
Loke M. Siong ◽  
Aureli Lorenzo ◽  
Moeller Ralf ◽  
...  
Keyword(s):  
Prolonged Exposure ◽  
Life Forms ◽  
Modern Concept ◽  
Atmospheric Conditions ◽  
Particle Radiation ◽  
Dna Damages ◽  
Terrestrial Life ◽  
High Doses ◽  
Chemical Conditions ◽  
The Impact

The modern concept of the evolution of Mars assumes that life could potentially have originated on the planet Mars, possibly during the end of the late heavy bombardment, and could then be transferred to other planets. Since then, physical and chemical conditions on Mars changed and now strongly limit the presence of terrestrial-like life forms. These adverse conditions include scarcity of liquid water (although brine solutions may exist), low temperature and atmospheric pressure, and cosmic radiation. Ionizing radiation is very important among these life-constraining factors because it damages DNA and other cellular components, particularly in liquid conditions where radiation-induced reactive oxidants diffuse freely. Here, we investigated the impact of high doses (up to 2 kGy) of densely-ionizing (197.6 keV/µm), space-relevant iron ions (corresponding on the irradiation that reach the uppermost layer of the Mars subsurface) on the survival of an extremophilic terrestrial organism—Cryomyces antarcticus—in liquid medium and under atmospheric conditions, through different techniques. Results showed that it survived in a metabolically active state when subjected to high doses of Fe ions and was able to repair eventual DNA damages. It implies that some terrestrial life forms can withstand prolonged exposure to space-relevant ion radiation.

scholarly journals Novel water source for endolithic life in the hyperarid core of the Atacama Desert

2012 ◽  
Vol 9 (6) ◽  
pp. 2275-2286 ◽  
Author(s):  
J. Wierzchos ◽  
A. F. Davila ◽  
I. M. Sánchez-Almazo ◽  
M. Hajnos ◽  
R. Swieboda ◽  
...  
Keyword(s):  
Liquid Water ◽  
Capillary Condensation ◽  
Extreme Environments ◽  
Atacama Desert ◽  
Water Source ◽  
Life Forms ◽  
Alternative Source ◽  
Biological Adaptation ◽  
Salt Flats ◽  
Life On Earth

Abstract. The hyperarid core of the Atacama Desert, Chile, is possibly the driest and most life-limited place on Earth, yet endolithic microorganisms thrive inside halite pinnacles that are part of ancient salt flats. The existence of this microbial community in an environment that excludes any other life forms suggests biological adaptation to high salinity and desiccation stress, and indicates an alternative source of water for life other than rainfall, fog or dew. Here, we show that halite endoliths obtain liquid water through spontaneous capillary condensation at relative humidity (RH) much lower than the deliquescence RH of NaCl. We describe how this condensation could occur inside nano-pores smaller than 100 nm, in a newly characterized halite phase that is intimately associated with the endolithic aggregates. This nano-porous phase helps retain liquid water for long periods of time by preventing its evaporation even in conditions of utmost dryness. Our results explain how life has colonized and adapted to one of the most extreme environments on our planet, expanding the water activity envelope for life on Earth, and broadening the spectrum of possible habitats for life beyond our planet.

scholarly journals Seismic investigations of the Martian near-surface at the InSight landing site

2020 ◽  
Author(s):  
Cedric Schmelzbach ◽  
Nienke Brinkman ◽  
David Sollberger ◽  
Sharon Kedar ◽  
Matthias Grott ◽  
...  
Keyword(s):  
Deep Structure ◽  
Landing Site ◽  
P Wave ◽  
Mission Design ◽  
Normal Operation ◽  
Seismic Signals ◽  
Martian Surface ◽  
Broadband Seismometer ◽  
Near Surface ◽  
Martian Regolith

<p>The InSight ultra-sensitive broadband seismometer package (SEIS) was installed on the Martian surface with the goal to study the seismicity on Mars and the deep interior of the Planet. A second surface-based instrument, the heat flow and physical properties package HP<sup>3</sup>, was placed on the Martian ground about 1.1 m away from SEIS. HP<sup>3</sup> includes a self-hammering probe called the ‘mole’ to measure the heat coming from Mars' interior at shallow depth to reveal the planet's thermal history. While SEIS was designed to study the deep structure of Mars, seismic signals such as the hammering ‘noise’ as well as ambient and other instrument-generated vibrations allow us to investigate the shallow subsurface. The resultant near-surface elastic property models provide additional information to interpret the SEIS data and allow extracting unique geotechnical information on the Martian regolith.</p><p>The seismic signals recorded during HP<sup>3</sup> mole operations provide information about the mole attitude and health as well as shed light on the near-surface, despite the fact that the HP<sup>3 </sup>mole continues to have difficulty penetrating below 40 cm (one mole length). The seismic investigation of the HP<sup>3</sup> hammering signals, however, was not originally planned during mission design and hence faced several technical challenges. For example, the anti-aliasing filters of the seismic-data acquisition chain were adapted when recording the mole hammering to allow recovering information above the nominal Nyquist frequency. In addition, the independently operating SEIS, HP<sup>3</sup> and lander clocks had to be correlated more frequently than in normal operation to enable high-precision timing.</p><p>To date, the analysis of the hammering signals allowed us to constrain the bulk P-wave velocity of the volume between the mole tip and SEIS (top 30 cm) to around 120 m/s. This low velocity value is compatible with laboratory tests performed on Martian regolith analogs with a density of around 1500 kg/m<sup>3</sup>. Furthermore, the SEIS leveling system resonances, seismic recordings of atmospheric pressure signals, HP<sup>3</sup> housekeeping data, and imagery provide additional constraints to establish a first seismic model of the shallow (topmost meters) subsurface at the landing site.</p>

scholarly journals Methanogenic Archaea Can Produce Methane in Deliquescence-Driven Mars Analog Environments

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Deborah Maus ◽  
Jacob Heinz ◽  
Janosch Schirmack ◽  
Alessandro Airo ◽  
Samuel P. Kounaves ◽  
...  
Keyword(s):  
Metabolic Activity ◽  
Methanogenic Archaea ◽  
Dynamic Environments ◽  
Martian Surface ◽  
Near Surface ◽  
Methanosarcina Mazei ◽  
Mars Analog ◽  
Recurring Slope Lineae ◽  
Martian Regolith ◽  
First Time

AbstractThe current understanding of the Martian surface indicates that briny environments at the near-surface are temporarily possible, e.g. in the case of the presumably deliquescence-driven Recurring Slope Lineae (RSL). However, whether such dynamic environments are habitable for terrestrial organisms remains poorly understood. This hypothesis was tested by developing a Closed Deliquescence System (CDS) consisting of a mixture of desiccated Martian Regolith Analog (MRA) substrate, salts, and microbial cells, which over the course of days became wetted through deliquescence. The methane produced via metabolic activity for three methanogenic archaea: Methanosarcina mazei, M. barkeri and M. soligelidi, was measured after exposing them to three different MRA substrates using either NaCl or NaClO4 as a hygroscopic salt. Our experiments showed that (1) M. soligelidi rapidly produced methane at 4 °C, (2) M. barkeri produced methane at 28 °C though not at 4 °C, (3) M. mazei was not metabolically reactivated through deliquescence, (4) none of the species produced methane in the presence of perchlorate, and (5) all species were metabolically most active in the phyllosilicate-containing MRA. These results emphasize the importance of the substrate, microbial species, salt, and temperature used in the experiments. Furthermore, we show here for the first time that water provided by deliquescence alone is sufficient to rehydrate methanogenic archaea and to reactivate their metabolism under conditions roughly analogous to the near-subsurface Martian environment.

scholarly journals High pressures increase α-chymotrypsin enzyme activity under perchlorate stress

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Stewart Gault ◽  
Michel W. Jaworek ◽  
Roland Winter ◽  
Charles S. Cockell
Keyword(s):  
High Pressure ◽  
Enzyme Activity ◽  
Phase Space ◽  
High Pressures ◽  
Extreme Environments ◽  
Combined Effects ◽  
Deep Subsurface ◽  
Subsurface Environments ◽  
Dissolved Ions ◽  
High Concentrations

Abstract Deep subsurface environments can harbour high concentrations of dissolved ions, yet we know little about how this shapes the conditions for life. We know even less about how the combined effects of high pressure influence the way in which ions constrain the possibilities for life. One such ion is perchlorate, which is found in extreme environments on Earth and pervasively on Mars. We investigated the interactions of high pressure and high perchlorate concentrations on enzymatic activity. We demonstrate that high pressures increase α-chymotrypsin enzyme activity even in the presence of high perchlorate concentrations. Perchlorate salts were shown to shift the folded α-chymotrypsin phase space to lower temperatures and pressures. The results presented here may suggest that high pressures increase the habitability of environments under perchlorate stress. Therefore, deep subsurface environments that combine these stressors, potentially including the subsurface of Mars, may be more habitable than previously thought.

scholarly journals Data Analyses and new Findings Indicate a Primordial Neurotropic Pathogen Evolved into Infectious Causes of Several CNS Neurodegenerative Diseases

2017 ◽  
Author(s):  
William J. Todd ◽  
Lidiya Dubytska ◽  
Peter J. Mottram ◽  
Xiaochu Wu ◽  
Yuliya Y. Sokolova
Keyword(s):  
Prion Diseases ◽  
Extreme Environments ◽  
Life Forms ◽  
Transmissible Spongiform Encephalopathies ◽  
Emerging Infections ◽  
Spongiform Encephalopathies ◽  
Cytopathic Effects ◽  
Selective Pressures ◽  
New Findings ◽  
Research Resources

AbstractThe extraordinary genetic flexibility of microorganisms enables their evolution into diverse forms expressing unanticipated structures and functions. Typically, they evolve in response to selective pressures of challenging niches, enabling their evolution and survival in extreme environments wherein life forms were not thought to exist. Approaching the problem of persistent neurodegenerative CNS infections as a challenging niche for pathogen evolution led to uncovering microorganisms which expand concepts of microbial diversity. These organisms are proposed as hybrid pathogens. They express two separate sets of structures and functions: viruslike properties when intracellular, and yet also reproduce as unique prokaryotes when outside the host. Their recovery opens new opportunities to comprehend the remarkable diversity of pathogens and elucidate etiologies of unresolved CNS neurodegenerative infections. Cells infected with these agents produce virus-like particles, inclusions and cytopathic effects consistent with biopsy studies of multiple sclerosis (MS), the α-synucleinopathies, and the transmissible spongiform encephalopathies (TSE) or prion diseases. The principle agents described were recovered from sheep with scrapie and are available via the Biodefense and Emerging Infections Research Resources Repository. Comparative studies with SMCA, a tick isolate inducing neurodegeneration in lab animal models, are included as supportive evidence.

scholarly journals A Low-Pressure, N2/CO2 Atmosphere Is Suitable for Cyanobacterium-Based Life-Support Systems on Mars

2021 ◽  
Vol 12 ◽  
Author(s):  
Cyprien Verseux ◽  
Christiane Heinicke ◽  
Tiago P. Ramalho ◽  
Jonathan Determann ◽  
Malte Duckhorn ◽  
...  
Keyword(s):  
Life Support ◽  
Support Systems ◽  
Heterotrophic Bacterium ◽  
Low Pressure ◽  
Atmospheric Conditions ◽  
Martian Surface ◽  
Life Support Systems ◽  
Secondary Consumers ◽  
Biological Life Support ◽  
Martian Regolith

The leading space agencies aim for crewed missions to Mars in the coming decades. Among the associated challenges is the need to provide astronauts with life-support consumables and, for a Mars exploration program to be sustainable, most of those consumables should be generated on site. Research is being done to achieve this using cyanobacteria: fed from Mars's regolith and atmosphere, they would serve as a basis for biological life-support systems that rely on local materials. Efficiency will largely depend on cyanobacteria's behavior under artificial atmospheres: a compromise is needed between conditions that would be desirable from a purely engineering and logistical standpoint (by being close to conditions found on the Martian surface) and conditions that optimize cyanobacterial productivity. To help identify this compromise, we developed a low-pressure photobioreactor, dubbed Atmos, that can provide tightly regulated atmospheric conditions to nine cultivation chambers. We used it to study the effects of a 96% N2, 4% CO2 gas mixture at a total pressure of 100 hPa on Anabaena sp. PCC 7938. We showed that those atmospheric conditions (referred to as MDA-1) can support the vigorous autotrophic, diazotrophic growth of cyanobacteria. We found that MDA-1 did not prevent Anabaena sp. from using an analog of Martian regolith (MGS-1) as a nutrient source. Finally, we demonstrated that cyanobacterial biomass grown under MDA-1 could be used for feeding secondary consumers (here, the heterotrophic bacterium E. coli W). Taken as a whole, our results suggest that a mixture of gases extracted from the Martian atmosphere, brought to approximately one tenth of Earth's pressure at sea level, would be suitable for photobioreactor modules of cyanobacterium-based life-support systems. This finding could greatly enhance the viability of such systems on Mars.

scholarly journals Habitability of Mars: How Welcoming Are the Surface and Subsurface to Life on the Red Planet?

Geosciences ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 361
Author(s):  
Aleksandra Checinska Sielaff ◽  
Stephanie A. Smith
Keyword(s):  
Scientific Community ◽  
Extreme Environments ◽  
Environmental Studies ◽  
Future Research ◽  
Martian Surface ◽  
Microbial Life ◽  
Subglacial Lake ◽  
The Past ◽  
Current State ◽  
Present Life

Mars is a planet of great interest in the search for signatures of past or present life beyond Earth. The years of research, and more advanced instrumentation, have yielded a lot of evidence which may be considered by the scientific community as proof of past or present habitability of Mars. Recent discoveries including seasonal methane releases and a subglacial lake are exciting, yet challenging findings. Concurrently, laboratory and environmental studies on the limits of microbial life in extreme environments on Earth broaden our knowledge of the possibility of Mars habitability. In this review, we aim to: (1) Discuss the characteristics of the Martian surface and subsurface that may be conducive to habitability either in the past or at present; (2) discuss laboratory-based studies on Earth that provide us with discoveries on the limits of life; and (3) summarize the current state of knowledge in terms of direction for future research.

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