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Fischer FC, Schulze-Makuch D, Heinz J. Microbial preference for chlorate over perchlorate under simulated shallow subsurface Mars-like conditions. Sci Rep 2024; 14:11537. [PMID: 38773211 PMCID: PMC11109124 DOI: 10.1038/s41598-024-62346-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 05/15/2024] [Indexed: 05/23/2024] Open
Abstract
The Martian surface and shallow subsurface lacks stable liquid water, yet hygroscopic salts in the regolith may enable the transient formation of liquid brines. This study investigated the combined impact of water scarcity, UV exposure, and regolith depth on microbial survival under Mars-like environmental conditions. Both vegetative cells of Debaryomyces hansenii and Planococcus halocryophilus, alongside with spores of Aspergillus niger, were exposed to an experimental chamber simulating Martian environmental conditions (constant temperatures of about - 11 °C, low pressure of approximately 6 mbar, a CO2 atmosphere, and 2 h of daily UV irradiation). We evaluated colony-forming units (CFU) and water content at three different regolith depths before and after exposure periods of 3 and 7 days, respectively. Each organism was tested under three conditions: one without the addition of salts to the regolith, one containing sodium chlorate, and one with sodium perchlorate. Our results reveal that the residual water content after the exposure experiments increased with regolith depth, along with the organism survival rates in chlorate-containing and salt-free samples. The survival rates of the three organisms in perchlorate-containing regolith were consistently lower for all organisms and depths compared to chlorate, with the most significant difference being observed at a depth of 10-12 cm, which corresponds to the depth with the highest residual water content. The postulated reason for this is an increase in the salt concentration at this depth due to the freezing of water, showing that for these organisms, perchlorate brines are more toxic than chlorate brines under the experimental conditions. This underscores the significance of chlorate salts when considering the habitability of Martian environments.
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Affiliation(s)
- Florian Carlo Fischer
- Center for Astronomy and Astrophysics, RG Astrobiology, Technische Universität Berlin, Berlin, Germany
| | - Dirk Schulze-Makuch
- Center for Astronomy and Astrophysics, RG Astrobiology, Technische Universität Berlin, Berlin, Germany
- GFZ German Research Center for Geosciences, Section Geomicrobiology, Potsdam, Germany
- Department of Plankton and Microbial Ecology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Stechlin, Germany
| | - Jacob Heinz
- Center for Astronomy and Astrophysics, RG Astrobiology, Technische Universität Berlin, Berlin, Germany.
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2
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Horstmann L, Lipus D, Bartholomäus A, Arens F, Airo A, Ganzert L, Zamorano P, Schulze-Makuch D, Wagner D. Persistent microbial communities in hyperarid subsurface habitats of the Atacama Desert: Insights from intracellular DNA analysis. PNAS NEXUS 2024; 3:pgae123. [PMID: 38655503 PMCID: PMC11037274 DOI: 10.1093/pnasnexus/pgae123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 03/12/2024] [Indexed: 04/26/2024]
Abstract
Desert environments constitute one of the largest and yet most fragile ecosystems on Earth. Under the absence of regular precipitation, microorganisms are the main ecological component mediating nutrient fluxes by using soil components, like minerals and salts, and atmospheric gases as a source for energy and water. While most of the previous studies on microbial ecology of desert environments have focused on surface environments, little is known about microbial life in deeper sediment layers. Our study is extending the limited knowledge about microbial communities within the deeper subsurface of the hyperarid core of the Atacama Desert. By employing intracellular DNA extraction and subsequent 16S rRNA sequencing of samples collected from a soil pit in the Yungay region of the Atacama Desert, we unveiled a potentially viable microbial subsurface community residing at depths down to 4.20 m. In the upper 80 cm of the playa sediments, microbial communities were dominated by Firmicutes taxa showing a depth-related decrease in biomass correlating with increasing amounts of soluble salts. High salt concentrations are possibly causing microbial colonization to cease in the lower part of the playa sediments between 80 and 200 cm depth. In the underlying alluvial fan deposits, microbial communities reemerge, possibly due to gypsum providing an alternative water source. The discovery of this deeper subsurface community is reshaping our understanding of desert soils, emphasizing the need to consider subsurface environments in future explorations of arid ecosystems.
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Affiliation(s)
- Lucas Horstmann
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, 14473 Potsdam, Germany
- Department Experimental Phycology and Culture Collection of Algae (EPSAG), Albrecht-von-Haller-Institute for Plant Sciences, Georg August University Göttingen, 37073 Göttingen, Germany
| | - Daniel Lipus
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, 14473 Potsdam, Germany
| | - Alexander Bartholomäus
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, 14473 Potsdam, Germany
| | - Felix Arens
- Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, 10623 Berlin, Germany
| | - Alessandro Airo
- Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, 10115 Berlin, Germany
| | - Lars Ganzert
- Department of Plankton and Microbial Ecology, Leibniz Institute of Freshwater Ecology and Inland Fisheries, 16775 Stechlin, Germany
| | - Pedro Zamorano
- Laboratorio de Microorganismos Extremófilos, University of Antofagasta, Antofagasta 02800, Chile
| | - Dirk Schulze-Makuch
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, 14473 Potsdam, Germany
- Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, 10623 Berlin, Germany
- Department of Plankton and Microbial Ecology, Leibniz Institute of Freshwater Ecology and Inland Fisheries, 16775 Stechlin, Germany
| | - Dirk Wagner
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, 14473 Potsdam, Germany
- Institute of Geosciences, University of Potsdam, 14476 Potsdam, Germany
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3
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Schulze-Makuch D, Irwin LN, Irwin T. Proposed Missions to Collect Samples for Analyzing Evidence of Life in the Venusian Atmosphere. ASTROBIOLOGY 2024; 24:397-406. [PMID: 37852009 DOI: 10.1089/ast.2022.0134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
The recent and still controversial claim of phosphine detection in the venusian atmosphere has reignited consideration of whether microbial life might reside in its cloud layers. If microbial life were to exist within Venus' cloud deck, these microorganisms would have to be multi-extremophiles enclosed within the cloud aerosol particles. The most straightforward approach for resolving the question of their existence is to obtain samples of the cloud particles and analyze their interior. While developing technology has made sophisticated in situ analysis possible, more detailed information could be obtained by examining samples with instrumentation in dedicated ground-based facilities. Ultimately, therefore, Venus Cloud-level Sample Return Missions will likely be required to resolve the question of whether living organisms exist in the clouds of Venus. Two multiphase mission concepts are currently under development for combining in situ analyses with a sample return component. The Venus Life Finder architecture proposes collection of cloud particles in a compartment suspended from a balloon that floats for weeks at the desired altitude, while the Novel solUtion for Venus explOration and Lunar Exploitation (NUVOLE) concept involves a glider that cruises within the cloud deck for 1200 km collecting cloud aerosol particles through the key regions of interest. Both architectures propose a rocket-driven ascent with the acquired samples transported to a high venusian orbit as a prelude to returning to Earth or the Moon. Both future conceptual missions with their combined phases will contribute valuable information relative to the habitability of the clouds at Venus, but their fulfillment is decades away. We suggest that, in the meantime, a simplification of a glider cloud-level sample collection scenario could be accomplished in a shorter development time at a lower cost. Even if the cloud particles are not organic and show no evidence of living organisms, they would reveal critical insights about the natural history and evolution of Venus.
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Affiliation(s)
- Dirk Schulze-Makuch
- Astrobiology Group, ZAA, Technical University Berlin, Berlin, Germany
- Section Geomicrobiology, GFZ German Research Center for Geosciences, Potsdam, Germany
- Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Stechlin, Germany
- School of the Environment, Washington State University, Pullman, Washington, USA
| | - Louis N Irwin
- Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas, USA
| | - Troy Irwin
- Oasis Systems, LLC, San Antonio, Texas, USA
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4
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Bonaccorsi R, Glass B, Moreno-Paz M, García-Villadangos M, Warren-Rhodes K, Parro V, Manchado JM, Wilhelm MB, McKay CP. In Situ Real-Time Monitoring for Aseptic Drilling: Lessons Learned from the Atacama Rover Astrobiology Drilling Studies Contamination Control Strategy and Implementation and Application to the Icebreaker Mars Life Detection Mission. ASTROBIOLOGY 2023; 23:1303-1336. [PMID: 38133823 DOI: 10.1089/ast.2022.0133] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
In 2019, the Atacama Rover Astrobiology Drilling Studies (ARADS) project field-tested an autonomous rover-mounted robotic drill prototype for a 6-Sol life detection mission to Mars (Icebreaker). ARADS drilled Mars-like materials in the Atacama Desert (Chile), one of the most life-diminished regions on Earth, where mitigating contamination transfer into life-detection instruments becomes critical. Our Contamination Control Strategy and Implementation (CCSI) for the Sample Handling and Transfer System (SHTS) hardware (drill, scoop and funnels) included out-of-simulation protocol testing (out-of-sim) for hardware decontamination and verification during the 6-Sol simulation (in-sim). The most effective five-step decontamination combined safer-to-use sterilants (3%_hydrogen-peroxide-activated 5%_sodium-hypochlorite), and in situ real-time verification by adenosine triphosphate (ATP) and Signs of Life Detector (SOLID) Fluorescence Immunoassay for characterization hardware bioburden and airborne contaminants. The 20- to 40-min protocol enabled a 4-log bioburden reduction down to <0.1 fmoles ATP detection limit (funnels and drill) to 0.2-0.7 fmoles (scoop) of total ATP. The (post-cleaning) hardware background was 0.3 to 1-2 attomoles ATP/cm2 (cleanliness benchmark background values) equivalent to ca. 1-10 colony forming unit (CFU)/cm2. Further, 60-100% of the in-sim hardware background was ≤3-4 bacterial cells/cm2, the threshold limit for Class <7 aseptic operations. Across the six Sols, the flux of airborne contaminants to the drill sites was ∼5 and ∼22 amoles ATP/(cm2·day), accounting for an unexpectedly high Fluorescence Intensity (FI) signal (FI: ∼6000) against aquatic cyanobacteria, but negligible anthropogenic contribution. The SOLID immunoassay also detected microorganisms from multiple habitats across the Atacama Desert (anoxic, alkaline/acidic microenvironments in halite fields, playas, and alluvial fans) in both airborne and post-cleaning hardware background. Finally, the hardware ATP background was 40-250 times lower than the ATP in cores. Similarly, the FI peaks (FImax) against the microbial taxa and molecular biomarkers detected in the post-cleaned hardware (FI: ∼1500-1600) were 5-10 times lower than biomarkers in drilled sediments, excluding significant interference with putative biomarker found in cores. Similar protocols enable the acquisition of contamination-free materials for ultra-sensitive instruments analysis and the integrity of scientific results. Their application can augment our scientific knowledge of the distribution of cryptic life on Mars-like grounds and support life-detection robotic and human-operated missions to Mars.
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Affiliation(s)
- Rosalba Bonaccorsi
- SETI Institute, Mountain View, California, USA
- NASA Ames Research Center, Moffett Field, California, USA
| | - Brian Glass
- NASA Ames Research Center, Moffett Field, California, USA
| | - Mercedes Moreno-Paz
- Department of Molecular Evolution, Centro de Astrobiología (INTA-CSIC), Madrid, Spain
| | | | - Kimberley Warren-Rhodes
- SETI Institute, Mountain View, California, USA
- NASA Ames Research Center, Moffett Field, California, USA
| | - Victor Parro
- Department of Molecular Evolution, Centro de Astrobiología (INTA-CSIC), Madrid, Spain
| | - Juan Manuel Manchado
- Department of Molecular Evolution, Centro de Astrobiología (INTA-CSIC), Madrid, Spain
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5
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Huang W, Stamos BN. Portable light weight open tubular ion chromatograph for field determination of environmental anions. J Chromatogr A 2023; 1711:464464. [PMID: 37871504 DOI: 10.1016/j.chroma.2023.464464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 10/10/2023] [Accepted: 10/17/2023] [Indexed: 10/25/2023]
Abstract
We report a battery powered non-suppressed open tubular ion chromatograph (NSOTIC) that weighs less than 3 kg with on-board rechargeable lithium-ion batteries that provide power for 18 h of operation. It is contained in an aluminum case measuring 30 × 25 × 16 cm. Separation relies on open tubular (OT) chromatographic columns which eliminate the need for high pressure pumps, drastically reducing weight and complexity. Eluent consumption is less than 100 µL per separation. Eluent is supplied from a pressurized vessel via a voltage-controlled electronic pressure controller. Flow rates are typically <200 nL/min which allows a single 16-20 g gas cartridge to perform hundreds of separations. Two anions, chloride and nitrate, in Atacama soil samples were field determined by running the portable NSOTIC. More samples were lab analyzed by commercial IC and IC/MS-MS (only perchlorate due to its low concentration level). To demonstrate the feasibility of running NSOTIC on sample analysis, samples were tested by both non-portable and portable NSOTIC.
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Affiliation(s)
- Weixiong Huang
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan 430078, Hubei, China; Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX 76019-0065, United States.
| | - Brian N Stamos
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX 76019-0065, United States
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6
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Phillips MS, Moersch JE, Cabrol NA, Candela A, Wettergreen D, Warren-Rhodes K, Hinman NW. Planetary Mapping Using Deep Learning: A Method to Evaluate Feature Identification Confidence Applied to Habitats in Mars-Analog Terrain. ASTROBIOLOGY 2023; 23:76-93. [PMID: 36520604 DOI: 10.1089/ast.2022.0014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The goals of Mars exploration are evolving beyond describing environmental habitability at global and regional scales to targeting specific locations for biosignature detection, sample return, and eventual human exploration. An increase in the specificity of scientific goals-from follow the water to find the biosignatures-requires parallel developments in strategies that translate terrestrial Mars-analog research into confident identification of rover-explorable targets on Mars. Precisely how to integrate terrestrial, ground-based analyses with orbital data sets and transfer those lessons into rover-relevant search strategies for biosignatures on Mars remains an open challenge. Here, leveraging small Unmanned Aerial System (sUAS) technology and state-of-the-art fully convolutional neural networks for pixel-wise classification, we present an end-to-end methodology that applies Deep Learning to map geomorphologic units and quantify feature identification confidence. We used this method to assess the identification confidence of rover-explorable habitats in the Mars-analog Salar de Pajonales over a range of spatial resolutions and found that spatial resolutions two times better than are available from Mars would be necessary to identify habitats in this study at the 1-σ (85%) confidence level. The approach we present could be used to compare the identifiability of habitats across Mars-analog environments and focus Mars exploration from the scale of regional habitability to the scale of specific habitats. Our methods could also be adapted to map dome- and ridge-like features on the surface of Mars to further understand their origin and astrobiological potential.
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Affiliation(s)
- Michael S Phillips
- Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, USA
| | - Jeffrey E Moersch
- Department of Earth and Planetary Sciences, The University of Tennessee, Knoxville, Tennessee, USA
| | - Nathalie A Cabrol
- SETI Institute/NASA Ames Research Center, Moffett Field, California, USA
| | - Alberto Candela
- The Robotics Institute, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - David Wettergreen
- The Robotics Institute, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | | | - Nancy W Hinman
- Department of Geosciences, University of Montana, Missoula, Montana, USA
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7
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Naz N, Liu D, Harandi BF, Kounaves SP. Microbial Growth in Martian Soil Simulants Under Terrestrial Conditions: Guiding the Search for Life on Mars. ASTROBIOLOGY 2022; 22:1210-1221. [PMID: 36000998 DOI: 10.1089/ast.2022.0022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The search for life elsewhere in the Universe goes together with the search for liquid water. Life as we know it requires water; however, it is possible for microbial life to exist under hyperarid conditions with a minimal amount of water. We report on the ability of two typical terrestrial bacteria (Escherichia coli B and Eucapsis sp) and two extremophiles (Gloeocapsa-20201027-1 sp and Planococcus halocryophilus) to grow and survive in three martian soil (regolith) simulants (Mohave Mars Simulant-1 [MMS-1] F, Mars Global Simulant-1 [MGS-1], and JSC Mars-1A [JSC]). Survival and growth were assessed over a 21-day period under terrestrial conditions and with water:soil (vol:wt) ratios that varied from 0.25:1 to 5:1. We found that Eucapsis and Gloeocapsa sp grew best in the simulants MMS and JSC, respectively, while P. halocryophilus growth rates were better in the JSC simulant. As expected, E. coli did not show significant growth. Our results indicate that these martian simulants and thus martian regolith, with minimal or no added nutrients or water, can support the growth of extremophiles such as P. halocryphilus and Gloeocapsa. Similar extremophiles on early Mars may have survived to the present in near-surface ecological niches analogous to those where these organisms exist on Earth.
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Affiliation(s)
- Neveda Naz
- Department of Chemistry, Tufts University, Medford, Massachusetts, USA
| | - Dongyu Liu
- Department of Chemistry, Tufts University, Medford, Massachusetts, USA
| | - Bijan F Harandi
- Department of Chemistry, Tufts University, Medford, Massachusetts, USA
| | - Samuel P Kounaves
- Department of Chemistry, Tufts University, Medford, Massachusetts, USA
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8
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Billi D, Blanco Y, Ianneo A, Moreno-Paz M, Aguirre J, Baqué M, Moeller R, de Vera JP, Parro V. Mars-like UV Flux and Ionizing Radiation Differently Affect Biomarker Detectability in the Desert Cyanobacterium Chroococcidiopsis as Revealed by the Life Detector Chip Antibody Microarray. ASTROBIOLOGY 2022; 22:1199-1209. [PMID: 36194868 DOI: 10.1089/ast.2022.0013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The effect of a Mars-like UV flux and γ-radiation on the detectability of biomarkers in dried cells of Chroococcidiopsis sp. CCMEE 029 was investigated using a fluorescence sandwich microarray immunoassay. The production of anti-Chroococcidiopsis antibodies allowed the immunoidentification of a reduced, though still detectable, signal in dried cells mixed with phyllosilicatic and sulfatic Mars regolith simulants after exposure to 6.8 × 105 kJ/m2 of a Mars-like UV flux. No signal was detected in dried cells that were not mixed with minerals after 1.4 × 105 kJ/m2. For γ-radiation (60Co), no detectable variations of the fluorescence signal occurred in dried cells exposed to 113 kGy compared to non-irradiated dried cells. Our results suggest that immunoassay-based techniques could be used to detect life tracers eventually present in the martian subsurface in freshly excavated materials only if shielded from solar UV. The high structural integrity of biomarkers irradiated with γ-radiation that mimics a dose accumulated in 13 Myr at 2 m depth from the martian surface has implications for the potential detectability of similar organic molecules/compounds by future life-detection missions such as the ExoMars Rosalind Franklin rover.
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Affiliation(s)
- Daniela Billi
- University of Rome Tor Vergata, Department of Biology, Rome, Italy
| | - Yolanda Blanco
- Centro de Astrobiología (CAB), CSIC-INTA, Department of Molecular Evolution, Torrejón de Ardoz, Madrid, Spain
| | - Andrea Ianneo
- University of Rome Tor Vergata, Department of Biology, Rome, Italy
| | - Mercedes Moreno-Paz
- Centro de Astrobiología (CAB), CSIC-INTA, Department of Molecular Evolution, Torrejón de Ardoz, Madrid, Spain
| | - Jacobo Aguirre
- Centro de Astrobiología (CAB), CSIC-INTA, Department of Molecular Evolution, Torrejón de Ardoz, Madrid, Spain
| | - Mickael Baqué
- German Aerospace Center (DLR), Institute of Planetary Research, Planetary Laboratories Department, Berlin, Germany
| | - Ralf Moeller
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Cologne, Germany
| | - Jean-Pierre de Vera
- German Aerospace Center (DLR), Space Operations and Astronaut Training, Microgravity User Support Center, Cologne, Germany
| | - Victor Parro
- Centro de Astrobiología (CAB), CSIC-INTA, Department of Molecular Evolution, Torrejón de Ardoz, Madrid, Spain
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9
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Heinz J, Doellinger J, Maus D, Schneider A, Lasch P, Grossart HP, Schulze-Makuch D. Perchlorate-Specific Proteomic Stress Responses of Debaryomyces hansenii Could Enable Microbial Survival in Martian Brines. Environ Microbiol 2022; 24:5051-5065. [PMID: 35920032 DOI: 10.1111/1462-2920.16152] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 07/27/2022] [Indexed: 11/29/2022]
Abstract
If life exists on Mars, it would face several challenges including the presence of perchlorates, which destabilize biomacromolecules by inducing chaotropic stress. However, little is known about perchlorate toxicity for microorganism on the cellular level. Here we present the first proteomic investigation on the perchlorate-specific stress responses of the halotolerant yeast Debaryomyces hansenii and compare these to generally known salt stress adaptations. We found that the responses to NaCl and NaClO4 -induced stresses share many common metabolic features, e.g., signaling pathways, elevated energy metabolism, or osmolyte biosynthesis. Nevertheless, several new perchlorate-specific stress responses could be identified, such as protein glycosylation and cell wall remodulations, presumably in order to stabilize protein structures and the cell envelope. These stress responses would also be relevant for life on Mars, which - given the environmental conditions - likely developed chaotropic defense strategies such as stabilized confirmations of biomacromolecules and the formation of cell clusters. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Jacob Heinz
- Center for Astronomy and Astrophysics, RG Astrobiology, Technische Universität Berlin, Berlin, Germany
| | - Joerg Doellinger
- Robert Koch-Institute, Centre for Biological Threats and Special Pathogens, Proteomics and Spectroscopy (ZBS6), Berlin, Germany
| | - Deborah Maus
- Robert Koch-Institute, Metabolism of Microbial Pathogens (NG2), Berlin, Germany
| | - Andy Schneider
- Robert Koch-Institute, Centre for Biological Threats and Special Pathogens, Proteomics and Spectroscopy (ZBS6), Berlin, Germany
| | - Peter Lasch
- Robert Koch-Institute, Centre for Biological Threats and Special Pathogens, Proteomics and Spectroscopy (ZBS6), Berlin, Germany
| | - Hans-Peter Grossart
- Department of Plankton and Microbial Ecology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), 16775 Stechlin, Germany.,Institute for Biochemistry and Biology, Potsdam University, Potsdam, Germany
| | - Dirk Schulze-Makuch
- Center for Astronomy and Astrophysics, RG Astrobiology, Technische Universität Berlin, Berlin, Germany.,Department of Plankton and Microbial Ecology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), 16775 Stechlin, Germany.,GFZ German Research Center for Geosciences, Section Geomicrobiology, Potsdam, Germany.,School of the Environment, Washington State University, Pullman, Washington, USA
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10
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Weingarten EA, Zee PC, Jackson CR. Microbial Communities in Saltpan Sediments Show Tolerance to Mars Analog Conditions, but Susceptibility to Chloride and Perchlorate Toxicity. ASTROBIOLOGY 2022; 22:838-850. [PMID: 35731161 PMCID: PMC9464085 DOI: 10.1089/ast.2021.0132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 02/28/2022] [Indexed: 06/15/2023]
Abstract
Brines at or near the surface of present-day Mars are a potential explanation for seasonally recurring dark streaks on the walls of craters, termed recurring slope lineae (RSL). Deliquescence and freezing point depression are possible drivers of brine stability, attributable to the high salinity observed in martian regolith including chlorides and perchlorates. Investigation of life, which may inhabit RSL, and the cellular mechanisms necessary for survival, must consider the tolerance of highly variable hydration, freeze-thaw cycles, and high osmolarity in addition to the anaerobic, oligotrophic, and irradiated environment. We propose the saltpan, an ephemeral, hypersaline wetland as an analogue for putative RSL hydrology. Saltpan sediment archaeal and bacterial communities showed tolerance of the Mars-analogous atmosphere, hydration, minerology, salinity, and temperature. Although active growth and a shift to well-adapted taxa were observed, susceptibility to low-concentration chloride and perchlorate addition suggested that such a composition was insufficient for beneficial water retention relative to added salt stress.
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Affiliation(s)
- Eric A. Weingarten
- Department of Biology, University of Mississippi, University, Mississippi, USA
- U.S. Army Engineer Research and Development Center, Vicksburg, Mississippi, USA
| | - Peter C. Zee
- Department of Biology, University of Mississippi, University, Mississippi, USA
| | - Colin R. Jackson
- Department of Biology, University of Mississippi, University, Mississippi, USA
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11
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Vignale FA, Lencina AI, Stepanenko TM, Soria MN, Saona LA, Kurth D, Guzmán D, Foster JS, Poiré DG, Villafañe PG, Albarracín VH, Contreras M, Farías ME. Lithifying and Non-Lithifying Microbial Ecosystems in the Wetlands and Salt Flats of the Central Andes. MICROBIAL ECOLOGY 2022; 83:1-17. [PMID: 33730193 DOI: 10.1007/s00248-021-01725-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 02/22/2021] [Indexed: 06/12/2023]
Abstract
The wetlands and salt flats of the Central Andes region are unique extreme environments as they are located in high-altitude saline deserts, largely influenced by volcanic activity. Environmental factors, such as ultraviolet (UV) radiation, arsenic content, high salinity, low dissolved oxygen content, extreme daily temperature fluctuation, and oligotrophic conditions, resemble the early Earth and potentially extraterrestrial conditions. The discovery of modern microbialites and microbial mats in the Central Andes during the past decade has increased the interest in this area as an early Earth analog. In this work, we review the current state of knowledge of Central Andes region environments found within lakes, small ponds or puquios, and salt flats of Argentina, Chile, and Bolivia, many of them harboring a diverse range of microbial communities that we have termed Andean Microbial Ecosystems (AMEs). We have integrated the data recovered from all the known AMEs and compared their biogeochemistry and microbial diversity to achieve a better understanding of them and, consequently, facilitate their protection.
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Affiliation(s)
- Federico A Vignale
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales Microbiológicos (PROIMI)-CCT-CONICET, San Miguel de Tucumán, Tucumán, Argentina
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN)-CONICET, Universidad de Buenos Aires (UBA), Buenos Aires, Argentina
| | - Agustina I Lencina
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales Microbiológicos (PROIMI)-CCT-CONICET, San Miguel de Tucumán, Tucumán, Argentina
| | - Tatiana M Stepanenko
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales Microbiológicos (PROIMI)-CCT-CONICET, San Miguel de Tucumán, Tucumán, Argentina
| | - Mariana N Soria
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales Microbiológicos (PROIMI)-CCT-CONICET, San Miguel de Tucumán, Tucumán, Argentina
| | - Luis A Saona
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales Microbiológicos (PROIMI)-CCT-CONICET, San Miguel de Tucumán, Tucumán, Argentina
| | - Daniel Kurth
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales Microbiológicos (PROIMI)-CCT-CONICET, San Miguel de Tucumán, Tucumán, Argentina
| | - Daniel Guzmán
- Centro de Biotecnología (CBT), Facultad de Ciencias y Tecnología, Universidad Mayor de San Simón (UMSS), Cochabamba, Bolivia
| | - Jamie S Foster
- Space Life Science Lab, Department of Microbiology and Cell Science, University of Florida, Merritt Island, FL, USA
| | - Daniel G Poiré
- Centro de Investigaciones Geológicas (CIG), Universidad Nacional de La Plata (UNLP)-CONICET, La Plata, Argentina
| | - Patricio G Villafañe
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales Microbiológicos (PROIMI)-CCT-CONICET, San Miguel de Tucumán, Tucumán, Argentina
| | - Virginia H Albarracín
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales Microbiológicos (PROIMI)-CCT-CONICET, San Miguel de Tucumán, Tucumán, Argentina
- Centro Integral de Microscopía Electrónica (CIME)-CCT-CONICET, Universidad Nacional de Tucumán (UNT), Tucumán, Argentina
| | | | - María E Farías
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales Microbiológicos (PROIMI)-CCT-CONICET, San Miguel de Tucumán, Tucumán, Argentina.
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12
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Limaye SS, Mogul R, Baines KH, Bullock MA, Cockell C, Cutts JA, Gentry DM, Grinspoon DH, Head JW, Jessup KL, Kompanichenko V, Lee YJ, Mathies R, Milojevic T, Pertzborn RA, Rothschild L, Sasaki S, Schulze-Makuch D, Smith DJ, Way MJ. Venus, an Astrobiology Target. ASTROBIOLOGY 2021; 21:1163-1185. [PMID: 33970019 DOI: 10.1089/ast.2020.2268] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We present a case for the exploration of Venus as an astrobiology target-(1) investigations focused on the likelihood that liquid water existed on the surface in the past, leading to the potential for the origin and evolution of life, (2) investigations into the potential for habitable zones within Venus' present-day clouds and Venus-like exo atmospheres, (3) theoretical investigations into how active aerobiology may impact the radiative energy balance of Venus' clouds and Venus-like atmospheres, and (4) application of these investigative approaches toward better understanding the atmospheric dynamics and habitability of exoplanets. The proximity of Venus to Earth, guidance for exoplanet habitability investigations, and access to the potential cloud habitable layer and surface for prolonged in situ extended measurements together make the planet a very attractive target for near term astrobiological exploration.
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Affiliation(s)
- Sanjay S Limaye
- Space Science and Engineering Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Rakesh Mogul
- Chemistry and Biochemistry Department, Cal Poly Pomona, Pomona, California, USA
| | - Kevin H Baines
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | | | - Charles Cockell
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, Scotland
| | - James A Cutts
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Diana M Gentry
- NASA Ames Research Center, Moffett Field, California, USA
| | | | - James W Head
- Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island, USA
| | | | - Vladimir Kompanichenko
- Institute for Complex Analysis of Regional Problems, Russian Academy of Sciences, Birobidzhan, Russia
| | - Yeon Joo Lee
- Zentrum für Astronomie und Astrophysik, Technical University of Berlin, Berlin, Germany
| | - Richard Mathies
- Chemistry Department and Space Sciences Lab, University of California, Berkeley, Berkeley, California, USA
| | - Tetyana Milojevic
- Department of Biophysical Chemistry, University of Vienna, Vienna, Austria
| | - Rosalyn A Pertzborn
- Space Science and Engineering Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | | | - Satoshi Sasaki
- School of Health Sciences, Tokyo University of Technology, Hachioji, Japan
| | - Dirk Schulze-Makuch
- Center for Astronomy and Astrophysics (ZAA), Technische Universität Berlin, Berlin, Germany
- German Research Centre for Geosciences (GFZ), Potsdam, Germany
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Stechlin, Germany
| | - David J Smith
- NASA Ames Research Center, Moffett Field, California, USA
| | - Michael J Way
- NASA Goddard Institute for Space Studies, New York, New York, USA
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13
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Schulze-Makuch D, Lipus D, Arens FL, Baqué M, Bornemann TLV, de Vera JP, Flury M, Frösler J, Heinz J, Hwang Y, Kounaves SP, Mangelsdorf K, Meckenstock RU, Pannekens M, Probst AJ, Sáenz JS, Schirmack J, Schloter M, Schmitt-Kopplin P, Schneider B, Uhl J, Vestergaard G, Valenzuela B, Zamorano P, Wagner D. Microbial Hotspots in Lithic Microhabitats Inferred from DNA Fractionation and Metagenomics in the Atacama Desert. Microorganisms 2021; 9:microorganisms9051038. [PMID: 34065975 PMCID: PMC8151210 DOI: 10.3390/microorganisms9051038] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/29/2021] [Accepted: 05/05/2021] [Indexed: 01/04/2023] Open
Abstract
The existence of microbial activity hotspots in temperate regions of Earth is driven by soil heterogeneities, especially the temporal and spatial availability of nutrients. Here we investigate whether microbial activity hotspots also exist in lithic microhabitats in one of the most arid regions of the world, the Atacama Desert in Chile. While previous studies evaluated the total DNA fraction to elucidate the microbial communities, we here for the first time use a DNA separation approach on lithic microhabitats, together with metagenomics and other analysis methods (i.e., ATP, PLFA, and metabolite analysis) to specifically gain insights on the living and potentially active microbial community. Our results show that hypolith colonized rocks are microbial hotspots in the desert environment. In contrast, our data do not support such a conclusion for gypsum crust and salt rock environments, because only limited microbial activity could be observed. The hypolith community is dominated by phototrophs, mostly Cyanobacteria and Chloroflexi, at both study sites. The gypsum crusts are dominated by methylotrophs and heterotrophic phototrophs, mostly Chloroflexi, and the salt rocks (halite nodules) by phototrophic and halotolerant endoliths, mostly Cyanobacteria and Archaea. The major environmental constraints in the organic-poor arid and hyperarid Atacama Desert are water availability and UV irradiation, allowing phototrophs and other extremophiles to play a key role in desert ecology.
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Affiliation(s)
- Dirk Schulze-Makuch
- Center for Astronomy and Astrophysics, Technische Universität Berlin, 10623 Berlin, Germany; (F.L.A.); (J.H.); (Y.H.); (J.S.)
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany; (D.L.); (B.S.)
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Department of Experimental Limnology, 16775 Stechlin, Germany
- School of the Environment, Washington State University, Pullman, WA 99163, USA
- Correspondence: (D.S.-M.); (D.W.); Tel.: +49-(30)-314-23736 (D.S.-M.); +49-(331)-288-28800 (D.W.)
| | - Daniel Lipus
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany; (D.L.); (B.S.)
| | - Felix L. Arens
- Center for Astronomy and Astrophysics, Technische Universität Berlin, 10623 Berlin, Germany; (F.L.A.); (J.H.); (Y.H.); (J.S.)
| | - Mickael Baqué
- German Aerospace Center (DLR), Institute of Planetary Research, 12489 Berlin, Germany;
| | - Till L. V. Bornemann
- Environmental Microbiology and Biotechnology, Department of Chemistry, University of Duisburg-Essen, 45141 Essen, Germany; (T.L.V.B.); (J.F.); (R.U.M.); (M.P.); (A.J.P.)
| | - Jean-Pierre de Vera
- German Aerospace Center (DLR), Microgravity User Support Center (MUSC), 51147 Cologne, Germany;
| | - Markus Flury
- Department of Crop and Soil Science, Washington State University, Pullman, WA 99164, USA;
- Department of Crop and Soil Science, Washington State University, Puyallup, WA 98371, USA
| | - Jan Frösler
- Environmental Microbiology and Biotechnology, Department of Chemistry, University of Duisburg-Essen, 45141 Essen, Germany; (T.L.V.B.); (J.F.); (R.U.M.); (M.P.); (A.J.P.)
| | - Jacob Heinz
- Center for Astronomy and Astrophysics, Technische Universität Berlin, 10623 Berlin, Germany; (F.L.A.); (J.H.); (Y.H.); (J.S.)
| | - Yunha Hwang
- Center for Astronomy and Astrophysics, Technische Universität Berlin, 10623 Berlin, Germany; (F.L.A.); (J.H.); (Y.H.); (J.S.)
| | - Samuel P. Kounaves
- Department of Chemistry, Tufts University, Boston, MA 02155, USA;
- Department of Earth Science & Engineering, Imperial College London, London SW7 2AZ, UK
| | - Kai Mangelsdorf
- GFZ German Research Centre for Geosciences, Section Organic Geochemistry, 14473 Potsdam, Germany;
| | - Rainer U. Meckenstock
- Environmental Microbiology and Biotechnology, Department of Chemistry, University of Duisburg-Essen, 45141 Essen, Germany; (T.L.V.B.); (J.F.); (R.U.M.); (M.P.); (A.J.P.)
| | - Mark Pannekens
- Environmental Microbiology and Biotechnology, Department of Chemistry, University of Duisburg-Essen, 45141 Essen, Germany; (T.L.V.B.); (J.F.); (R.U.M.); (M.P.); (A.J.P.)
| | - Alexander J. Probst
- Environmental Microbiology and Biotechnology, Department of Chemistry, University of Duisburg-Essen, 45141 Essen, Germany; (T.L.V.B.); (J.F.); (R.U.M.); (M.P.); (A.J.P.)
| | - Johan S. Sáenz
- Research Unit for Comparative Microbiome Analysis, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany; (J.S.S.); (M.S.)
| | - Janosch Schirmack
- Center for Astronomy and Astrophysics, Technische Universität Berlin, 10623 Berlin, Germany; (F.L.A.); (J.H.); (Y.H.); (J.S.)
| | - Michael Schloter
- Research Unit for Comparative Microbiome Analysis, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany; (J.S.S.); (M.S.)
| | - Philippe Schmitt-Kopplin
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany; (P.-S.K.); (J.U.)
| | - Beate Schneider
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany; (D.L.); (B.S.)
- Federal Institute for Materials Research and Testing (BAM), 12205 Berlin, Germany
| | - Jenny Uhl
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany; (P.-S.K.); (J.U.)
| | - Gisle Vestergaard
- Department of Health Technology, Technical University of Denmark, 2800 Lyngby, Denmark;
| | - Bernardita Valenzuela
- Laboratorio de Microorganismos Extremófilos, Instituto Antofagasta, Universidad de Antofagasta, Av. Angamos 601, Antofagasta 1240000, Chile; (B.V.); (P.Z.)
| | - Pedro Zamorano
- Laboratorio de Microorganismos Extremófilos, Instituto Antofagasta, Universidad de Antofagasta, Av. Angamos 601, Antofagasta 1240000, Chile; (B.V.); (P.Z.)
| | - Dirk Wagner
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany; (D.L.); (B.S.)
- Institute of Geosciences, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
- Correspondence: (D.S.-M.); (D.W.); Tel.: +49-(30)-314-23736 (D.S.-M.); +49-(331)-288-28800 (D.W.)
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14
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George SF, Fierer N, Levy JS, Adams B. Antarctic Water Tracks: Microbial Community Responses to Variation in Soil Moisture, pH, and Salinity. Front Microbiol 2021; 12:616730. [PMID: 33584618 PMCID: PMC7873294 DOI: 10.3389/fmicb.2021.616730] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 01/04/2021] [Indexed: 11/19/2022] Open
Abstract
Ice-free soils in the McMurdo Dry Valleys select for taxa able to cope with challenging environmental conditions, including extreme chemical water activity gradients, freeze-thaw cycling, desiccation, and solar radiation regimes. The low biotic complexity of Dry Valley soils makes them well suited to investigate environmental and spatial influences on bacterial community structure. Water tracks are annually wetted habitats in the cold-arid soils of Antarctica that form briefly each summer with moisture sourced from snow melt, ground ice thaw, and atmospheric deposition via deliquescence and vapor flow into brines. Compared to neighboring arid soils, water tracks are highly saline and relatively moist habitats. They represent a considerable area (∼5–10 km2) of the Dry Valley terrestrial ecosystem, an area that is expected to increase with ongoing climate change. The goal of this study was to determine how variation in the environmental conditions of water tracks influences the composition and diversity of microbial communities. We found significant differences in microbial community composition between on- and off-water track samples, and across two distinct locations. Of the tested environmental variables, soil salinity was the best predictor of community composition, with members of the Bacteroidetes phylum being relatively more abundant at higher salinities and the Actinobacteria phylum showing the opposite pattern. There was also a significant, inverse relationship between salinity and bacterial diversity. Our results suggest water track formation significantly alters dry soil microbial communities, likely influencing subsequent ecosystem functioning. We highlight how Dry Valley water tracks could be a useful model system for understanding the potential habitability of transiently wetted environments found on the surface of Mars.
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Affiliation(s)
- Scott F George
- Department of Biology, Brigham Young University, Provo, UT, United States
| | - Noah Fierer
- Department of Ecology and Evolutionary Biology and Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, United States
| | - Joseph S Levy
- Department of Geology, Colgate University, Hamilton, NY, United States
| | - Byron Adams
- Department of Biology, Brigham Young University, Provo, UT, United States.,Monte L. Bean Museum, Brigham Young University, Provo, UT, United States
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15
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Cheptsov VS, Belov AA, Vorobyova EA, Pavlov AK, Lomasov VN. Effects of Radiation Intensity, Mineral Matrix, and Pre-Irradiation on the Bacterial Resistance to Gamma Irradiation under Low Temperature Conditions. Microorganisms 2021; 9:198. [PMID: 33477915 PMCID: PMC7833375 DOI: 10.3390/microorganisms9010198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 01/13/2021] [Accepted: 01/15/2021] [Indexed: 12/03/2022] Open
Abstract
Ionizing radiation is one of the main factors limiting the survival of microorganisms in extraterrestrial conditions. The survivability of microorganisms under irradiation depends significantly on the conditions, in which the irradiation occurs. In particular, temperature, pressure, oxygen and water concentrations are of great influence. However, the influence of factors such as the radiation intensity (in low-temperature conditions) and the type of mineral matrix, in which microorganisms are located, has been practically unstudied. It has been shown that the radioresistance of bacteria can increase after their exposure to sublethal doses and subsequent repair of damage under favorable conditions, however, such studies are also few and the influence of other factors of extraterrestrial space (temperature, pressure) was not studied in them. The viability of bacteria Arthrobacter polychromogenes, Kocuria rosea and Xanthomonas sp. after irradiation with gamma radiation at a dose of 1 kGy under conditions of low pressure (1 Torr) and low temperature (-50 °C) at different radiation intensities (4 vs. 0.8 kGy/h) with immobilization of bacteria on various mineral matrices (montmorillonite vs. analogue of lunar dust) has been studied. Native, previously non-irradiated strains, and strains that were previously irradiated with gamma radiation and subjected to 10 passages of cultivation on solid media were irradiated. The number of survived cells was determined by culturing on a solid medium. It has been shown that the radioresistance of bacteria depends significantly on the type of mineral matrix, on which they are immobilized, wherein montmorillonite contributes to an increased survivability in comparison with a silicate matrix. Survivability of the studied bacteria was found to increase with decreasing radiation intensity, despite the impossibility of active reparation processes under experimental conditions. Considering the low intensity of radiation on various space objects in comparison with radiobiological experiments, this suggests a longer preservation of the viable microorganisms outside the Earth than is commonly believed. An increase in bacterial radioresistance was revealed even after one cycle of irradiation of the strains and their subsequent cultivation under favourable conditions. This indicates the possibility of hypothetical microorganisms on Mars increasing their radioresistance.
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Affiliation(s)
- Vladimir S. Cheptsov
- Soil Science Faculty, Lomonosov Moscow State University, Leninskie Gory, 1, 12, 119234 Moscow, Russia; (A.A.B.); (E.A.V.)
- Space Research Institute, Russian Academy of Sciences, Profsoyuznaya str., 84/32, 117997 Moscow, Russia
- Network of Researchers on the Chemical Evolution of Life, Leeds LS7 3RB, UK
| | - Andrey A. Belov
- Soil Science Faculty, Lomonosov Moscow State University, Leninskie Gory, 1, 12, 119234 Moscow, Russia; (A.A.B.); (E.A.V.)
- Network of Researchers on the Chemical Evolution of Life, Leeds LS7 3RB, UK
| | - Elena A. Vorobyova
- Soil Science Faculty, Lomonosov Moscow State University, Leninskie Gory, 1, 12, 119234 Moscow, Russia; (A.A.B.); (E.A.V.)
- Network of Researchers on the Chemical Evolution of Life, Leeds LS7 3RB, UK
| | - Anatoli K. Pavlov
- Ioffe Physical-Technical Institute of the Russian Academy of Sciences, Polytechnicheskaya Street, 26, 194021 Saint-Petersburg, Russia;
| | - Vladimir N. Lomasov
- STC “Nuclear Physics”, Peter the Great St. Petersburg State Polytechnic University, Polytechnicheskaya Street, 29, 195251 Saint-Petersburg, Russia;
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16
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Osinski G, Cockell C, Pontefract A, Sapers H. The Role of Meteorite Impacts in the Origin of Life. ASTROBIOLOGY 2020; 20:1121-1149. [PMID: 32876492 PMCID: PMC7499892 DOI: 10.1089/ast.2019.2203] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The conditions, timing, and setting for the origin of life on Earth and whether life exists elsewhere in our solar system and beyond represent some of the most fundamental scientific questions of our time. Although the bombardment of planets and satellites by asteroids and comets has long been viewed as a destructive process that would have presented a barrier to the emergence of life and frustrated or extinguished life, we provide a comprehensive synthesis of data and observations on the beneficial role of impacts in a wide range of prebiotic and biological processes. In the context of previously proposed environments for the origin of life on Earth, we discuss how meteorite impacts can generate both subaerial and submarine hydrothermal vents, abundant hydrothermal-sedimentary settings, and impact analogues for volcanic pumice rafts and splash pools. Impact events can also deliver and/or generate many of the necessary chemical ingredients for life and catalytic substrates such as clays as well. The role that impact cratering plays in fracturing planetary crusts and its effects on deep subsurface habitats for life are also discussed. In summary, we propose that meteorite impact events are a fundamental geobiological process in planetary evolution that played an important role in the origin of life on Earth. We conclude with the recommendation that impact craters should be considered prime sites in the search for evidence of past life on Mars. Furthermore, unlike other geological processes such as volcanism or plate tectonics, impact cratering is ubiquitous on planetary bodies throughout the Universe and is independent of size, composition, and distance from the host star. Impact events thus provide a mechanism with the potential to generate habitable planets, moons, and asteroids throughout the Solar System and beyond.
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Affiliation(s)
- G.R. Osinski
- Institute for Earth and Space Exploration, University of Western Ontario, London, Canada
- Department of Earth Sciences, University of Western Ontario, London, Canada
- Address correspondence to: Dr. Gordon Osinski, Department of Earth Sciences, 1151 Richmond Street, University of Western Ontario, London ON, N6A 5B7, Canada
| | - C.S. Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - A. Pontefract
- Department of Biology, Georgetown University, Washington, DC, USA
| | - H.M. Sapers
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
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17
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Carrier B, Beaty D, Meyer M, Blank J, Chou L, DasSarma S, Des Marais D, Eigenbrode J, Grefenstette N, Lanza N, Schuerger A, Schwendner P, Smith H, Stoker C, Tarnas J, Webster K, Bakermans C, Baxter B, Bell M, Benner S, Bolivar Torres H, Boston P, Bruner R, Clark B, DasSarma P, Engelhart A, Gallegos Z, Garvin Z, Gasda P, Green J, Harris R, Hoffman M, Kieft T, Koeppel A, Lee P, Li X, Lynch K, Mackelprang R, Mahaffy P, Matthies L, Nellessen M, Newsom H, Northup D, O'Connor B, Perl S, Quinn R, Rowe L, Sauterey B, Schneegurt M, Schulze-Makuch D, Scuderi L, Spilde M, Stamenković V, Torres Celis J, Viola D, Wade B, Walker C, Wiens R, Williams A, Williams J, Xu J. Mars Extant Life: What's Next? Conference Report. ASTROBIOLOGY 2020; 20:785-814. [PMID: 32466662 PMCID: PMC7307687 DOI: 10.1089/ast.2020.2237] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 03/24/2020] [Indexed: 05/19/2023]
Abstract
On November 5-8, 2019, the "Mars Extant Life: What's Next?" conference was convened in Carlsbad, New Mexico. The conference gathered a community of actively publishing experts in disciplines related to habitability and astrobiology. Primary conclusions are as follows: A significant subset of conference attendees concluded that there is a realistic possibility that Mars hosts indigenous microbial life. A powerful theme that permeated the conference is that the key to the search for martian extant life lies in identifying and exploring refugia ("oases"), where conditions are either permanently or episodically significantly more hospitable than average. Based on our existing knowledge of Mars, conference participants highlighted four potential martian refugium (not listed in priority order): Caves, Deep Subsurface, Ices, and Salts. The conference group did not attempt to reach a consensus prioritization of these candidate environments, but instead felt that a defensible prioritization would require a future competitive process. Within the context of these candidate environments, we identified a variety of geological search strategies that could narrow the search space. Additionally, we summarized a number of measurement techniques that could be used to detect evidence of extant life (if present). Again, it was not within the scope of the conference to prioritize these measurement techniques-that is best left for the competitive process. We specifically note that the number and sensitivity of detection methods that could be implemented if samples were returned to Earth greatly exceed the methodologies that could be used at Mars. Finally, important lessons to guide extant life search processes can be derived both from experiments carried out in terrestrial laboratories and analog field sites and from theoretical modeling.
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Affiliation(s)
- B.L. Carrier
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - D.W. Beaty
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | | | - J.G. Blank
- NASA Ames Research Center, Moffett Field, California, USA
- Blue Marble Space Institute of Science, Seattle, Washington, USA
| | - L. Chou
- Georgetown University, Washington, DC, USA
- NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - S. DasSarma
- Department of Microbiology and Immunology, Institute of Marine and Environmental Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | | | | | - N.L. Lanza
- Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - A.C. Schuerger
- University of Florida/Space Life Sciences Laboratory, Kennedy Space Center, Florida, USA
| | - P. Schwendner
- University of Florida/Space Life Sciences Laboratory, Kennedy Space Center, Florida, USA
| | - H.D. Smith
- NASA Ames Research Center, Moffett Field, California, USA
| | - C.R. Stoker
- NASA Ames Research Center, Moffett Field, California, USA
| | - J.D. Tarnas
- Brown University, Providence, Rhode Island, USA
| | - K.D. Webster
- Planetary Science Institute, Tucson, Arizona, USA
| | - C. Bakermans
- Pennsylvania State University, Altoona, Pennsylvania, USA
| | - B.K. Baxter
- Westminster College, Salt Lake City, Utah, USA
| | - M.S. Bell
- NASA Johnson Space Center, Houston, Texas, USA
| | - S.A. Benner
- Foundation for Applied Molecular Evolution, Alachua, Florida, USA
| | - H.H. Bolivar Torres
- Universidad Nacional Autonoma de Mexico, Coyoacan, Distrito Federal Mexico, Mexico
| | - P.J. Boston
- NASA Astrobiology Institute, NASA Ames Research Center, Moffett Field, California, USA
| | - R. Bruner
- Denver Museum of Nature and Science, Denver, Colorado, USA
| | - B.C. Clark
- Space Science Institute, Littleton, Colorado, USA
| | - P. DasSarma
- Department of Microbiology and Immunology, Institute of Marine and Environmental Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | - Z.E. Gallegos
- University of New Mexico, Albuquerque, New Mexico, USA
| | - Z.K. Garvin
- Princeton University, Princeton, New Jersey, USA
| | - P.J. Gasda
- Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - J.H. Green
- Texas Tech University, Lubbock, Texas, USA
| | - R.L. Harris
- Princeton University, Princeton, New Jersey, USA
| | - M.E. Hoffman
- University of New Mexico, Albuquerque, New Mexico, USA
| | - T. Kieft
- New Mexico Institute of Mining and Technology, Socorro, New Mexico, USA
| | | | - P.A. Lee
- College of Charleston, Charleston, South Carolina, USA
| | - X. Li
- University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - K.L. Lynch
- Lunar and Planetary Institute/USRA, Houston, Texas, USA
| | - R. Mackelprang
- California State University Northridge, Northridge, California, USA
| | - P.R. Mahaffy
- NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - L.H. Matthies
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | | | - H.E. Newsom
- University of New Mexico, Albuquerque, New Mexico, USA
| | - D.E. Northup
- University of New Mexico, Albuquerque, New Mexico, USA
| | | | - S.M. Perl
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - R.C. Quinn
- NASA Ames Research Center, Moffett Field, California, USA
| | - L.A. Rowe
- Valparaiso University, Valparaiso, Indiana, USA
| | | | | | | | - L.A. Scuderi
- University of New Mexico, Albuquerque, New Mexico, USA
| | - M.N. Spilde
- University of New Mexico, Albuquerque, New Mexico, USA
| | - V. Stamenković
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - J.A. Torres Celis
- Universidad Nacional Autonoma de Mexico, Coyoacan, Distrito Federal Mexico, Mexico
| | - D. Viola
- NASA Ames Research Center, Moffett Field, California, USA
| | - B.D. Wade
- Michigan State University, East Lansing, Michigan, USA
| | - C.J. Walker
- Delaware State University, Dover, Delaware, USA
| | - R.C. Wiens
- Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | | | - J.M. Williams
- University of New Mexico, Albuquerque, New Mexico, USA
| | - J. Xu
- University of Texas, El Paso, Texas, USA
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A New Record for Microbial Perchlorate Tolerance: Fungal Growth in NaClO 4 Brines and its Implications for Putative Life on Mars. Life (Basel) 2020; 10:life10050053. [PMID: 32353964 PMCID: PMC7281446 DOI: 10.3390/life10050053] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 04/21/2020] [Accepted: 04/24/2020] [Indexed: 11/21/2022] Open
Abstract
The habitability of Mars is strongly dependent on the availability of liquid water, which is essential for life as we know it. One of the few places where liquid water might be found on Mars is in liquid perchlorate brines that could form via deliquescence. As these concentrated perchlorate salt solutions do not occur on Earth as natural environments, it is necessary to investigate in lab experiments the potential of these brines to serve as a microbial habitat. Here, we report on the sodium perchlorate (NaClO4) tolerances for the halotolerant yeast Debaryomyces hansenii and the filamentous fungus Purpureocillium lilacinum. Microbial growth was determined visually, microscopically and via counting colony forming units (CFU). With the observed growth of D. hansenii in liquid growth medium containing 2.4 M NaClO4, we found by far the highest microbial perchlorate tolerance reported to date, more than twice as high as the record reported prior (for the bacterium Planococcus halocryophilus). It is plausible to assume that putative Martian microbes could adapt to even higher perchlorate concentrations due to their long exposure to these environments occurring naturally on Mars, which also increases the likelihood of microbial life thriving in the Martian brines.
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Heinz J, Waajen AC, Airo A, Alibrandi A, Schirmack J, Schulze-Makuch D. Bacterial Growth in Chloride and Perchlorate Brines: Halotolerances and Salt Stress Responses of Planococcus halocryophilus. ASTROBIOLOGY 2019; 19:1377-1387. [PMID: 31386567 PMCID: PMC6818489 DOI: 10.1089/ast.2019.2069] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 06/26/2019] [Indexed: 06/10/2023]
Abstract
Extraterrestrial environments encompass physicochemical conditions and habitats that are unknown on Earth, such as perchlorate-rich brines that can be at least temporarily stable on the martian surface. To better understand the potential for life in these cold briny environments, we determined the maximum salt concentrations suitable for growth (MSCg) of six different chloride and perchlorate salts at 25°C and 4°C for the extremotolerant cold- and salt-adapted bacterial strain Planococcus halocryophilus. Growth was measured through colony-forming unit (CFU) counts, while cellular and colonial phenotypic stress responses were observed through visible light, fluorescence, and scanning electron microscopy. Our data show the following: (1) The tolerance to high salt concentrations can be increased through a stepwise inoculation toward higher concentrations. (2) Ion-specific factors are more relevant for the growth limitation of P. halocryophilus in saline solutions than single physicochemical parameters like ionic strength or water activity. (3) P. halocryophilus shows the highest microbial sodium perchlorate tolerance described so far. However, (4) MSCg values are higher for all chlorides compared to perchlorates. (5) The MSCg for calcium chloride was increased by lowering the temperature from 25°C to 4°C, while sodium- and magnesium-containing salts can be tolerated at 25°C to higher concentrations than at 4°C. (6) Depending on salt type and concentration, P. halocryophilus cells show distinct phenotypic stress responses such as novel types of colony morphology on agar plates and biofilm-like cell clustering, encrustation, and development of intercellular nanofilaments. This study, taken in context with previous work on the survival of extremophiles in Mars-like environments, suggests that high-concentrated perchlorate brines on Mars might not be habitable to any present organism on Earth, but extremophilic microorganisms might be able to evolve thriving in such environments.
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Affiliation(s)
- Jacob Heinz
- Center of Astronomy and Astrophysics, Astrobiology Research Group, Technical University of Berlin, Berlin, Germany
| | - Annemiek C. Waajen
- Center of Astronomy and Astrophysics, Astrobiology Research Group, Technical University of Berlin, Berlin, Germany
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Alessandro Airo
- Center of Astronomy and Astrophysics, Astrobiology Research Group, Technical University of Berlin, Berlin, Germany
| | - Armando Alibrandi
- Center of Astronomy and Astrophysics, Astrobiology Research Group, Technical University of Berlin, Berlin, Germany
| | - Janosch Schirmack
- Center of Astronomy and Astrophysics, Astrobiology Research Group, Technical University of Berlin, Berlin, Germany
| | - Dirk Schulze-Makuch
- Center of Astronomy and Astrophysics, Astrobiology Research Group, Technical University of Berlin, Berlin, Germany
- School of the Environment, Washington State University, Pullman, Washington, USA
- GFZ German Center for Geoscience, Section Geomicrobiology, Potsdam, Germany
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Department of Experimental Limnology, Stechlin, Germany
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20
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Contador CA, Veas-Castillo L, Tapia E, Antipán M, Miranda N, Ruiz-Tagle B, García-Araya J, Andrews BA, Marin M, Dorador C, Asenjo JA. Atacama Database: a platform of the microbiome of the Atacama Desert. Antonie van Leeuwenhoek 2019; 113:185-195. [PMID: 31535335 DOI: 10.1007/s10482-019-01328-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 09/07/2019] [Indexed: 11/30/2022]
Abstract
The Atacama Desert is one of the oldest and driest places on Earth. In the last decade, microbial richness and diversity has been acknowledged as an important biological resource of this region. Owing to the value of the microbial diversity apparent in potential biotechnology applications and conservation purposes, it is necessary to catalogue these microbial communities to promote research activities and help to preserve the wide range of ecological niches of the Atacama region. A prototype Atacama Database has been designed and it provides a description of the rich microbial diversity of the Atacama Desert, and helps to visualise available literature resources. Data has been collected, curated, and organised into several categories to generate a single record for each organism in the database that covers classification, isolation metadata, morphology, physiology, genome and metabolism information. The current version of Atacama Database contains 2302 microorganisms and includes cultured and uncultured organisms retrieved from different environments within the desert between 1984 and 2016. These organisms are distributed in bacterial, archaeal or eukaryotic domains, along with those that are unclassified taxonomically. The initial prototype of the Atacama Database includes a basic search and taxonomic and advanced search tools to allow identification and comparison of microbial populations, and space distribution within this biome. A geolocation search was implemented to visualise the microbial diversity of the ecological niches defined by sectors and extract general information of the sampling sites. This effort will aid understanding of the microbial ecology of the desert, microbial population dynamics, seasonal behaviour, impact of climate change over time, and reveal further biotechnological applications of these microorganisms. The Atacama Database is freely available at: https://www.atacamadb.cl.
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Affiliation(s)
- Carolina A Contador
- Centre for Biotechnology and Bioengineering (CeBiB), Department of Chemical Engineering, Biotechnology and Materials, University of Chile, Beauchef 851, 8370456, Santiago, Chile.
| | - Luis Veas-Castillo
- Centre for Biotechnology and Bioengineering (CeBiB), Departamento de Ingeniería Informática (DIINF), Universidad de Santiago de Chile, Santiago, Chile
| | - Emilio Tapia
- Centre for Biotechnology and Bioengineering (CeBiB), Departamento de Ingeniería Informática (DIINF), Universidad de Santiago de Chile, Santiago, Chile
| | - Marcela Antipán
- Centre for Biotechnology and Bioengineering (CeBiB), Department of Chemical Engineering, Biotechnology and Materials, University of Chile, Beauchef 851, 8370456, Santiago, Chile
| | - Noemi Miranda
- Centre for Biotechnology and Bioengineering (CeBiB), Department of Chemical Engineering, Biotechnology and Materials, University of Chile, Beauchef 851, 8370456, Santiago, Chile
| | - Benjamín Ruiz-Tagle
- Centre for Biotechnology and Bioengineering (CeBiB), Departamento de Ingeniería Informática (DIINF), Universidad de Santiago de Chile, Santiago, Chile
| | - Jonathan García-Araya
- Centre for Biotechnology and Bioengineering (CeBiB), Laboratorio de Complejidad Microbiana y Ecología Funcional, Instituto Antofagasta & Departamento de Biotecnología, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Antofagasta, Chile
| | - Barbara A Andrews
- Centre for Biotechnology and Bioengineering (CeBiB), Department of Chemical Engineering, Biotechnology and Materials, University of Chile, Beauchef 851, 8370456, Santiago, Chile
| | - Mauricio Marin
- Centre for Biotechnology and Bioengineering (CeBiB), Departamento de Ingeniería Informática (DIINF), Universidad de Santiago de Chile, Santiago, Chile
| | - Cristina Dorador
- Centre for Biotechnology and Bioengineering (CeBiB), Laboratorio de Complejidad Microbiana y Ecología Funcional, Instituto Antofagasta & Departamento de Biotecnología, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Antofagasta, Chile
| | - Juan A Asenjo
- Centre for Biotechnology and Bioengineering (CeBiB), Department of Chemical Engineering, Biotechnology and Materials, University of Chile, Beauchef 851, 8370456, Santiago, Chile
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21
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Montgomery W, Jaramillo EA, Royle SH, Kounaves SP, Schulze-Makuch D, Sephton MA. Effects of Oxygen-Containing Salts on the Detection of Organic Biomarkers on Mars and in Terrestrial Analog Soils. ASTROBIOLOGY 2019; 19:711-721. [PMID: 31062993 DOI: 10.1089/ast.2018.1888] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The detection of chlorinated hydrocarbons by Curiosity on Mars has been attributed to the presence of unidentified indigenous organic matter. Similarly, oxychlorines on Earth have been proposed to be responsible for the apparent lack of organics in the Atacama Desert. The presence of perchlorate (ClO4-) poses a unique challenge to the measurement of organic matter due to the oxidizing power of oxychlorines during commonly used pyrolysis-gas chromatography-mass spectrometry (py-GC-MS) methods. Here, we show that perchlorates and other oxyanion salts inhibit the detection of organic compounds but that removing these problematic species prior to pyrolysis by using an optimal sample extraction duration and suitable ratios of water to sample mass enables analysis. We have characterized leached and unleached samples containing perchlorates from the Atacama Desert and have found that after leaching, the py-GC-MS chromatograms of the dried mineral residues show identifiable biomarkers associated with indigenous cyanobacteria. Samples which were pyrolyzed without leaching showed no detectable organic matter other than background siloxane and very weak or no trace of detectable polychlorinated benzenes. Dried sample residues remaining after leaching, the mineral matrix and water-insoluble organic matter, showed a strong organic response in all cases when analyzed by py-GC-MS. These residues are most likely the product of the pyrolysis of water-insoluble organics originally present in the samples. In addition, our results imply that previous soil analyses which contained high levels of oxyanions and concluded that organics were either not present or were present at extremely low levels should be reexamined.
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Affiliation(s)
- Wren Montgomery
- 1 Department of Earth Science and Engineering, Imperial College London, London, UK
| | | | - Samuel H Royle
- 1 Department of Earth Science and Engineering, Imperial College London, London, UK
| | - Samuel P Kounaves
- 1 Department of Earth Science and Engineering, Imperial College London, London, UK
- 2 Department of Chemistry, Tufts University, Medford, Massachusetts, USA
| | - Dirk Schulze-Makuch
- 3 Astrobiology Group, Center of Astronomy and Astrophysics, Technical University of Berlin, Berlin, Germany
| | - Mark A Sephton
- 1 Department of Earth Science and Engineering, Imperial College London, London, UK
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22
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Stress-Tolerance and Taxonomy of Culturable Bacterial Communities Isolated from a Central Mojave Desert Soil Sample. GEOSCIENCES 2019. [DOI: 10.3390/geosciences9040166] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The arid Mojave Desert is one of the most significant terrestrial analogue objects for astrobiological research due to its genesis, mineralogy, and climate. However, the knowledge of culturable bacterial communities found in this extreme ecotope’s soil is yet insufficient. Therefore, our research has been aimed to fulfil this lack of knowledge and improve the understanding of functioning of edaphic bacterial communities of the Central Mojave Desert soil. We characterized aerobic heterotrophic soil bacterial communities of the central region of the Mojave Desert. A high total number of prokaryotic cells and a high proportion of culturable forms in the soil studied were observed. Prevalence of Actinobacteria, Proteobacteria, and Firmicutes was discovered. The dominance of pigmented strains in culturable communities and high proportion of thermotolerant and pH-tolerant bacteria were detected. Resistance to a number of salts, including the ones found in Martian regolith, as well as antibiotic resistance, were also estimated.
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23
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Heinz J, Schirmack J, Airo A, Kounaves SP, Schulze-Makuch D. Enhanced Microbial Survivability in Subzero Brines. ASTROBIOLOGY 2018; 18:1171-1180. [PMID: 29664686 PMCID: PMC6150940 DOI: 10.1089/ast.2017.1805] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 03/08/2018] [Indexed: 05/09/2023]
Abstract
It is well known that dissolved salts can significantly lower the freezing point of water and thus extend habitability to subzero conditions. However, most investigations thus far have focused on sodium chloride as a solute. In this study, we report on the survivability of the bacterial strain Planococcus halocryophilus in sodium, magnesium, and calcium chloride or perchlorate solutions at temperatures ranging from +25°C to -30°C. In addition, we determined the survival rates of P. halocryophilus when subjected to multiple freeze/thaw cycles. We found that cells suspended in chloride-containing samples have markedly increased survival rates compared with those in perchlorate-containing samples. In both cases, the survival rates increase with lower temperatures; however, this effect is more pronounced in chloride-containing samples. Furthermore, we found that higher salt concentrations increase survival rates when cells are subjected to freeze/thaw cycles. Our findings have important implications not only for the habitability of cold environments on Earth but also for extraterrestrial environments such as that of Mars, where cold brines might exist in the subsurface and perhaps even appear temporarily at the surface such as at recurring slope lineae.
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Affiliation(s)
- Jacob Heinz
- Center of Astronomy and Astrophysics, Technical University of Berlin, Berlin, Germany
| | - Janosch Schirmack
- Center of Astronomy and Astrophysics, Technical University of Berlin, Berlin, Germany
| | - Alessandro Airo
- Center of Astronomy and Astrophysics, Technical University of Berlin, Berlin, Germany
| | - Samuel P. Kounaves
- Department of Chemistry, Tufts University, Medford, Massachusetts
- Department of Earth Science and Engineering, Imperial College London, London, United Kingdom
| | - Dirk Schulze-Makuch
- Center of Astronomy and Astrophysics, Technical University of Berlin, Berlin, Germany
- School of the Environment, Washington State University, Pullman, Washington
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24
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Wilhelm MB, Davila AF, Parenteau MN, Jahnke LL, Abate M, Cooper G, Kelly ET, Parro García V, Villadangos MG, Blanco Y, Glass B, Wray JJ, Eigenbrode JL, Summons RE, Warren-Rhodes K. Constraints on the Metabolic Activity of Microorganisms in Atacama Surface Soils Inferred from Refractory Biomarkers: Implications for Martian Habitability and Biomarker Detection. ASTROBIOLOGY 2018; 18:955-966. [PMID: 30035640 DOI: 10.1089/ast.2017.1705] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Dryness is one of the main environmental challenges to microbial survival. Understanding the threshold of microbial tolerance to extreme dryness is relevant to better constrain the environmental limits of life on Earth and critically evaluate long-term habitability models of Mars. Biomolecular proxies for microbial adaptation and growth were measured in Mars-like hyperarid surface soils in the Atacama Desert that experience only a few millimeters of precipitation per decade, and in biologically active soils a few hundred kilometers away that experience two- to fivefold more precipitation. Diversity and abundance of lipids and other biomolecules decreased with increasing dryness. Cyclopropane fatty acids (CFAs), which are indicative of adaptive response to environmental stress and growth in bacteria, were only detected in the wetter surface soils. The ratio of trans to cis isomers of an unsaturated fatty acid, another bacterial stress indicator, decreased with increasingly dry conditions. Aspartic acid racemization ratios increased from 0.01 in the wetter soils to 0.1 in the driest soils, which is indicative of racemization rates comparable to de novo biosynthesis over long timescales (∼10,000 years). The content and integrity of stress proteins profiled by immunoassays were additional indicators that biomass in the driest soils is not recycled at significant levels. Together, our results point to minimal or no in situ microbial growth in the driest surface soils of the Atacama, and any metabolic activity is likely to be basal for cellular repair and maintenance only. Our data add to a growing body of evidence that the driest Atacama surface soils represent a threshold for long-term habitability (i.e., growth and reproduction). These results place constraints on the potential for extant life on the surface of Mars, which is 100-1000 times drier than the driest regions in the Atacama. Key Words: Atacama Desert-Dryness-Growth-Habitability-Biomarker-Mars. Astrobiology 18, 955-966.
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Affiliation(s)
- Mary Beth Wilhelm
- 1 School of Earth and Atmospheric Sciences, Georgia Institute of Technology , Atlanta, Georgia
- 2 Space Science and Astrobiology Division, NASA Ames Research Center , Moffett Field, California
| | - Alfonso F Davila
- 2 Space Science and Astrobiology Division, NASA Ames Research Center , Moffett Field, California
| | - Mary N Parenteau
- 2 Space Science and Astrobiology Division, NASA Ames Research Center , Moffett Field, California
| | - Linda L Jahnke
- 2 Space Science and Astrobiology Division, NASA Ames Research Center , Moffett Field, California
| | - Mastewal Abate
- 2 Space Science and Astrobiology Division, NASA Ames Research Center , Moffett Field, California
| | - George Cooper
- 2 Space Science and Astrobiology Division, NASA Ames Research Center , Moffett Field, California
| | | | - Victor Parro García
- 4 Departamento Evolución Molecular, Centro de Astrobiologia (INTA-CSIC) , Madrid, Spain
| | - Miriam G Villadangos
- 4 Departamento Evolución Molecular, Centro de Astrobiologia (INTA-CSIC) , Madrid, Spain
| | - Yolanda Blanco
- 4 Departamento Evolución Molecular, Centro de Astrobiologia (INTA-CSIC) , Madrid, Spain
| | - Brian Glass
- 5 Intelligent Systems Division, NASA Ames Research Center , Moffett Field, California
| | - James J Wray
- 1 School of Earth and Atmospheric Sciences, Georgia Institute of Technology , Atlanta, Georgia
| | - Jennifer L Eigenbrode
- 6 Planetary Environments Laboratory, NASA Goddard Space Flight Center , Greenbelt, Maryland
| | - Roger E Summons
- 7 Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology , Cambridge, Massachusetts
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25
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Abstract
It has remained an unresolved question whether microorganisms recovered from the most arid environments on Earth are thriving under such extreme conditions or are just dead or dying vestiges of viable cells fortuitously deposited by atmospheric processes. Based on multiple lines of evidence, we show that indigenous microbial communities are present and temporally active even in the hyperarid soils of the Atacama Desert (Chile). Following extremely rare precipitation events in the driest parts of this desert, where rainfall often occurs only once per decade, we were able to detect episodic incidences of biological activity. Our findings expand the range of hyperarid environments temporarily habitable for terrestrial life, which by extension also applies to other planetary bodies like Mars. Traces of life are nearly ubiquitous on Earth. However, a central unresolved question is whether these traces always indicate an active microbial community or whether, in extreme environments, such as hyperarid deserts, they instead reflect just dormant or dead cells. Although microbial biomass and diversity decrease with increasing aridity in the Atacama Desert, we provide multiple lines of evidence for the presence of an at times metabolically active, microbial community in one of the driest places on Earth. We base this observation on four major lines of evidence: (i) a physico-chemical characterization of the soil habitability after an exceptional rain event, (ii) identified biomolecules indicative of potentially active cells [e.g., presence of ATP, phospholipid fatty acids (PLFAs), metabolites, and enzymatic activity], (iii) measurements of in situ replication rates of genomes of uncultivated bacteria reconstructed from selected samples, and (iv) microbial community patterns specific to soil parameters and depths. We infer that the microbial populations have undergone selection and adaptation in response to their specific soil microenvironment and in particular to the degree of aridity. Collectively, our results highlight that even the hyperarid Atacama Desert can provide a habitable environment for microorganisms that allows them to become metabolically active following an episodic increase in moisture and that once it decreases, so does the activity of the microbiota. These results have implications for the prospect of life on other planets such as Mars, which has transitioned from an earlier wetter environment to today’s extreme hyperaridity.
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26
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Cabrol NA. The Coevolution of Life and Environment on Mars: An Ecosystem Perspective on the Robotic Exploration of Biosignatures. ASTROBIOLOGY 2018; 18:1-27. [PMID: 29252008 PMCID: PMC5779243 DOI: 10.1089/ast.2017.1756] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/27/2017] [Indexed: 05/09/2023]
Abstract
Earth's biological and environmental evolution are intertwined and inseparable. This coevolution has become a fundamental concept in astrobiology and is key to the search for life beyond our planet. In the case of Mars, whether a coevolution took place is unknown, but analyzing the factors at play shows the uniqueness of each planetary experiment regardless of similarities. Early Earth and early Mars shared traits. However, biological processes on Mars, if any, would have had to proceed within the distinctive context of an irreversible atmospheric collapse, greater climate variability, and specific planetary characteristics. In that, Mars is an important test bed for comparing the effects of a unique set of spatiotemporal changes on an Earth-like, yet different, planet. Many questions remain unanswered about Mars' early environment. Nevertheless, existing data sets provide a foundation for an intellectual framework where notional coevolution models can be explored. In this framework, the focus is shifted from planetary-scale habitability to the prospect of habitats, microbial ecotones, pathways to biological dispersal, biomass repositories, and their meaning for exploration. Critically, as we search for biosignatures, this focus demonstrates the importance of starting to think of early Mars as a biosphere and vigorously integrating an ecosystem approach to landing site selection and exploration. Key Words: Astrobiology-Biosignatures-Coevolution of Earth and life-Mars. Astrobiology 18, 1-27.
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27
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McKay CP, Andersen D, Davila A. Antarctic environments as models of planetary habitats: University Valley as a model for modern Mars and Lake Untersee as a model for Enceladus and ancient Mars. ACTA ACUST UNITED AC 2017. [DOI: 10.1080/2154896x.2017.1383705] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
| | - Dale Andersen
- Carl Sagan Center, SETI Institute, Mountain View, CA, USA
| | - Alfonso Davila
- Space Science Division, NASA Ames Research Center, Mountain View, CA, USA
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28
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Cheng Z, Xiao L, Wang H, Yang H, Li J, Huang T, Xu Y, Ma N. Bacterial and Archaeal Lipids Recovered from Subsurface Evaporites of Dalangtan Playa on the Tibetan Plateau and Their Astrobiological Implications. ASTROBIOLOGY 2017; 17:1112-1122. [PMID: 28926282 DOI: 10.1089/ast.2016.1526] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Qaidam Basin (Tibetan Plateau) is considered an applicable analogue to Mars with regard to sustained extreme aridity and abundant evaporites. To investigate the possibility of the preservation of microbial lipids under these Mars analog conditions, we conducted a mineralogical and organic geochemistry study on samples collected from two Quaternary sections in Dalangtan Playa, northwestern Qaidam Basin, which will enhance our understanding of the potential preservation of molecular biomarkers on Mars. Two sedimentary units were identified along two profiles: one salt unit characterized by a predominance of gypsum and halite, and one detrital unit with a decrease of gypsum and halite and enrichment in siliciclastic minerals. Bacterial fatty acids and archaeal acyclic diether and tetraether membrane lipids were detected, and they varied throughout the sections in concentration and abundance. Bacterial and archaeal biomolecules indicate a dominance of Gram-positive bacteria and halophilic archaea in this hypersaline ecosystem that is similar to those in other hypersaline environments. Furthermore, the abundance of bacterial lipids decreases with the increase of salinity, whereas archaeal lipids showed a reverse trend. The detection of microbial lipids in hypersaline environments would indicate, for example on Mars, a high potential for the detection of microbial biomarkers in evaporites over geological timescales. Key Words: Dalangtan playa-The Qaidam Basin-Subsurface evaporites-Lipid biomarkers-Mars. Astrobiology 17, 1112-1122.
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Affiliation(s)
- Ziye Cheng
- 1 State Key Laboratory of Geological Processes and Mineral Resources, Planetary Science Institute, School of Earth Sciences, China University of Geosciences , Wuhan, China
| | - Long Xiao
- 1 State Key Laboratory of Geological Processes and Mineral Resources, Planetary Science Institute, School of Earth Sciences, China University of Geosciences , Wuhan, China
- 2 Macau University of Science and Technology , Macau, China
| | - Hongmei Wang
- 3 State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences , Wuhan, China
| | - Huan Yang
- 3 State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences , Wuhan, China
| | - Jingjing Li
- 4 State Key Laboratory of Lake Sciences and Environment, Nanjing Institute of Geography and Limnology , Chinese Academy of Sciences, Nanjing, China
| | - Ting Huang
- 1 State Key Laboratory of Geological Processes and Mineral Resources, Planetary Science Institute, School of Earth Sciences, China University of Geosciences , Wuhan, China
| | - Yi Xu
- 2 Macau University of Science and Technology , Macau, China
| | - Nina Ma
- 5 Key Laboratory of Saline Lake Resources and Environments, Chinese Academy of Geological Sciences , Beijing, China
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29
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Schulze-Makuch D, Airo A, Schirmack J. The Adaptability of Life on Earth and the Diversity of Planetary Habitats. Front Microbiol 2017; 8:2011. [PMID: 29085352 PMCID: PMC5650640 DOI: 10.3389/fmicb.2017.02011] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 09/29/2017] [Indexed: 11/13/2022] Open
Abstract
The evolutionary adaptability of life to extreme environments is astounding given that all life on Earth is based on the same fundamental biochemistry. The range of some physicochemical parameters on Earth exceeds the ability of life to adapt, but stays within the limits of life for other parameters. Certain environmental conditions such as low water availability in hyperarid deserts on Earth seem to be close to the limit of biological activity. A much wider range of environmental parameters is observed on planetary bodies within our Solar System such as Mars or Titan, and presumably even larger outside of our Solar System. Here we review the adaptability of life as we know it, especially regarding temperature, pressure, and water activity. We use then this knowledge to outline the range of possible habitable environments for alien planets and moons and distinguish between a variety of planetary environment types. Some of these types are present in our Solar System, others are hypothetical. Our schematic categorization of alien habitats is limited to life as we know it, particularly regarding to the use of solvent (water) and energy source (light and chemical compounds).
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Affiliation(s)
- Dirk Schulze-Makuch
- Astrobiology Group, Center for Astronomy and Astrophysics, Technical University Berlin, Berlin, Germany.,Beyond Center, Arizona State University, Tempe, AZ, United States.,School of the Environment, Washington State University, Pullman, WA, United States
| | - Alessandro Airo
- Astrobiology Group, Center for Astronomy and Astrophysics, Technical University Berlin, Berlin, Germany
| | - Janosch Schirmack
- Astrobiology Group, Center for Astronomy and Astrophysics, Technical University Berlin, Berlin, Germany
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Hays LE, Graham HV, Des Marais DJ, Hausrath EM, Horgan B, McCollom TM, Parenteau MN, Potter-McIntyre SL, Williams AJ, Lynch KL. Biosignature Preservation and Detection in Mars Analog Environments. ASTROBIOLOGY 2017; 17:363-400. [PMID: 28177270 PMCID: PMC5478115 DOI: 10.1089/ast.2016.1627] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
This review of material relevant to the Conference on Biosignature Preservation and Detection in Mars Analog Environments summarizes the meeting materials and discussions and is further expanded upon by detailed references to the published literature. From this diverse source material, there is a detailed discussion on the habitability and biosignature preservation potential of five primary analog environments: hydrothermal spring systems, subaqueous environments, subaerial environments, subsurface environments, and iron-rich systems. Within the context of exploring past habitable environments on Mars, challenges common to all of these key environments are laid out, followed by a focused discussion for each environment regarding challenges to orbital and ground-based observations and sample selection. This leads into a short section on how these challenges could influence our strategies and priorities for the astrobiological exploration of Mars. Finally, a listing of urgent needs and future research highlights key elements such as development of instrumentation as well as continued exploration into how Mars may have evolved differently from Earth and what that might mean for biosignature preservation and detection. Key Words: Biosignature preservation-Biosignature detection-Mars analog environments-Conference report-Astrobiological exploration. Astrobiology 17, 363-400.
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Affiliation(s)
- Lindsay E. Hays
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
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Wilhelm MB, Davila AF, Eigenbrode JL, Parenteau MN, Jahnke LL, Liu XL, Summons RE, Wray JJ, Stamos BN, O’Reilly SS, Williams A. Xeropreservation of functionalized lipid biomarkers in hyperarid soils in the Atacama Desert. ORGANIC GEOCHEMISTRY 2017; 103:97-104. [PMID: 29743757 PMCID: PMC5937136 DOI: 10.1016/j.orggeochem.2016.10.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Our understanding of long-term organic matter preservation comes mostly from studies in aquatic systems. In contrast, taphonomic processes in extremely dry environments are relatively understudied and are poorly understood. We investigated the accumulation and preservation of lipid biomarkers in hyperarid soils in the Yungay region of the Atacama Desert. Lipids from seven soil horizons in a 2.5 m vertical profile were extracted and analyzed using GC-MS and LC-MS. Diagnostic functionalized lipids and geolipids were detected and increased in abundance and diversity with depth. Deeper clay units contain fossil organic matter (radiocarbon dead) that has been protected from rainwater since the onset of hyperaridity. We show that these clay units contain lipids in an excellent state of structural preservation with functional groups and unsaturated bonds in carbon chains. This indicates that minimal degradation of lipids has occurred in these soils since the time of their deposition between >40,000 and 2 million years ago. The exceptional structural preservation of biomarkers is likely due to the long-term hyperaridity that has minimized microbial and enzymatic activity, a taphonomic process we term xeropreservation (i.e. preservation by drying). The degree of biomarker preservation allowed us to reconstruct major changes in ecology in the Yungay region that reflect a shift in hydrological regime from wet to dry since the early Quaternary. Our results suggest that hyperarid environments, which comprise 7.5% of the continental landmass, could represent a rich and relatively unexplored source of paleobiological information on Earth.
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Affiliation(s)
- Mary Beth Wilhelm
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332 USA
- Space Science and Astrobiology Division, NASA Ames Research Center, Moffett Field, CA 94035 USA
- Corresponding author: Telephone: (650) 604-0489;
| | - Alfonso F. Davila
- Space Science and Astrobiology Division, NASA Ames Research Center, Moffett Field, CA 94035 USA
- SETI Institute 189 N Bernardo Ave, Mountain View, CA 94043 USA
| | - Jennifer L. Eigenbrode
- Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 USA
| | - Mary N. Parenteau
- Space Science and Astrobiology Division, NASA Ames Research Center, Moffett Field, CA 94035 USA
| | - Linda L. Jahnke
- Space Science and Astrobiology Division, NASA Ames Research Center, Moffett Field, CA 94035 USA
| | - Xiao-Lei Liu
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02141 USA
| | - Roger E. Summons
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02141 USA
| | - James J. Wray
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332 USA
| | - Brian N. Stamos
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019 USA
| | - Shane S. O’Reilly
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02141 USA
| | - Amy Williams
- Department of Physics, Astronomy, and Geosciences, Towson University, 8000 York Road, Towson, MD 21252 USA
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