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Paris ER, Arandia-Gorostidi N, Klempay B, Bowman JS, Pontefract A, Elbon CE, Glass JB, Ingall ED, Doran PT, Som SM, Schmidt BE, Dekas AE. Single-cell analysis in hypersaline brines predicts a water-activity limit of microbial anabolic activity. SCIENCE ADVANCES 2023; 9:eadj3594. [PMID: 38134283 PMCID: PMC10745694 DOI: 10.1126/sciadv.adj3594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/22/2023] [Indexed: 12/24/2023]
Abstract
Hypersaline brines provide excellent opportunities to study extreme microbial life. Here, we investigated anabolic activity in nearly 6000 individual cells from solar saltern sites with water activities (aw) ranging from 0.982 to 0.409 (seawater to extreme brine). Average anabolic activity decreased exponentially with aw, with nuanced trends evident at the single-cell level: The proportion of active cells remained high (>50%) even after NaCl saturation, and subsets of cells spiked in activity as aw decreased. Intracommunity heterogeneity in activity increased as seawater transitioned to brine, suggesting increased phenotypic heterogeneity with increased physiological stress. No microbial activity was detected in the 0.409-aw brine (an MgCl2-dominated site) despite the presence of cell-like structures. Extrapolating our data, we predict an aw limit for detectable anabolic activity of 0.540, which is beyond the currently accepted limit of life based on cell division. This work demonstrates the utility of single-cell, metabolism-based techniques for detecting active life and expands the potential habitable space on Earth and beyond.
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Affiliation(s)
- Emily R. Paris
- Department of Earth System Science, Stanford University, Stanford, CA 94305, USA
| | | | - Benjamin Klempay
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA 92037, USA
| | - Jeff S. Bowman
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA 92037, USA
| | | | - Claire E. Elbon
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Jennifer B. Glass
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Ellery D. Ingall
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Peter T. Doran
- Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Sanjoy M. Som
- Blue Marble Space Institute of Science, Seattle, WA 98104, USA
| | - Britney E. Schmidt
- Departments of Astronomy and Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Anne E. Dekas
- Department of Earth System Science, Stanford University, Stanford, CA 94305, USA
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2
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Ferreira GW, Samulewski RB, Ivashita FF, Paesano A, Urbano A, Zaia DAM. Did Salts in Seawater Play an Important Role in the Adsorption of Molecules on Minerals in the Prebiotic Earth? The Case of the Adsorption of Thiocyanate onto Forsterite-91. ORIGINS LIFE EVOL B 2023; 53:127-156. [PMID: 37676558 DOI: 10.1007/s11084-023-09640-3] [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: 07/28/2023] [Accepted: 08/09/2023] [Indexed: 09/08/2023]
Abstract
Thiocyanate may have played as important a role as cyanide in the synthesis of several molecules. However, its concentration in the seas of the prebiotic Earth could have been very low. Thiocyanate was dissolved in two different seawaters: a) a composition that comes close to the seawater of the prebiotic Earth (seawater-B, Ca2+ and Cl-) and b) a seawater (seawater-A, Mg2+ and SO42-) that could be related to the seas of Mars and other moons in the solar system. In addition, forsterite-91 was a very common mineral on the prebiotic Earth and Mars. Two important results are reported in this work: 1) thiocyanate adsorbed onto forsterite-91 and 2) the amount of thiocyanate adsorbed, adsorption thermodynamic, and adsorption kinetic depend on the composition of the artificial seawater. For all experiments, the adsorption was thermodynamically favorable (ΔG < 0). The adsorption data fitted well in the Freundlich and Langmuir-Freundlich models. When dissolving thiocyanate in seawater 4.0-A-Gy and seawater 4.0-B-Gy, the adsorption of thiocyanate onto forsterite-91 was ruled by enthalpy and entropy, respectively. As shown by n values, the thiocyanate/foraterite-91 system is heterogeneous. For all kinetic data, the pseudo-first-order model presented the best fit. The constant rate for thiocyanate dissolved in seawater 4.0-A-Gy was twice that compared to thiocyanate dissolved in seawater 4.0-B-Gy or ultrapure-water. The interaction between thiocyanate and Fe2+ of forsterite-91 was with the nitrogen atom of thiocyanate. In the presence of thiocyanate, sulfate interacts with forsterite-91 as an inner-sphere surface complex, and without thiocyanate as an outer-sphere surface complex.
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Affiliation(s)
- Giulio Wilgner Ferreira
- Laboratório de Química Prebiótica-LQP, Departamento de Química, Universidade Estadual de Londrina, CEP 86057-970, Londrina, PR, Brazil
| | - Rafael Block Samulewski
- COLIQ - Coordenação de Licenciatura em Química, Universidade Tecnológica Federal do Paraná UTFPR Campus Apucarana, CEP 86812-460, Apucarana, PR, Brazil.
| | | | - Andrea Paesano
- Departamento de Física-CCE, Universidade Estadual de Maringá, 87020-900, Maringá, PR, Brazil
- Departamento de Física Teórica e Experimental, UFRN, Av. Sen. Salgado Filho, 3000, Lagoa Nova, 59078-970, Natal, RN, Brazil
| | - Alexandre Urbano
- Departamento de Física-CCE, Universidade Estadual de Londrina, CEP 86057-970, Londrina, PR, Brazil
| | - Dimas Augusto Morozin Zaia
- Laboratório de Química Prebiótica-LQP, Departamento de Química, Universidade Estadual de Londrina, CEP 86057-970, Londrina, PR, Brazil.
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Vance SD, Craft KL, Shock E, Schmidt BE, Lunine J, Hand KP, McKinnon WB, Spiers EM, Chivers C, Lawrence JD, Wolfenbarger N, Leonard EJ, Robinson KJ, Styczinski MJ, Persaud DM, Steinbrügge G, Zolotov MY, Quick LC, Scully JEC, Becker TM, Howell SM, Clark RN, Dombard AJ, Glein CR, Mousis O, Sephton MA, Castillo-Rogez J, Nimmo F, McEwen AS, Gudipati MS, Jun I, Jia X, Postberg F, Soderlund KM, Elder CM. Investigating Europa's Habitability with the Europa Clipper. SPACE SCIENCE REVIEWS 2023; 219:81. [PMID: 38046182 PMCID: PMC10687213 DOI: 10.1007/s11214-023-01025-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 11/03/2023] [Indexed: 12/05/2023]
Abstract
The habitability of Europa is a property within a system, which is driven by a multitude of physical and chemical processes and is defined by many interdependent parameters, so that its full characterization requires collaborative investigation. To explore Europa as an integrated system to yield a complete picture of its habitability, the Europa Clipper mission has three primary science objectives: (1) characterize the ice shell and ocean including their heterogeneity, properties, and the nature of surface-ice-ocean exchange; (2) characterize Europa's composition including any non-ice materials on the surface and in the atmosphere, and any carbon-containing compounds; and (3) characterize Europa's geology including surface features and localities of high science interest. The mission will also address several cross-cutting science topics including the search for any current or recent activity in the form of thermal anomalies and plumes, performing geodetic and radiation measurements, and assessing high-resolution, co-located observations at select sites to provide reconnaissance for a potential future landed mission. Synthesizing the mission's science measurements, as well as incorporating remote observations by Earth-based observatories, the James Webb Space Telescope, and other space-based resources, to constrain Europa's habitability, is a complex task and is guided by the mission's Habitability Assessment Board (HAB).
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Affiliation(s)
- Steven D. Vance
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | - Kathleen L. Craft
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD USA
| | - Everett Shock
- School of Earth & Space Exploration and School of Molecular Sciences, Arizona State University, Tempe, AZ USA
| | - Britney E. Schmidt
- Department of Astronomy and Department of Earth & Atmospheric Sciences, Cornell University, Ithaca, NY USA
| | - Jonathan Lunine
- Department of Astronomy and Department of Earth & Atmospheric Sciences, Cornell University, Ithaca, NY USA
| | - Kevin P. Hand
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | - William B. McKinnon
- Department of Earth and Planetary Sciences and McDonnell Center for the Space Sciences, Washington University in St. Louis, Saint Louis, MO USA
| | - Elizabeth M. Spiers
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA USA
| | - Chase Chivers
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA USA
- Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, MA USA
| | - Justin D. Lawrence
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA USA
- Honeybee Robotics, Altadena, CA USA
| | - Natalie Wolfenbarger
- Institute for Geophysics, John A. and Katherine G. Jackson School of Geosciences, University of Texas at Austin, Austin, TX USA
| | - Erin J. Leonard
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | | | | | - Divya M. Persaud
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | - Gregor Steinbrügge
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | - Mikhail Y. Zolotov
- School of Earth & Space Exploration and School of Molecular Sciences, Arizona State University, Tempe, AZ USA
| | | | | | | | - Samuel M. Howell
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | | | - Andrew J. Dombard
- Dept. of Earth and Environmental Sciences, University of Illinois Chicago, Chicago, USA
| | | | - Olivier Mousis
- Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille), Marseille, France
| | - Mark A. Sephton
- Impacts and Astromaterials Research Centre, Department of Earth Science and Engineering, Imperial College London, London, United Kingdom
| | | | - Francis Nimmo
- Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA USA
| | - Alfred S. McEwen
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - Murthy S. Gudipati
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | - Insoo Jun
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
| | - Xianzhe Jia
- Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI USA
| | - Frank Postberg
- Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany
| | - Krista M. Soderlund
- Institute for Geophysics, John A. and Katherine G. Jackson School of Geosciences, University of Texas at Austin, Austin, TX USA
| | - Catherine M. Elder
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA
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4
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Carré L, Gonzalez D, Girard É, Franzetti B. Effects of chaotropic salts on global proteome stability in halophilic archaea: Implications for life signatures on Mars. Environ Microbiol 2023; 25:2216-2230. [PMID: 37349893 DOI: 10.1111/1462-2920.16451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 05/28/2023] [Indexed: 06/24/2023]
Abstract
Halophilic archaea thriving in hypersaline environments, such as salt lakes, offer models for putative life in extraterrestrial brines such as those found on Mars. However, little is known about the effect of the chaotropic salts that could be found in such brines, such as MgCl2 , CaCl2 and (per)chlorate salts, on complex biological samples like cell lysates which could be expected to be more representative of biomarkers left behind putative extraterrestrial life forms. We used intrinsic fluorescence to study the salt dependence of proteomes extracted from five halophilic strains: Haloarcula marismortui, Halobacterium salinarum, Haloferax mediterranei, Halorubrum sodomense and Haloferax volcanii. These strains were isolated from Earth environments with different salt compositions. Among the five strains that were analysed, H. mediterranei stood out as a results of its high dependency on NaCl for its proteome stabilization. Interestingly, the results showed contrasting denaturation responses of the proteomes to chaotropic salts. In particular, the proteomes of strains that are most dependent or tolerant on MgCl2 for growth exhibited higher tolerance towards chaotropic salts that are abundant in terrestrial and Martian brines. These experiments bridge together global protein properties and environmental adaptation and help guide the search for protein-like biomarkers in extraterrestrial briny environments.
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Affiliation(s)
- Lorenzo Carré
- Université Grenoble Alpes, CNRS, CEA, IBS, Grenoble, France
| | | | - Éric Girard
- Université Grenoble Alpes, CNRS, CEA, IBS, Grenoble, France
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5
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Durán-Viseras A, Sánchez-Porro C, Viver T, Konstantinidis KT, Ventosa A. Discovery of the Streamlined Haloarchaeon Halorutilus salinus, Comprising a New Order Widespread in Hypersaline Environments across the World. mSystems 2023; 8:e0119822. [PMID: 36943059 PMCID: PMC10134839 DOI: 10.1128/msystems.01198-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023] Open
Abstract
The class Halobacteria is one of the most diverse groups within the Euryarchaeota phylum, whose members are ubiquitously distributed in hypersaline environments, where they often constitute the major population. Here, we report the discovery and isolation of a new halophilic archaeon, strain F3-133T exhibiting ≤86.3% 16S rRNA gene identity to any previously cultivated archaeon, and, thus, representing a new order. Analysis of available 16S rRNA gene amplicon and metagenomic data sets showed that the new isolate represents an abundant group in intermediate-to-high salinity ecosystems and is widely distributed across the world. The isolate presents a streamlined genome, which probably accounts for its ecological success in nature and its fastidious growth in culture. The predominant osmoprotection mechanism appears to be the typical salt-in strategy used by other haloarchaea. Furthermore, the genome contains the complete gene set for nucleotide monophosphate degradation pathway through archaeal RuBisCO, being within the first halophilic archaea representatives reported to code this enzyme. Genomic comparisons with previously described representatives of the phylum Euryarchaeota were consistent with the 16S rRNA gene data in supporting that our isolate represents a novel order within the class Halobacteria for which we propose the names Halorutilales ord. nov., Halorutilaceae fam. nov., Halorutilus gen. nov. and Halorutilus salinus sp. nov. IMPORTANCE The discovery of the new halophilic archaeon, Halorutilus salinus, representing a novel order, family, genus, and species within the class Halobacteria and phylum Euryarchaeota clearly enables insights into the microbial dark matter, expanding the current taxonomical knowledge of this group of archaea. The in-depth comparative genomic analysis performed on this new taxon revealed one of the first known examples of an Halobacteria representative coding the archaeal RuBisCO gene and with a streamlined genome, being ecologically successful in nature and explaining its previous non-isolation. Altogether, this research brings light into the understanding of the physiology of the Halobacteria class members, their ecological distribution, and capacity to thrive in hypersaline environments.
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Affiliation(s)
- Ana Durán-Viseras
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, Sevilla, Spain
- School of Civil & Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Cristina Sánchez-Porro
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, Sevilla, Spain
| | - Tomeu Viver
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Mediterranean Institute for Advanced Studies (IMEDEA, CSIC-UIB), Esporles, Spain
| | | | - Antonio Ventosa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, Sevilla, Spain
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6
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Fairén AG, Rodríguez N, Sánchez-García L, Rojas P, Uceda ER, Carrizo D, Amils R, Sanz JL. Ecological successions throughout the desiccation of Tirez lagoon (Spain) as an astrobiological time-analog for wet-to-dry transitions on Mars. Sci Rep 2023; 13:1423. [PMID: 36755119 PMCID: PMC9908944 DOI: 10.1038/s41598-023-28327-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 01/17/2023] [Indexed: 02/10/2023] Open
Abstract
Tirez was a small and seasonal endorheic athalassohaline lagoon that was located in central Spain. In recent years, the lagoon has totally dried out, offering for the first time the opportunity to analyze its desiccation process as a "time-analog" to similar events occurred in paleolakes with varying salinity during the wet-to-dry transition on early Mars. On the martian cratered highlands, an early period of water ponding within enclosed basins evolved to a complete desiccation of the lakes, leading to deposition of evaporitic sequences during the Noachian and into the Late Hesperian. As Tirez also underwent a process of desiccation, here we describe (i) the microbial ecology of Tirez when the lagoon was still active 20 years ago, with prokaryotes adapted to extreme saline conditions; (ii) the composition of the microbial community in the dried lake sediments today, in many case groups that thrive in sediments of extreme environments; and (iii) the molecular and isotopic analysis of the lipid biomarkers that can be recovered from the sediments today. We discuss the implications of these results to better understanding the ecology of possible Martian microbial communities during the wet-to-dry transition at the end of the Hesperian, and how they may inform about research strategies to search for possible biomarkers in Mars after all the water was lost.
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Affiliation(s)
- Alberto G Fairén
- Centro de Astrobiología (CSIC-INTA), 28850, Torrejón de Ardoz, Spain. .,Department of Astronomy, Cornell University, Ithaca, NY, 14853, USA.
| | - Nuria Rodríguez
- Centro de Astrobiología (CSIC-INTA), 28850, Torrejón de Ardoz, Spain.,Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain
| | | | - Patricia Rojas
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain
| | - Esther R Uceda
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain
| | - Daniel Carrizo
- Centro de Astrobiología (CSIC-INTA), 28850, Torrejón de Ardoz, Spain
| | - Ricardo Amils
- Centro de Astrobiología (CSIC-INTA), 28850, Torrejón de Ardoz, Spain.,Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain.,Departamento de Biología Molecular, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain
| | - José L Sanz
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain.
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7
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Macey MC, Ramkissoon NK, Cogliati S, Toubes-Rodrigo M, Stephens BP, Kucukkilic-Stephens E, Schwenzer SP, Pearson VK, Preston LJ, Olsson-Francis K. Habitability and Biosignature Formation in Simulated Martian Aqueous Environments. ASTROBIOLOGY 2023; 23:144-154. [PMID: 36577028 DOI: 10.1089/ast.2021.0197] [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: 06/17/2023]
Abstract
Water present on early Mars is often assumed to have been habitable. In this study, experiments were performed to investigate the habitability of well-defined putative martian fluids and to identify the accompanying potential formation of biosignatures. Simulated martian environments were developed by combining martian fluid and regolith simulants based on the chemistry of the Rocknest sand shadow at Gale Crater. The simulated chemical environment was inoculated with terrestrial anoxic sediment from the Pyefleet mudflats (United Kingdom). These enrichments were cultured for 28 days and subsequently subcultured seven times to ensure that the microbial community was solely grown on the defined, simulated chemistry. The impact of the simulated chemistries on the microbial community was assessed by cell counts and sequencing of 16S rRNA gene profiles. Associated changes to the fluid and precipitate chemistries were established by using ICP-OES, IC, FTIR, and NIR. The fluids were confirmed as habitable, with the enriched microbial community showing a reduction in abundance and diversity over multiple subcultures relating to the selection of specific metabolic groups. The final community comprised sulfate-reducing, acetogenic, and other anaerobic and fermentative bacteria. Geochemical characterization and modeling of the simulant and fluid chemistries identified clear differences between the biotic and abiotic experiments. These differences included the elimination of sulfur owing to the presence of sulfate-reducing bacteria and more general changes in pH associated with actively respiring cells that impacted the mineral assemblages formed. This study confirmed that a system simulating the fluid chemistry of Gale Crater could support a microbial community and that variation in chemistries under biotic and abiotic conditions can be used to inform future life-detection missions.
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Affiliation(s)
- Michael C Macey
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Nisha K Ramkissoon
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Simone Cogliati
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Mario Toubes-Rodrigo
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Ben P Stephens
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Ezgi Kucukkilic-Stephens
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Susanne P Schwenzer
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Victoria K Pearson
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Louisa J Preston
- Mullard Space Science Laboratory, Department of Space and Climate Physics, University College London, London, United Kingdom
| | - Karen Olsson-Francis
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
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8
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Biophysical Manipulation of the Extracellular Environment by Eurotium halophilicum. Pathogens 2022; 11:pathogens11121462. [PMID: 36558795 PMCID: PMC9781259 DOI: 10.3390/pathogens11121462] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 11/25/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022] Open
Abstract
Eurotium halophilicum is psychrotolerant, halophilic, and one of the most-extreme xerophiles in Earth's biosphere. We already know that this ascomycete grows close to 0 °C, at high NaCl, and-under some conditions-down to 0.651 water-activity. However, there is a paucity of information about how it achieves this extreme stress tolerance given the dynamic water regimes of the surface habitats on which it commonly occurs. Here, against the backdrop of global climate change, we investigated the biophysical interactions of E. halophilicum with its extracellular environment using samples taken from the surfaces of library books. The specific aims were to examine its morphology and extracellular environment (using scanning electron microscopy for visualisation and energy-dispersive X-ray spectrometry to identify chemical elements) and investigate interactions with water, ions, and minerals (including analyses of temperature and relative humidity conditions and determinations of salt deliquescence and water activity of extracellular brine). We observed crystals identified as eugsterite (Na4Ca(SO4)3·2H2O) and mirabilite (Na2SO4·10H2O) embedded within extracellular polymeric substances and provide evidence that E. halophilicum uses salt deliquescence to maintain conditions consistent with its water-activity window for growth. In addition, it utilizes a covering of hair-like microfilaments that likely absorb water and maintain a layer of humid air adjacent to the hyphae. We believe that, along with compatible solutes used for osmotic adjustment, these adaptations allow the fungus to maintain hydration in both space and time. We discuss these findings in relation to the conservation of books and other artifacts within the built environment, spoilage of foods and feeds, the ecology of E. halophilicum in natural habitats, and the current episode of climate change.
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9
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Danilova OA, Ianutsevich EA, Bondarenko SA, Antropova AB, Tereshina VM. Membrane Lipids and Osmolytes Composition of Xerohalophilic Fungus Aspergillus penicillioides during Growth on High NaCl and Glycerol Media. Microbiology (Reading) 2022. [DOI: 10.1134/s0026261722601373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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10
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Wolfenbarger NS, Buffo JJ, Soderlund KM, Blankenship DD. Ice Shell Structure and Composition of Ocean Worlds: Insights from Accreted Ice on Earth. ASTROBIOLOGY 2022; 22:937-961. [PMID: 35787145 DOI: 10.1089/ast.2021.0044] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Accreted ice retains and preserves traces of the ocean from which it formed. In this work, we study two classes of accreted ice found on Earth-frazil ice, which forms through crystallization within a supercooled water column, and congelation ice, which forms through directional freezing at an existing interface-and discuss where each might be found in the ice shells of ocean worlds. We focus our study on terrestrial ice formed in low temperature gradient environments (e.g., beneath ice shelves), consistent with conditions expected at the ice-ocean interfaces of Europa and Enceladus, and we highlight the juxtaposition of compositional trends in relation to ice formed in higher temperature gradient environments (e.g., at the ocean surface). Observations from Antarctic sub-ice-shelf congelation ice and marine ice show that the purity of frazil ice can be nearly two orders of magnitude higher than congelation ice formed in the same low temperature gradient environment (∼0.1% vs. ∼10% of the ocean salinity). In addition, where congelation ice can maintain a planar ice-water interface on a microstructural scale, the efficiency of salt rejection is enhanced (∼1% of the ocean salinity) and lattice soluble impurities such as chloride are preferentially incorporated. We conclude that an ice shell that forms by gradual thickening as its interior cools would be composed of congelation ice, whereas frazil ice will accumulate where the ice shell thins on local (rifts and basal fractures) or regional (latitudinal gradients) scales through the operation of an "ice pump."
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Affiliation(s)
| | - Jacob J Buffo
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire, USA
| | - Krista M Soderlund
- Institute for Geophysics, University of Texas at Austin, Austin, Texas, USA
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11
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Buffo JJ, Brown EK, Pontefract A, Schmidt BE, Klempay B, Lawrence J, Bowman J, Grantham M, Glass JB, Plattner T, Chivers C, Doran P. The Bioburden and Ionic Composition of Hypersaline Lake Ices: Novel Habitats on Earth and Their Astrobiological Implications. ASTROBIOLOGY 2022; 22:962-980. [PMID: 35671513 DOI: 10.1089/ast.2021.0078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We present thermophysical, biological, and chemical observations of ice and brine samples from five compositionally diverse hypersaline lakes in British Columbia's interior plateau. Possessing a spectrum of magnesium, sodium, sulfate, carbonate, and chloride salts, these low-temperature high-salinity lakes are analogs for planetary ice-brine environments, including the ice shells of Europa and Enceladus and ice-brine systems on Mars. As such, understanding the thermodynamics and biogeochemistry of these systems can provide insights into the evolution, habitability, and detectability of high-priority astrobiology targets. We show that biomass is typically concentrated in a layer near the base of the ice cover, but that chemical and biological impurities are present throughout the ice. Coupling bioburden, ionic concentration, and seasonal temperature measurements, we demonstrate that impurity entrainment in the ice is directly correlated to ice formation rate and parent fluid composition. We highlight unique phenomena, including brine supercooling, salt hydrate precipitation, and internal brine layers in the ice cover, important processes to be considered for planetary ice-brine environments. These systems can be leveraged to constrain the distribution, longevity, and habitability of low-temperature solar system brines-relevant to interpreting spacecraft data and planning future missions in the lens of both planetary exploration and planetary protection.
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Affiliation(s)
- Jacob J Buffo
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA
| | - Emma K Brown
- School of Earth and Space Exploration, Arizona State University, Pheonix, AZ, USA
| | | | | | | | - Justin Lawrence
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Jeff Bowman
- Scripps Institution of Oceanography, La Jolla, CA, USA
| | - Meg Grantham
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Jennifer B Glass
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Taylor Plattner
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Chase Chivers
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Peter Doran
- Department of Geology and Geophysics, Louisiung State University, Baton Rouge, LA, USA
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12
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Oliver JAW, Kelbrick M, Ramkissoon NK, Dugdale A, Stephens BP, Kucukkilic-Stephens E, Fox-Powell MG, Schwenzer SP, Antunes A, Macey MC. Sulfur Cycling as a Viable Metabolism under Simulated Noachian/Hesperian Chemistries. Life (Basel) 2022; 12:life12040523. [PMID: 35455014 PMCID: PMC9024814 DOI: 10.3390/life12040523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/24/2022] [Accepted: 03/30/2022] [Indexed: 12/17/2022] Open
Abstract
Water present on the surface of early Mars (>3.0 Ga) may have been habitable. Characterising analogue environments and investigating the aspects of their microbiome best suited for growth under simulated martian chemical conditions is key to understanding potential habitability. Experiments were conducted to investigate the viability of microbes from a Mars analogue environment, Colour Peak Springs (Axel Heiberg Island, Canadian High Arctic), under simulated martian chemistries. The fluid was designed to emulate waters thought to be typical of the late Noachian, in combination with regolith simulant material based on two distinct martian geologies. These experiments were performed with a microbial community from Colour Peak Springs sediment. The impact on the microbes was assessed by cell counting and 16S rRNA gene amplicon sequencing. Changes in fluid chemistries were tested using ICP-OES. Both chemistries were shown to be habitable, with growth in both chemistries. Microbial communities exhibited distinct growth dynamics and taxonomic composition, comprised of sulfur-cycling bacteria, represented by either sulfate-reducing or sulfur-oxidising bacteria, and additional heterotrophic halophiles. Our data support the identification of Colour Peak Springs as an analogue for former martian environments, with a specific subsection of the biota able to survive under more accurate proxies for martian chemistries.
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Affiliation(s)
- James A. W. Oliver
- Biology Department, Edge Hill University, Ormskirk L39 4QP, UK; (J.A.W.O.); (M.K.)
| | - Matthew Kelbrick
- Biology Department, Edge Hill University, Ormskirk L39 4QP, UK; (J.A.W.O.); (M.K.)
- Department of Evolution, Ecology and Behaviour, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L69 3GJ, UK
| | - Nisha K. Ramkissoon
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (M.G.F.-P.); (S.P.S.)
| | - Amy Dugdale
- AstrobiologyOU, School of Physical Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK;
- Biology Department, Maynooth University, Maynooth, W23 F2H6 Kildare, Ireland
| | - Ben P. Stephens
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (M.G.F.-P.); (S.P.S.)
| | - Ezgi Kucukkilic-Stephens
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (M.G.F.-P.); (S.P.S.)
| | - Mark G. Fox-Powell
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (M.G.F.-P.); (S.P.S.)
- School of Earth & Environmental Sciences, University of St Andrews, Fife KY16 9AJ, UK
| | - Susanne P. Schwenzer
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (M.G.F.-P.); (S.P.S.)
| | - André Antunes
- State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology (MUST), Macau, China;
- China National Space Administration (CNSA), Macau Center for Space Exploration and Science, Macau, China
| | - Michael C. Macey
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (M.G.F.-P.); (S.P.S.)
- Correspondence:
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13
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Price A, Macey MC, Pearson VK, Schwenzer SP, Ramkissoon NK, Olsson-Francis K. Oligotrophic Growth of Nitrate-Dependent Fe 2+-Oxidising Microorganisms Under Simulated Early Martian Conditions. Front Microbiol 2022; 13:800219. [PMID: 35418959 PMCID: PMC8997339 DOI: 10.3389/fmicb.2022.800219] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 02/24/2022] [Indexed: 11/30/2022] Open
Abstract
Nitrate-dependent Fe2+ oxidation (NDFO) is a microbially mediated process observed in many anaerobic, low-nutrient (oligotrophic) neutral-alkaline environments on Earth, which describes oxidation of Fe2+ to Fe3+ in tandem with microbial nitrate reduction. Evidence suggests that similar environments existed on Mars during the Noachian epoch (4.1-3.7 Ga) and in periodic, localised environments more recently, indicating that NDFO metabolism could have played a role in a potential early martian biosphere. In this paper, three NDFO microorganisms, Acidovorax sp. strain BoFeN1, Pseudogulbenkiania sp. strain 2002 and Paracoccus sp. strain KS1, were assessed for their ability to grow oligotrophically in simulated martian brines and in a minimal medium with olivine as a solid Fe2+ source. These simulant-derived media were developed from modelled fluids based on the geochemistry of Mars sample locations at Rocknest (contemporary Mars soil), Paso Robles (sulphur-rich soil), Haematite Slope (haematite-rich soil) and a Shergottite meteorite (common basalt). The Shergottite medium was able to support growth of all three organisms, while the contemporary Mars medium supported growth of Acidovorax sp. strain BoFeN1 and Pseudogulbenkiania sp. strain 2002; however, growth was not accompanied by significant Fe2+ oxidation. Each of the strains was also able to grow in oligotrophic minimal media with olivine as the sole Fe2+ source. Biomineralised cells of Pseudogulbenkiania sp. strain 2002 were identified on the surface of the olivine, representing a potential biosignature for NDFO microorganisms in martian samples. The results suggest that NDFO microorganisms could have thrived in early martian groundwaters under oligotrophic conditions, depending on the local lithology. This can guide missions in identifying palaeoenvironments of interest for biosignature detection. Indeed, biomineralised cells identified on the olivine surface provide a previously unexplored mechanism for the preservation of morphological biosignatures in the martian geological record.
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Affiliation(s)
- Alex Price
- School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering, and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Michael C. Macey
- School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering, and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Victoria K. Pearson
- School of Physical Sciences, Faculty of Science, Technology, Engineering, and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Susanne P. Schwenzer
- School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering, and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Nisha K. Ramkissoon
- School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering, and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Karen Olsson-Francis
- School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering, and Mathematics, The Open University, Milton Keynes, United Kingdom
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14
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Kelbrick M, Oliver JAW, Ramkissoon NK, Dugdale A, Stephens BP, Kucukkilic-Stephens E, Schwenzer SP, Antunes A, Macey MC. Microbes from Brine Systems with Fluctuating Salinity Can Thrive under Simulated Martian Chemical Conditions. Life (Basel) 2021; 12:life12010012. [PMID: 35054406 PMCID: PMC8781782 DOI: 10.3390/life12010012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/15/2021] [Accepted: 12/18/2021] [Indexed: 12/01/2022] Open
Abstract
The waters that were present on early Mars may have been habitable. Characterising environments analogous to these waters and investigating the viability of their microbes under simulated martian chemical conditions is key to developing hypotheses on this habitability and potential biosignature formation. In this study, we examined the viability of microbes from the Anderton Brine Springs (United Kingdom) under simulated martian chemistries designed to simulate the chemical conditions of water that may have existed during the Hesperian. Associated changes in the fluid chemistries were also tested using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The tested Hesperian fluid chemistries were shown to be habitable, supporting the growth of all of the Anderton Brine Spring isolates. However, inter and intra-generic variation was observed both in the ability of the isolates to tolerate more concentrated fluids and in their impact on the fluid chemistry. Therefore, whilst this study shows microbes from fluctuating brines can survive and grow in simulated martian water chemistry, further investigations are required to further define the potential habitability under past martian conditions.
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Affiliation(s)
- Matthew Kelbrick
- Biology Department, Edge Hill University, Ormskirk L39 4QP, UK;
- Department of Evolution, Ecology and Behaviour, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L69 3GJ, UK
- Correspondence: (M.K.); (M.C.M.)
| | | | - Nisha K. Ramkissoon
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (S.P.S.)
| | - Amy Dugdale
- AstrobiologyOU, School of Physical Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes W23 F2H6, UK;
- Biology Department, Maynooth University, Maynooth, W23 F2H6 Kildare, Ireland
| | - Ben P. Stephens
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (S.P.S.)
| | - Ezgi Kucukkilic-Stephens
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (S.P.S.)
| | - Susanne P. Schwenzer
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (S.P.S.)
| | - André Antunes
- State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology (MUST), Macau, China;
- China National Space Administration (CNSA), Macau Center for Space Exploration and Science, Macau, China
| | - Michael C. Macey
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (S.P.S.)
- Correspondence: (M.K.); (M.C.M.)
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15
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Physicochemical Parameters Limiting Growth of Debaryomyces hansenii in Solutions of Hygroscopic Compounds and Their Effects on the Habitability of Martian Brines. Life (Basel) 2021; 11:life11111194. [PMID: 34833070 PMCID: PMC8619379 DOI: 10.3390/life11111194] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/01/2021] [Accepted: 11/04/2021] [Indexed: 11/27/2022] Open
Abstract
The availability of liquid water is a prerequisite for all lifeforms on Earth. In hyperarid subzero environments like the Dry Valleys in Antarctica or the near-subsurface of Mars liquid water might be provided temporarily by hygroscopic substances that absorb water from the atmosphere and lower the freezing point of water. To evaluate the potential of hygroscopic compounds to serve as a habitat, it is necessary to explore the microbial tolerances towards these substances and their life-limiting properties. Here we present a study investigating the tolerances of the halotolerant yeast Debaryomyces hansenii to various solutes. Growth experiments were conducted via counting colony forming units (CFUs) after inoculation of a liquid growth medium containing a specific solute concentration. The lowest water activities (aw) enabling growth were determined to be ~0.83 in glycerol and fructose-rich media. For all other solutes the growth-enabling aw was higher, due to additional stress factors such as chaotropicity and ionic strength. Additionally, we found that the solute tolerances of D. hansenii correlate with both the eutectic freezing point depressions and the deliquescence relative humidities of the respective solutes. Our findings strongly impact our understanding of the habitability of solute-rich low aw environments on Earth and beyond.
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16
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Huby TJC, Clark DR, McKew BA, McGenity TJ. Extremely halophilic archaeal communities are resilient to short-term entombment in halite. Environ Microbiol 2021; 23:3370-3383. [PMID: 31919959 PMCID: PMC8359394 DOI: 10.1111/1462-2920.14913] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 01/06/2020] [Accepted: 01/06/2020] [Indexed: 11/28/2022]
Abstract
Some haloarchaea avoid the harsh conditions present in evaporating brines by entombment in brine inclusions within forming halite crystals, where a subset of haloarchaea survives over geological time. However, shifts in the community structure of halite-entombed archaeal communities remain poorly understood. Therefore, we analysed archaeal communities from in situ hypersaline brines collected from Trapani saltern (Sicily) and their successional changes in brines versus laboratory-grown halite over 21 weeks, using high-throughput sequencing. Haloarchaea were dominant, comprising >95% of the archaeal community. Unexpectedly, the OTU richness of the communities after 21 weeks was indistinguishable from the parent brine and overall archaeal abundance in halite showed no clear temporal trends. Furthermore, the duration of entombment was less important than the parent brine from which the halite derived in determining the community composition and relative abundances of most genera in halite-entombed communities. These results show that halite-entombed archaeal communities are resilient to entombment durations of up to 21 weeks, and that entombment in halite may be an effective survival strategy for near complete communities of haloarchaea. Additionally, the dominance of 'halite specialists' observed in ancient halite must occur over periods of years, rather than months, hinting at long-term successional dynamics in this environment.
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Affiliation(s)
- Tom J. C. Huby
- School of Life SciencesUniversity of EssexColchesterEssexUK
| | - Dave R. Clark
- School of Life SciencesUniversity of EssexColchesterEssexUK
| | - Boyd A. McKew
- School of Life SciencesUniversity of EssexColchesterEssexUK
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17
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Benison KC, O'Neill WK, Blain D, Hallsworth JE. Water Activities of Acid Brine Lakes Approach the Limit for Life. ASTROBIOLOGY 2021; 21:729-740. [PMID: 33819431 PMCID: PMC8219186 DOI: 10.1089/ast.2020.2334] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 02/09/2021] [Indexed: 05/19/2023]
Abstract
Water activity is an important characteristic for describing unusual waters and is a determinant of habitability for microorganisms. However, few empirical studies of water activity have been done for natural waters exhibiting an extreme chemistry. Here, we investigate water activity for acid brines from Western Australia and Chile with pH as low as 1.4, salinities as high as 32% total dissolved solids, and complex chemical compositions. These acid brines host diverse communities of extremophilic microorganisms, including archaea, bacteria, algae, and fungi, according to metagenomic analyses. For the most extreme brine, its water activity (0.714) was considerably lower than that of saturated (pure) NaCl brine. This study provides a thermodynamic insight into life within end-member natural waters that lie at, or possibly beyond, the very edge of habitable space on Earth.
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Affiliation(s)
- Kathleen C. Benison
- Department of Geology and Geography, West Virginia University, Morgantown, West Virginia, USA
- Address correspondence to: Kathleen C. Benison, Department of Geology and Geography, West Virginia University, Morgantown, WV 26506-6300, USA
| | - William K. O'Neill
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland
| | - David Blain
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland
| | - John E. Hallsworth
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland
- Address correspondence to: John E. Hallsworth, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Garden, Belfast, BT9 5DL, Northern Ireland
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18
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Hallsworth JE. Mars' surface is not universally biocidal. Environ Microbiol 2021; 23:3345-3350. [DOI: 10.1111/1462-2920.15494] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/24/2021] [Accepted: 03/26/2021] [Indexed: 12/19/2022]
Affiliation(s)
- John E. Hallsworth
- Institute for Global Food Security, School of Biological Sciences Queen's University Belfast 19 Chlorine Gardens Belfast BT9 7BL UK
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19
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Sorokin DY, Diender M, Merkel AY, Koenen M, Bale NJ, Pabst M, Sinninghe Damsté JS, Sousa DZ. Natranaerofaba carboxydovora gen. nov., sp. nov., an extremely haloalkaliphilic CO-utilizing acetogen from a hypersaline soda lake representing a novel deep phylogenetic lineage in the class 'Natranaerobiia'. Environ Microbiol 2020; 23:3460-3476. [PMID: 32955149 PMCID: PMC8359318 DOI: 10.1111/1462-2920.15241] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/15/2020] [Accepted: 09/17/2020] [Indexed: 01/02/2023]
Abstract
An anaerobic enrichment with CO from sediments of hypersaline soda lakes resulted in a methane‐forming binary culture, whereby CO was utilized by a bacterium and not the methanogenic partner. The bacterial isolate ANCO1 forms a deep‐branching phylogenetic lineage at the level of a new family within the class ‘Natranaerobiia’. It is an extreme haloalkaliphilic and moderate thermophilic acetogen utilizing CO, formate, pyruvate and lactate as electron donors and thiosulfate, nitrate (reduced to ammonia) and fumarate as electron acceptors. The genome of ANCO1 encodes a full Wood–Ljungdahl pathway allowing for CO oxidation and acetogenic conversion of pyruvate. A locus encoding Nap nitrate reductase/NrfA ammonifying nitrite reductase is also present. Thiosulfate respiration is encoded by a Phs/Psr‐like operon. The organism obviously relies on Na‐based bioenergetics, since the genome encodes for the Na+‐Rnf complex, Na+‐F1F0 ATPase and Na+‐translocating decarboxylase. Glycine betaine serves as a compatible solute. ANCO1 has an unusual membrane polar lipid composition dominated by diethers, more common among archaea, probably a result of adaptation to multiple extremophilic conditions. Overall, ANCO1 represents a unique example of a triple extremophilic CO‐oxidizing anaerobe and is classified as a novel genus and species Natranaerofaba carboxydovora in a novel family Natranaerofabacea.
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Affiliation(s)
- Dimitry Y Sorokin
- Winogradsky Institute of Microbiology, Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, Russia.,Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Martijn Diender
- Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands
| | - Alexander Y Merkel
- Winogradsky Institute of Microbiology, Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Michel Koenen
- NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, Utrecht University, Den Burg, The Netherlands
| | - Nicole J Bale
- NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, Utrecht University, Den Burg, The Netherlands
| | - Martin Pabst
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Jaap S Sinninghe Damsté
- NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, Utrecht University, Den Burg, The Netherlands.,Department of Geosciences, Utrecht University, Utrecht, The Netherlands
| | - Diana Z Sousa
- Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands
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20
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Capacity of Chlorate to Oxidize Ferrous Iron: Implications for Iron Oxide Formation on Mars. MINERALS 2020. [DOI: 10.3390/min10090729] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Chlorate is an important Cl-bearing species and a strong potential Fe(II) oxidant on Mars. Since the amount of oxychlorine species (perchlorate and chlorate) detected on Mars is limited (<~1 wt.%), the effectiveness of chlorate to produce iron oxides depends heavily on its oxidizing capacity. Decomposition of chlorate or intermediates produced during its reduction, before reaction with Fe(II) would decrease its effective capacity as an oxidant. We thus evaluated the capacity of chlorate to produce Fe(III) minerals in Mars-relevant fluids, via oxidation of dissolved Fe(II). Each chlorate ion can oxidize 6 Fe(II) ions under all conditions investigated. Mass balance demonstrated that 1 wt.% chlorate (as ClO3−) could produce approximately 6 to 12 wt.% Fe(III) or mixed valent mineral products, with the amount varying with the formula of the precipitating phase. The mineral products are primarily determined by the fluid type (chloride- or sulfate-rich), the solution pH, and the rate of Fe(II) oxidation. The pH at the time of initial mineral nucleation and the amount of residual dissolved Fe(II) in the system exert important additional controls on the final mineralogy. Subsequent diagenetic transformation of these phases would yield 5.7 wt.% hematite per wt.% of chlorate reacted, providing a quantitative constraint on the capacity of chlorate to generate iron oxides on Mars.
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21
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Timson DJ, Eardley J. Destressing Yeast for Higher Biofuel Yields: Can Excess Chaotropicity Be Mitigated? Appl Biochem Biotechnol 2020; 192:1368-1375. [PMID: 32803494 DOI: 10.1007/s12010-020-03406-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 08/12/2020] [Indexed: 11/24/2022]
Abstract
Biofuels have the capacity to contribute to carbon dioxide emission reduction and to energy security as oil reserves diminish and/or become concentrated in politically unstable regions. However, challenges exist in obtaining the maximum yield from industrial fermentations. One challenge arises from the nature of alcohols. These compounds are chaotropic (i.e. causes disorder in the system) which causes stress in the microbes producing the biofuel. Brewer's yeast (Saccharomyces cerevisiae) typically cannot grow at ethanol concentration much above 17% (v/v). Mitigation of these properties has the potential to increase yield. Previously, we have explored the effects of chaotropes on model enzyme systems and attempted (largely unsuccessfully) to offset these effects by kosmotropes (compounds which increase the order of the system, i.e. the "opposite" of chaotropes). Here we present some theoretical results which suggest that high molecular mass polyethylene glycols may be the most effective kosmotropic additives in terms of both efficacy and cost. The assumptions and limitations of these calculations are also presented. A deeper understanding of the effects of chaotropes on biofuel-producing microbes is likely to inform improvements in bioethanol yields and enable more rational approaches to the "neutralisation" of chaotropicity.
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Affiliation(s)
- David J Timson
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Huxley Building, Lewes Road, Brighton, BN2 4GJ, UK.
| | - Joshua Eardley
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Huxley Building, Lewes Road, Brighton, BN2 4GJ, UK
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22
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Waajen AC, Heinz J, Airo A, Schulze-Makuch D. Physicochemical Salt Solution Parameters Limit the Survival of Planococcus halocryophilus in Martian Cryobrines. Front Microbiol 2020; 11:1284. [PMID: 32733393 PMCID: PMC7358355 DOI: 10.3389/fmicb.2020.01284] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 05/20/2020] [Indexed: 11/13/2022] Open
Abstract
Microorganisms living in sub-zero environments can benefit from the presence of dissolved salts, as they significantly increase the temperature range of liquid water by lowering the freezing point. However, high concentrations of salts can reduce microbial growth and survival, and can evoke a physiological stress response. It remains poorly understood how the physicochemical parameters of brines (e.g. water activity, ionic strength, solubility and hydration shell strength between the ions and the surrounding water molecules) influence the survival of microorganisms. We used the cryo- and halotolerant bacterial strain Planococcus halocryophilus as a model organism to evaluate the degree of stress different salts assert. Cells were incubated in liquid media at -15°C containing single salts at eutectic concentrations (CaCl2, LiCl, LiI, MgBr2, MgCl2, NaBr, NaCl, NaClO4 and NaI). Four of these salts (LiCl, LiI, MgBr2 and NaClO4) were also investigated at concentrations with a low water activity (0.635) and, separately, with a high ionic strength (8 mol/L). Water activity of all solutions was measured at -15°C. This is the first time that water activity has been measured for such a large number of liquid salt solutions at constant sub-zero temperatures (-15°C). Colony-Forming Unit (CFU) counts show that the survival of P. halocryophilus has a negative correlation with the salt concentration, molecular weight of the anion and anion radius; and a positive correlation with the water activity and anions' hydration shell strength. The survival of P. halocryophilus did not show a significant correlation with the ionic strength, the molecular weight of the cation, the hydrated and unhydrated cation and hydrated anion radius, and the cations' hydration bond length. Thus, the water activity, salt concentration and anion parameters play the largest role in the survival of P. halocryophilus in concentrated brines. These findings improve our understanding of the limitations of microbial life in saline environments, which provides a basis for better evaluation of the habitability of extraterrestrial environments such as Martian cryobrines.
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Affiliation(s)
- Annemiek C Waajen
- UK Centre for Astrobiology, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, United Kingdom.,Astrobiology Research Group, Center of Astronomy and Astrophysics, Technische Universität Berlin, Berlin, Germany
| | - Jacob Heinz
- Astrobiology Research Group, Center of Astronomy and Astrophysics, Technische Universität Berlin, Berlin, Germany
| | - Alessandro Airo
- Astrobiology Research Group, Center of Astronomy and Astrophysics, Technische Universität Berlin, Berlin, Germany
| | - Dirk Schulze-Makuch
- Astrobiology Research Group, Center of Astronomy and Astrophysics, Technische Universität Berlin, Berlin, Germany.,School of the Environment, Washington State University, Pullman, WA, United States.,Section Geomicrobiology, GFZ German Research Centre for Geosciences, Potsdam, Germany.,Department of Experimental Limnology, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Stechlin, Germany
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23
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Cockell CS, McLean CM, Perera L, Aka S, Stevens A, Dickinson AW. Growth of Non-Halophilic Bacteria in the Sodium-Magnesium-Sulfate-Chloride Ion System: Unravelling the Complexities of Ion Interactions in Terrestrial and Extraterrestrial Aqueous Environments. ASTROBIOLOGY 2020; 20:944-955. [PMID: 32434375 DOI: 10.1089/ast.2019.2092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Motivated by an interest in understanding the habitability of aqueous environments on Earth and in extraterrestrial settings, this study investigated the influence of ions in an artificial sodium-magnesium-sulfate-chloride ion system on the growth parameters (lag phase, growth rate, and final cell concentration) of bacteria. These four ions, in different combinations, are key components of many aqueous environments on Earth and elsewhere. We investigated non-halophilic bacteria deliberately to remove the bias of prior adaptations to high concentrations of selected ions so that we could compare the effects of different ions. We tested the hypothesis that water activity determined the growth parameters independent of the ion types. Neither water activity or ionic strength alone could predict growth. However, when ionic strengths were matched, many differences in growth parameters could be explained by the water activity. We suggest that species-specific effects (caused by differences in biochemical and physiological influences), the role of individual ions in cellular processes, and potentially the chaotropicity and kosmotropicity of solutions influenced the growth. Our data show that although extreme combinations of these ions allow for general predictions on the habitability of extraterrestrial aqueous environments, a complex interplay of ionic effects influences the growth and thus the adaptations required for given ion combinations. The data also show that an accurate quantification of the habitability of ocean worlds, such as Europa and Enceladus, can only be made when samples are obtained from these water bodies and the ion combinations are determined.
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Affiliation(s)
- Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Claire-Marie McLean
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Liam Perera
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Salomé Aka
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Adam Stevens
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Andrew W Dickinson
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
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24
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Macey MC, Fox-Powell M, Ramkissoon NK, Stephens BP, Barton T, Schwenzer SP, Pearson VK, Cousins CR, Olsson-Francis K. The identification of sulfide oxidation as a potential metabolism driving primary production on late Noachian Mars. Sci Rep 2020; 10:10941. [PMID: 32616785 PMCID: PMC7331718 DOI: 10.1038/s41598-020-67815-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 06/15/2020] [Indexed: 01/11/2023] Open
Abstract
The transition of the martian climate from the wet Noachian era to the dry Hesperian (4.1-3.0 Gya) likely resulted in saline surface waters that were rich in sulfur species. Terrestrial analogue environments that possess a similar chemistry to these proposed waters can be used to develop an understanding of the diversity of microorganisms that could have persisted on Mars under such conditions. Here, we report on the chemistry and microbial community of the highly reducing sediment of Colour Peak springs, a sulfidic and saline spring system located within the Canadian High Arctic. DNA and cDNA 16S rRNA gene profiling demonstrated that the microbial community was dominated by sulfur oxidising bacteria, suggesting that primary production in the sediment was driven by chemolithoautotrophic sulfur oxidation. It is possible that the sulfur oxidising bacteria also supported the persistence of the additional taxa. Gibbs energy values calculated for the brines, based on the chemistry of Gale crater, suggested that the oxidation of reduced sulfur species was an energetically viable metabolism for life on early Mars.
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Affiliation(s)
- M C Macey
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, UK.
| | - M Fox-Powell
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, UK
- School of Earth and Environmental Sciences, University of St Andrews, Irvine Building, St Andrews, UK
| | - N K Ramkissoon
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, UK
| | - B P Stephens
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, UK
| | - T Barton
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, UK
| | - S P Schwenzer
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, UK
| | - V K Pearson
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, UK
| | - C R Cousins
- School of Earth and Environmental Sciences, University of St Andrews, Irvine Building, St Andrews, UK
| | - K Olsson-Francis
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, UK
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25
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Stevens AH, Cockell CS. A Systematic Study of the Limits of Life in Mixed Ion Solutions: Physicochemical Parameters Do Not Predict Habitability. Front Microbiol 2020; 11:1478. [PMID: 32670258 PMCID: PMC7332579 DOI: 10.3389/fmicb.2020.01478] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/08/2020] [Indexed: 11/13/2022] Open
Abstract
This study investigated what defines the limits of life in mixed ion solutions. Better understanding these limits should allow us to better predict the habitability of extreme environments on the Earth and extraterrestrial environments. We systematically examined the response of Bacillus subtilis, a well characterized non-halophile model organism, to a range of solutions made from single and mixed salts up to their solubility limits and measured at what concentration growth was arrested, specifically exploring Na, Mg, and Ca cations and Cl, SO4, and ClO4 anions. We measured the physicochemical properties of the solutions to identify which properties correlated with the limits of growth. Individual salts imposed a growth limit specific to the combination of cation and anion, although we generally observe that chloride salts allow growth at lower water activity than sulfate salts, with perchlorate restricting growth even at the highest measured water activity. Growth was limited at a wide range of ionic strength, with no apparently correlation. Despite the theoretically counteracting disordering effects (chaotropic) of perchlorates and ordering effects (kosmotropic) effects of sulfates, when these salts were combined they instead additively narrowed the window for growth in both the Na and Mg cation systems, in the same manner as the combined effects of two chaotropic Ca salts. Our results imply that away from hard limits that might be imposed by physicochemical properties such as water activity, ionic strength or chaotropicity in highly concentrated brines, these properties do not set the limits of life. Instead these limits are highly specific to the salts and organisms in question. This specificity means that the habitability of extreme environments cannot be predicted, even with accurate measurements of the physicochemical conditions present.
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Affiliation(s)
- Adam H. Stevens
- UK Centre for Astrobiology, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, United Kingdom
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26
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Drissi Kaitouni LB, Anissi J, Sendide K, El Hassouni M. Diversity of hydrolase-producing halophilic bacteria and evaluation of their enzymatic activities in submerged cultures. ANN MICROBIOL 2020. [DOI: 10.1186/s13213-020-01570-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Purpose
In this work, we assessed the diversity of culturable halophilic bacteria that produce hydrolytic enzymes from both natural and artificial hypersaline regions in the pre-Rif region of Morocco.
Methods
Bacteria were isolated from three hypersaline sites, in solid medium supplemented with various salt concentrations ranging from 0 to 330 g/L. Physical and chemical characteristics of samples from the isolation site were determined to suggest eventual correlations with the occurrence of the halophilic bacteria. Assays on enzymatic activities were performed in submerged cultures in the presence of various salt concentrations and appropriate substrates.
Results
Out of a collection of 227 halophilic bacteria, four halophilic groups were established as slightly halophilic, moderately halophilic, halotolerant, or extremely halophilic, with a predominance of halophilic bacteria in the natural hypersaline sites compared to the artificial one. Within this collection, 189 strains showed important hydrolytic activities in submerged cultures with enzymatic activities up to 76 U/mg. Strain characterization and identification was based on phenotypic and molecular traits and allowed the identification of at least 26 genera including Bacillus, Chthonibacter, Mariniabilia, Halobacillus, Salinococcus, Cerasicoccus, Ulvibacter, Halorubrum, Jeatgalicoccus, Brevibacterium, Sanguibacter, Shewanella, Exiguobacterium, Gemella, and Planomicrobium.
Conclusion
Data from this study give insights about the origin and the occurrence of halophilic bacteria in natural hypersaline environments compared to artificial hypersaline sites. The occurrence of halophilic hydrolase enzymes from halophilic bacteria gives insights to different applications in biotechnology, thanks to their ability to produce adaptive enzymes and survival strategies to overcome harsh conditions.
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27
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Cockell CS. Persistence of Habitable, but Uninhabited, Aqueous Solutions and the Application to Extraterrestrial Environments. ASTROBIOLOGY 2020; 20:617-627. [PMID: 32105517 DOI: 10.1089/ast.2019.2179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In most environments on Earth, habitable environments contain life. Experiments were conducted to investigate the decoupling of the presence of habitable conditions and life. A set of microcosms habitable for known groups of organisms, but uninhabited (i.e., uninhabited habitats), was exposed to external environmental conditions to test the hypothesis that extreme habitable environments can remain uninhabited for sustained time periods. These microcosms were made of tubes containing liquid water and inorganic N, P, and S. Organics (used as electron donors and as a C source) were provided as L and D amino acids. One set of uninhabited habitats contained no additional salts, one set contained saturated NaCl, and one set contained saturated MgSO4. A ddH2O control and a complex medium for Halobacterium were used as controls. The presence of organisms was tested by enumeration of colonists and sequencing of extracted DNA. At each time point, inoculation into fresh medium was used to test for growth of organisms. After 1 week, the "no salt" and saturated MgSO4 solutions were colonized. After 6 months, both the NaCl-saturated and Halobacterium solutions remained uninhabited, but all other samples were colonized. These experiments demonstrate that certain types of habitable liquid water environments exposed to microbial atmospheric inoculation, even on Earth, can remain devoid of reproducing life for many months. On other planetary bodies, such as Mars, these data imply the possibility of preserved transient water bodies that would record habitable conditions, but no evidence of life, even if life existed elsewhere on the planet.
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Affiliation(s)
- Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, James Clerk Maxwell Building, The King's Buildings, University of Edinburgh, Edinburgh, United Kingdom
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28
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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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29
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Baricz A, Chiriac CM, Andrei AȘ, Bulzu PA, Levei EA, Cadar O, Battes KP, Cîmpean M, Șenilă M, Cristea A, Muntean V, Alexe M, Coman C, Szekeres EK, Sicora CI, Ionescu A, Blain D, O'Neill WK, Edwards J, Hallsworth JE, Banciu HL. Spatio-temporal insights into microbiology of the freshwater-to-hypersaline, oxic-hypoxic-euxinic waters of Ursu Lake. Environ Microbiol 2020; 23:3523-3540. [PMID: 31894632 DOI: 10.1111/1462-2920.14909] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 12/22/2019] [Accepted: 12/26/2019] [Indexed: 12/30/2022]
Abstract
Ursu Lake is located in the Middle Miocene salt deposit of Central Romania. It is stratified, and the water column has three distinct water masses: an upper freshwater-to-moderately saline stratum (0-3 m), an intermediate stratum exhibiting a steep halocline (3-3.5 m), and a lower hypersaline stratum (4 m and below) that is euxinic (i.e. anoxic and sulphidic). Recent studies have characterized the lake's microbial taxonomy and given rise to intriguing ecological questions. Here, we explore whether the communities are dynamic or stable in relation to taxonomic composition, geochemistry, biophysics, and ecophysiological functions during the annual cycle. We found: (i) seasonally fluctuating, light-dependent communities in the upper layer (≥0.987-0.990 water-activity), a stable but phylogenetically diverse population of heterotrophs in the hypersaline stratum (water activities down to 0.762) and a persistent plate of green sulphur bacteria that connects these two (0.958-0.956 water activity) at 3-3.5 to 4 m; (ii) communities that might be involved in carbon- and sulphur-cycling between and within the lake's three main water masses; (iii) uncultured lineages including Acetothermia (OP1), Cloacimonetes (WWE1), Marinimicrobia (SAR406), Omnitrophicaeota (OP3), Parcubacteria (OD1) and other Candidate Phyla Radiation bacteria, and SR1 in the hypersaline stratum (likely involved in the anaerobic steps of carbon- and sulphur-cycling); and (iv) that species richness and habitat stability are associated with high redox-potentials. Ursu Lake has a unique and complex ecology, at the same time exhibiting dynamic fluctuations and stability, and can be used as a modern analogue for ancient euxinic water bodies and comparator system for other stratified hypersaline systems.
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Affiliation(s)
- Andreea Baricz
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeş-Bolyai University, 5-7 Clinicilor Str., 400006, Cluj-Napoca, Romania
| | - Cecilia Maria Chiriac
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeş-Bolyai University, 5-7 Clinicilor Str., 400006, Cluj-Napoca, Romania.,National Institute of Research and Development for Biological Sciences, Institute of Biological Research, 48 Republicii Str., 400015, Cluj-Napoca, Romania
| | - Adrian-Ștefan Andrei
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeş-Bolyai University, 5-7 Clinicilor Str., 400006, Cluj-Napoca, Romania.,Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sádkách 702/7, 370 05 České, Budějovice, Czech Republic
| | - Paul-Adrian Bulzu
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeş-Bolyai University, 5-7 Clinicilor Str., 400006, Cluj-Napoca, Romania.,Institute for Interdisciplinary Research in Bio-Nano-Sciences, 42 A. Treboniu Laurian Str., Babeş-Bolyai University, 400271, Cluj-Napoca, Romania
| | - Erika Andrea Levei
- INCDO-INOE 2000, Research Institute for Analytical Instrumentation, 67 Donath Str., 400293, Cluj-Napoca, Romania
| | - Oana Cadar
- INCDO-INOE 2000, Research Institute for Analytical Instrumentation, 67 Donath Str., 400293, Cluj-Napoca, Romania
| | - Karina Paula Battes
- Department of Taxonomy and Ecology, Faculty of Biology and Geology, Babeş-Bolyai University, 5-7 Clinicilor Str., 400006, Cluj-Napoca, Romania
| | - Mirela Cîmpean
- Department of Taxonomy and Ecology, Faculty of Biology and Geology, Babeş-Bolyai University, 5-7 Clinicilor Str., 400006, Cluj-Napoca, Romania
| | - Marin Șenilă
- INCDO-INOE 2000, Research Institute for Analytical Instrumentation, 67 Donath Str., 400293, Cluj-Napoca, Romania
| | - Adorján Cristea
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeş-Bolyai University, 5-7 Clinicilor Str., 400006, Cluj-Napoca, Romania.,Institute for Interdisciplinary Research in Bio-Nano-Sciences, 42 A. Treboniu Laurian Str., Babeş-Bolyai University, 400271, Cluj-Napoca, Romania
| | - Vasile Muntean
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeş-Bolyai University, 5-7 Clinicilor Str., 400006, Cluj-Napoca, Romania
| | - Mircea Alexe
- Department of Physical and Technical Geography, Faculty of Geography, Babeş-Bolyai University, 5-7 Clinicilor Str., 400006, Cluj-Napoca, Romania
| | - Cristian Coman
- National Institute of Research and Development for Biological Sciences, Institute of Biological Research, 48 Republicii Str., 400015, Cluj-Napoca, Romania
| | - Edina Kriszta Szekeres
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeş-Bolyai University, 5-7 Clinicilor Str., 400006, Cluj-Napoca, Romania.,National Institute of Research and Development for Biological Sciences, Institute of Biological Research, 48 Republicii Str., 400015, Cluj-Napoca, Romania
| | - Cosmin Ionel Sicora
- Biological Research Center Jibou, 16 Wesselenyi Miklos Str., 455200, Jibou, Romania
| | - Artur Ionescu
- Faculty of Environmental Science and Engineering, Babeş-Bolyai University, 30 Fantanele Str., 400294, Cluj-Napoca, Romania
| | - David Blain
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 7BL, UK
| | - William Kenneth O'Neill
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 7BL, UK
| | - Jessica Edwards
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 7BL, UK
| | - John Edward Hallsworth
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 7BL, UK
| | - Horia Leonard Banciu
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeş-Bolyai University, 5-7 Clinicilor Str., 400006, Cluj-Napoca, Romania.,Institute for Interdisciplinary Research in Bio-Nano-Sciences, 42 A. Treboniu Laurian Str., Babeş-Bolyai University, 400271, Cluj-Napoca, Romania
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30
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Taubner RS, Olsson-Francis K, Vance SD, Ramkissoon NK, Postberg F, de Vera JP, Antunes A, Camprubi Casas E, Sekine Y, Noack L, Barge L, Goodman J, Jebbar M, Journaux B, Karatekin Ö, Klenner F, Rabbow E, Rettberg P, Rückriemen-Bez T, Saur J, Shibuya T, Soderlund KM. Experimental and Simulation Efforts in the Astrobiological Exploration of Exooceans. SPACE SCIENCE REVIEWS 2020; 216:9. [PMID: 32025060 PMCID: PMC6977147 DOI: 10.1007/s11214-020-0635-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 01/06/2020] [Indexed: 05/05/2023]
Abstract
The icy satellites of Jupiter and Saturn are perhaps the most promising places in the Solar System regarding habitability. However, the potential habitable environments are hidden underneath km-thick ice shells. The discovery of Enceladus' plume by the Cassini mission has provided vital clues in our understanding of the processes occurring within the interior of exooceans. To interpret these data and to help configure instruments for future missions, controlled laboratory experiments and simulations are needed. This review aims to bring together studies and experimental designs from various scientific fields currently investigating the icy moons, including planetary sciences, chemistry, (micro-)biology, geology, glaciology, etc. This chapter provides an overview of successful in situ, in silico, and in vitro experiments, which explore different regions of interest on icy moons, i.e. a potential plume, surface, icy shell, water and brines, hydrothermal vents, and the rocky core.
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Affiliation(s)
- Ruth-Sophie Taubner
- Archaea Biology and Ecogenomics Division, University of Vienna, Vienna, Austria
| | | | | | | | | | | | - André Antunes
- State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau SAR, China
| | | | | | - Lena Noack
- Freie Universität Berlin, Berlin, Germany
| | | | | | | | | | | | | | - Elke Rabbow
- German Aerospace Center (DLR), Cologne, Germany
| | | | | | | | - Takazo Shibuya
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
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32
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Belilla J, Moreira D, Jardillier L, Reboul G, Benzerara K, López-García JM, Bertolino P, López-Archilla AI, López-García P. Hyperdiverse archaea near life limits at the polyextreme geothermal Dallol area. Nat Ecol Evol 2019; 3:1552-1561. [PMID: 31666740 PMCID: PMC6837875 DOI: 10.1038/s41559-019-1005-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 09/16/2019] [Indexed: 11/13/2022]
Abstract
Microbial life has adapted to various individual extreme conditions; yet, organisms simultaneously adapted to very low pH, high salt and high temperature are unknown. We combined environmental 16S/18S rRNA-gene metabarcoding, cultural approaches, fluorescence-activated cell sorting, scanning electron microscopy and chemical analyses to study samples along such unique polyextreme gradients in the Dallol-Danakil area (Ethiopia). We identify two physicochemical barriers to life in the presence of surface liquid water defined by: i) high chaotropicity-low water activity in Mg2+/Ca2+-dominated brines and ii) hyperacidity-salt combinations (pH~0/NaCl-dominated salt-saturation). When detected, life was dominated by highly diverse ultrasmall archaea widely distributed across phyla with and without previously known halophilic members. We hypothesize that high cytoplasmic K+-level was an original archaeal adaptation to hyperthermophily, subsequently exapted during multiple transitions to extreme halophily. We detect active silica encrustment/fossilization of cells but also abiotic biomorphs of varied chemistry. Our work helps circumscribing habitability and calls for cautionary interpretations of morphological biosignatures on Earth and beyond.
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Affiliation(s)
- Jodie Belilla
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - David Moreira
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Ludwig Jardillier
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Guillaume Reboul
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Karim Benzerara
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, CNRS, Sorbonne Université, Muséum National d'Histoire Naturelle, Paris, France
| | | | - Paola Bertolino
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | | | - Purificación López-García
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France.
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33
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Eardley J, Dedi C, Dymond M, Hallsworth JE, Timson DJ. Evidence for chaotropicity/kosmotropicity offset in a yeast growth model. Biotechnol Lett 2019; 41:1309-1318. [DOI: 10.1007/s10529-019-02737-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 09/20/2019] [Indexed: 11/28/2022]
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Habitability of Mars: How Welcoming Are the Surface and Subsurface to Life on the Red Planet? GEOSCIENCES 2019. [DOI: 10.3390/geosciences9090361] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mars is a planet of great interest in the search for signatures of past or present life beyond Earth. The years of research, and more advanced instrumentation, have yielded a lot of evidence which may be considered by the scientific community as proof of past or present habitability of Mars. Recent discoveries including seasonal methane releases and a subglacial lake are exciting, yet challenging findings. Concurrently, laboratory and environmental studies on the limits of microbial life in extreme environments on Earth broaden our knowledge of the possibility of Mars habitability. In this review, we aim to: (1) Discuss the characteristics of the Martian surface and subsurface that may be conducive to habitability either in the past or at present; (2) discuss laboratory-based studies on Earth that provide us with discoveries on the limits of life; and (3) summarize the current state of knowledge in terms of direction for future research.
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Cubillos CF, Paredes A, Yáñez C, Palma J, Severino E, Vejar D, Grágeda M, Dorador C. Insights Into the Microbiology of the Chaotropic Brines of Salar de Atacama, Chile. Front Microbiol 2019; 10:1611. [PMID: 31354691 PMCID: PMC6637823 DOI: 10.3389/fmicb.2019.01611] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 06/27/2019] [Indexed: 02/02/2023] Open
Abstract
Microbial life inhabiting hypersaline environments belong to a limited group of extremophile or extremotolerant taxa. Natural or artificial hypersaline environments are not limited to high concentrations of NaCl, and under such conditions, specific adaptation mechanisms are necessary to permit microbial survival and growth. Argentina, Bolivia, and Chile include three large salars (salt flats) which globally, represent the largest lithium reserves, and are commonly referred to as the Lithium Triangle Zone. To date, a large amount of information has been generated regarding chemical, geological, meteorological and economical perspectives of these salars. However, there is a remarkable lack of information regarding the biology of these unique environments. Here, we report the presence of two bacterial strains (isolates LIBR002 and LIBR003) from one of the most hypersaline lithium-dominated man-made environments (total salinity 556 g/L; 11.7 M LiCl) reported to date. Both isolates were classified to the Bacillus genera, but displayed differences in 16S rRNA gene and fatty acid profiles. Our results also revealed that the isolates are lithium-tolerant and that they are phylogenetically differentiated from those Bacillus associated with high NaCl concentration environments, and form a new clade from the Lithium Triangle Zone. To determine osmoadaptation strategies in these microorganisms, both isolates were characterized using morphological, metabolic and physiological attributes. We suggest that our characterization of bacterial isolates from a highly lithium-enriched environment has revealed that even at such extreme salinities with high concentrations of chaotropic solutes, scope for microbial life exists. These conditions have previously been considered to limit the development of life, and our work extends the window of life beyond high concentrations of MgCl2, as previously reported, to LiCl. Our results can be used to further the understanding of salt tolerance, most especially for LiCl-dominated brines, and likely have value as models for the understanding of putative extra-terrestrial (e.g., Martian) life.
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Affiliation(s)
- Carolina F. Cubillos
- Laboratorio de Complejidad Microbiana y Ecología Funcional, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
- Department of Chemical Engineering and Mineral Process, Center for Advanced Study of Lithium and Industrial Minerals, Universidad de Antofagasta, Antofagasta, Chile
- Centre for Biotechnology and Bioengineering, Universidad de Chile, Santiago, Chile
| | - Adrián Paredes
- Laboratorio Química Biológica, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
- Departamento de Química, Facultad de Ciencias Básicas, Universidad de Antofagasta, Antofagasta, Chile
| | - Carolina Yáñez
- Laboratorio Microbiología, Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Jenifer Palma
- Departamento de Ciencias de los Alimentos, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
| | - Esteban Severino
- Laboratorio de Complejidad Microbiana y Ecología Funcional, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
| | - Drina Vejar
- Laboratorio de Complejidad Microbiana y Ecología Funcional, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
- Centre for Biotechnology and Bioengineering, Universidad de Chile, Santiago, Chile
| | - Mario Grágeda
- Department of Chemical Engineering and Mineral Process, Center for Advanced Study of Lithium and Industrial Minerals, Universidad de Antofagasta, Antofagasta, Chile
| | - Cristina Dorador
- Laboratorio de Complejidad Microbiana y Ecología Funcional, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
- Centre for Biotechnology and Bioengineering, Universidad de Chile, Santiago, Chile
- Departamento de Biotecnología, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Antofagasta, Chile
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Crisler JD, Chen F, Clark BC, Schneegurt MA. Cultivation and characterization of the bacterial assemblage of epsomic Basque Lake, BC. Antonie Van Leeuwenhoek 2019; 112:1105-1119. [PMID: 30737709 PMCID: PMC6548648 DOI: 10.1007/s10482-019-01244-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 01/29/2019] [Indexed: 01/21/2023]
Abstract
Athalassohaline waters that are rich in divalent ions are good analogues for the chemical environments of Mars and the ocean worlds. Sulfate salts, along with chlorides, are important in Mars regolith with Ca, Fe, Mg, and Na counterions. Certain lakes in the Pacific Northwest are saturated with MgSO4 as epsomite. Here we report on the microbial community of Basque Lake, BC, a group of playas that is saturated with MgSO4. More than 60 bacterial isolates were obtained from Basque Lake soils by enrichment culture and repetitive streak-plating using media containing 10% (~ 1.7 M) NaCl or 50% (~ 2 M) MgSO4. Most of the isolates (~ 75%) were Gram-positive, motile, and produced endospores. Isolates related to Marinococcus halophilus and Virgibacillus marismortui dominated the collection. Halomonas and Salinivibrio were Gram-negative genera found at Basque Lake. Nearly all of the Basque Lake isolates grew at 50% MgSO4, with 65% growing at 60% MgSO4. Several isolates could grow in saturated (67%) MgSO4 (aw = 0.90). All of the isolates grew at 10% NaCl with 70% growing at 20% salinity (~ 3.5 M NaCl; aw = 0.82). Basque Lake isolates grew better at basic pH than acidic pH, with 80% growing at pH 9 and 30% growing at pH 10. Only 20% of the isolates grew at pH 5. Numerical taxonomy dendrograms based on 44 phenetic characteristics showed a strong correspondence to phylogenetic trees constructed from 16S rRNA gene sequences. Pyrosequencing of 16S rRNA gene sequences from direct DNA extracts of Basque Lake soils recovered predominantly Proteobacteria (60%), Firmicutes (11%), and unclassified bacteria (27%). Microbes capable of growth under the extreme chemical conditions of Mars are a particular concern for forward planetary protection should they contaminate a spacecraft.
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Affiliation(s)
- James D Crisler
- Department of Biological Sciences, Wichita State University, 26, 1845 Fairmount, Wichita, KS, 67260, USA
| | - Fei Chen
- Planetary Protection Group, Jet Propulsion Laboratory, NASA, Pasadena, CA, USA
| | | | - Mark A Schneegurt
- Department of Biological Sciences, Wichita State University, 26, 1845 Fairmount, Wichita, KS, 67260, USA.
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Payler SJ, Biddle JF, Sherwood Lollar B, Fox-Powell MG, Edwards T, Ngwenya BT, Paling SM, Cockell CS. An Ionic Limit to Life in the Deep Subsurface. Front Microbiol 2019; 10:426. [PMID: 30915051 PMCID: PMC6422919 DOI: 10.3389/fmicb.2019.00426] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 02/19/2019] [Indexed: 11/18/2022] Open
Abstract
The physical and chemical factors that can limit or prevent microbial growth in the deep subsurface are not well defined. Brines from an evaporite sequence were sampled in the Boulby Mine, United Kingdom between 800 and 1300 m depth. Ionic, hydrogen and oxygen isotopic composition were used to identify two brine sources, an aquifer situated in strata overlying the mine, and another ambiguous source distinct from the regional groundwater. The ability of the brines to support microbial replication was tested with culturing experiments using a diversity of inocula. The examined brines were found to be permissive for growth, except one. Testing this brine's physicochemical properties showed it to have low water activity and to be chaotropic, which we attribute to the high concentration of magnesium and chloride ions. Metagenomic sequencing of the brines that supported growth showed their microbial communities to be similar to each other and comparable to those found in other hypersaline environments. These data show that solutions high in dissolved ions can shape the microbial diversity of the continental deep subsurface biosphere. Furthermore, under certain circumstances, complex brines can establish a hard limit to microbial replication in the deep biosphere, highlighting the potential for subsurface uninhabitable aqueous environments at depths far shallower than a geothermally-defined limit to life.
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Affiliation(s)
- Samuel J. Payler
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Jennifer F. Biddle
- College of Earth, Ocean, and Environment, University of Delaware, Lewes, DE, United States
| | | | - Mark G. Fox-Powell
- School of Earth and Environmental Sciences, University of St. Andrews, St. Andrews, United Kingdom
| | | | - Bryne T. Ngwenya
- School of Geosciences, Kings Buildings, University of Edinburgh, Edinburgh, United Kingdom
| | - Sean M. Paling
- Boulby Underground Science Facility, Science and Technology Facilities Council, Swindon, United Kingdom
| | - Charles S. Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
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Cortesão M, Fuchs FM, Commichau FM, Eichenberger P, Schuerger AC, Nicholson WL, Setlow P, Moeller R. Bacillus subtilis Spore Resistance to Simulated Mars Surface Conditions. Front Microbiol 2019; 10:333. [PMID: 30863384 PMCID: PMC6399134 DOI: 10.3389/fmicb.2019.00333] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 02/08/2019] [Indexed: 11/13/2022] Open
Abstract
In a Mars exploration scenario, knowing if and how highly resistant Bacillus subtilis spores would survive on the Martian surface is crucial to design planetary protection measures and avoid false positives in life-detection experiments. Therefore, in this study a systematic screening was performed to determine whether B. subtilis spores could survive an average day on Mars. For that, spores from two comprehensive sets of isogenic B. subtilis mutant strains, defective in DNA protection or repair genes, were exposed to 24 h of simulated Martian atmospheric environment with or without 8 h of Martian UV radiation [M(+)UV and M(-)UV, respectively]. When exposed to M(+)UV, spore survival was dependent on: (1) core dehydration maintenance, (2) protection of DNA by α/β-type small acid soluble proteins (SASP), and (3) removal and repair of the major UV photoproduct (SP) in spore DNA. In turn, when exposed to M(-)UV, spore survival was mainly dependent on protection by the multilayered spore coat, and DNA double-strand breaks represent the main lesion accumulated. Bacillus subtilis spores were able to survive for at least a limited time in a simulated Martian environment, both with or without solar UV radiation. Moreover, M(-)UV-treated spores exhibited survival rates significantly higher than the M(+)UV-treated spores. This suggests that on a real Martian surface, radiation shielding of spores (e.g., by dust, rocks, or spacecraft surface irregularities) might significantly extend survival rates. Mutagenesis were strongly dependent on the functionality of all structural components with small acid-soluble spore proteins, coat layers and dipicolinic acid as key protectants and efficiency DNA damage removal by AP endonucleases (ExoA and Nfo), non-homologous end joining (NHEJ), mismatch repair (MMR) and error-prone translesion synthesis (TLS). Thus, future efforts should focus on: (1) determining the DNA damage in wild-type spores exposed to M(+/-)UV and (2) assessing spore survival and viability with shielding of spores via Mars regolith and other relevant materials.
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Affiliation(s)
- Marta Cortesão
- Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Felix M Fuchs
- Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Fabian M Commichau
- Department of General Microbiology, Institute for Microbiology and Genetics, University of Göttingen, Göttingen, Germany
| | - Patrick Eichenberger
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY, United States
| | - Andrew C Schuerger
- Department of Plant Pathology, Space Life Sciences Laboratory, University of Florida, Merritt Island, FL, United States
| | - Wayne L Nicholson
- Department of Microbiology and Cell Science, Space Life Sciences Laboratory, University of Florida, Merritt Island, FL, United States
| | - Peter Setlow
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, United States
| | - Ralf Moeller
- Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
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Stevens AH, Childers D, Fox-Powell M, Nicholson N, Jhoti E, Cockell CS. Growth, Viability, and Death of Planktonic and Biofilm Sphingomonas desiccabilis in Simulated Martian Brines. ASTROBIOLOGY 2019; 19:87-98. [PMID: 30048150 PMCID: PMC6338574 DOI: 10.1089/ast.2018.1840] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 06/12/2018] [Indexed: 05/22/2023]
Abstract
Aqueous solutions on Mars are theorized to contain very different ion compositions than those on Earth. To determine the effect of such solutions on typical environmental micro-organisms, which could be released from robotic spacecraft or human exploration activity, we investigated the resistance of Sphingomonas desiccabilis to brines that simulate the composition of martian aqueous environments. S. desiccabilis is a desiccation-resistant, biofilm-forming microbe found in desert crusts. The viability of cells in both planktonic and biofilm forms was measured after exposure to simulated martian brines. Planktonic cells showed a loss of viability over the course of several hours in almost all of the seven brines tested. Biofilms conferred greater resistance to all the brines, including those with low water activity and pH, but even cells in biofilms showed a complete loss of viability in <6 h in the harsher brines and in <2 days in the less harsh brines. One brine, however, allowed the microbes to maintain viability over several days, despite having a water activity and pH lower and ionic strength higher than brines that reduced viability over the same timescales, suggesting important ion-specific effects. These data show that biofilm-forming cells have a greater capacity to resist martian aqueous extremes, but that evaporative or deliquescent brines are likely to be destructive to many organisms over relatively short timescales, with implications for the habitability of Mars and for micro-organisms dispersed by robotic or human explorers.
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Affiliation(s)
- Adam H. Stevens
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Delma Childers
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
- Aberdeen Fungal Group, Institute of Medical Sciences, MRC Centre for Medical Mycology at the University of Aberdeen, Aberdeen, United Kingdom
| | - Mark Fox-Powell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
- School of Earth and Environmental Sciences, University of St. Andrews, St. Andrews, United Kingdom
| | - Natasha Nicholson
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Elisha Jhoti
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Charles S. Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
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40
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Lee CJD, McMullan PE, O'Kane CJ, Stevenson A, Santos IC, Roy C, Ghosh W, Mancinelli RL, Mormile MR, McMullan G, Banciu HL, Fares MA, Benison KC, Oren A, Dyall-Smith ML, Hallsworth JE. NaCl-saturated brines are thermodynamically moderate, rather than extreme, microbial habitats. FEMS Microbiol Rev 2018; 42:672-693. [PMID: 29893835 DOI: 10.1093/femsre/fuy026] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 06/08/2018] [Indexed: 11/12/2022] Open
Abstract
NaCl-saturated brines such as saltern crystalliser ponds, inland salt lakes, deep-sea brines and liquids-of-deliquescence on halite are commonly regarded as a paradigm for the limit of life on Earth. There are, however, other habitats that are thermodynamically more extreme. Typically, NaCl-saturated environments contain all domains of life and perform complete biogeochemical cycling. Despite their reduced water activity, ∼0.755 at 5 M NaCl, some halophiles belonging to the Archaea and Bacteria exhibit optimum growth/metabolism in these brines. Furthermore, the recognised water-activity limit for microbial function, ∼0.585 for some strains of fungi, lies far below 0.755. Other biophysical constraints on the microbial biosphere (temperatures of >121°C; pH > 12; and high chaotropicity; e.g. ethanol at >18.9% w/v (24% v/v) and MgCl2 at >3.03 M) can prevent any cellular metabolism or ecosystem function. By contrast, NaCl-saturated environments contain biomass-dense, metabolically diverse, highly active and complex microbial ecosystems; and this underscores their moderate character. Here, we survey the evidence that NaCl-saturated brines are biologically permissive, fertile habitats that are thermodynamically mid-range rather than extreme. Indeed, were NaCl sufficiently soluble, some halophiles might grow at concentrations of up to 8 M. It may be that the finite solubility of NaCl has stabilised the genetic composition of halophile populations and limited the action of natural selection in driving halophile evolution towards greater xerophilicity. Further implications are considered for the origin(s) of life and other aspects of astrobiology.
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Affiliation(s)
- Callum J D Lee
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Phillip E McMullan
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Callum J O'Kane
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Andrew Stevenson
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Inês C Santos
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX 76019, USA
| | - Chayan Roy
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata, 700054, India
| | - Wriddhiman Ghosh
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata, 700054, India
| | - Rocco L Mancinelli
- BAER Institute, Mail Stop 239-4, NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Melanie R Mormile
- Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO 65401, USA
| | - Geoffrey McMullan
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Horia L Banciu
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babes-Bolyai University, 400006 Cluj-Napoca, Romania
| | - Mario A Fares
- Department of Abiotic Stress, Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, Valencia 46022, Spain.,Institute for Integrative Systems Biology (I2SysBio), Consejo Superior de Investigaciones Científicas-Universitat de Valencia (CSIC-UV), Valencia, 46980, Spain.,Department of Genetics, Smurfit Institute of Genetics, University of Dublin, Trinity College, Dublin 2, Dublin, Ireland
| | - Kathleen C Benison
- Department of Geology and Geography, West Virginia University, Morgantown, WV 26506-6300, USA
| | - Aharon Oren
- Department of Plant & Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat-Ram, Jerusalem 9190401, Israel
| | - Mike L Dyall-Smith
- Faculty of Veterinary and Agricultural Science, The University of Melbourne, Parkville, VIC 3010, Australia
| | - John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
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41
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McGenity TJ. 2038 – When microbes rule the Earth. Environ Microbiol 2018; 20:4213-4220. [DOI: 10.1111/1462-2920.14449] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 10/11/2018] [Indexed: 01/19/2023]
Affiliation(s)
- Terry J. McGenity
- School of Biological SciencesUniversity of Essex Colchester United Kingdom
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42
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Curtis-Harper E, Pearson VK, Summers S, Bridges JC, Schwenzer SP, Olsson-Francis K. The Microbial Community of a Terrestrial Anoxic Inter-Tidal Zone: A Model for Laboratory-Based Studies of Potentially Habitable Ancient Lacustrine Systems on Mars. Microorganisms 2018; 6:microorganisms6030061. [PMID: 29966361 PMCID: PMC6165429 DOI: 10.3390/microorganisms6030061] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 06/18/2018] [Accepted: 06/21/2018] [Indexed: 11/16/2022] Open
Abstract
Evidence indicates that Gale crater on Mars harboured a fluvio-lacustrine environment that was subjected to physio-chemical variations such as changes in redox conditions and evaporation with salinity changes, over time. Microbial communities from terrestrial environmental analogues sites are important for studying such potential habitability environments on early Mars, especially in laboratory-based simulation experiments. Traditionally, such studies have predominantly focused on microorganisms from extreme terrestrial environments. These are applicable to a range of Martian environments; however, they lack relevance to the lacustrine systems. In this study, we characterise an anoxic inter-tidal zone as a terrestrial analogue for the Gale crater lake system according to its chemical and physical properties, and its microbiological community. The sub-surface inter-tidal environment of the River Dee estuary, United Kingdom (53°21′15.40″ N, 3°10′24.95″ W) was selected and compared with available data from Early Hesperian-time Gale crater, and temperature, redox, and pH were similar. Compared to subsurface ‘groundwater’-type fluids invoked for the Gale subsurface, salinity was higher at the River Dee site, which are more comparable to increases in salinity that likely occurred as the Gale crater lake evolved. Similarities in clay abundance indicated similar access to, specifically, the bio-essential elements Mg, Fe and K. The River Dee microbial community consisted of taxa that were known to have members that could utilise chemolithoautotrophic and chemoorganoheterotrophic metabolism and such a mixed metabolic capability would potentially have been feasible on Mars. Microorganisms isolated from the site were able to grow under environment conditions that, based on mineralogical data, were similar to that of the Gale crater’s aqueous environment at Yellowknife Bay. Thus, the results from this study suggest that the microbial community from an anoxic inter-tidal zone is a plausible terrestrial analogue for studying habitability of fluvio-lacustrine systems on early Mars, using laboratory-based simulation experiments.
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Affiliation(s)
- Elliot Curtis-Harper
- Faculty of Science, Technology, Engineering and Mathematics, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK.
| | - Victoria K Pearson
- Faculty of Science, Technology, Engineering and Mathematics, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK.
| | - Stephen Summers
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore, Singapore.
| | - John C Bridges
- Space Research Centre, Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK.
| | - Susanne P Schwenzer
- Faculty of Science, Technology, Engineering and Mathematics, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK.
| | - Karen Olsson-Francis
- Faculty of Science, Technology, Engineering and Mathematics, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK.
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43
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Fox-Powell MG, Cockell CS. Building a Geochemical View of Microbial Salt Tolerance: Halophilic Adaptation of Marinococcus in a Natural Magnesium Sulfate Brine. Front Microbiol 2018; 9:739. [PMID: 29713317 PMCID: PMC5911959 DOI: 10.3389/fmicb.2018.00739] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 03/29/2018] [Indexed: 11/13/2022] Open
Abstract
Current knowledge of life in hypersaline habitats is mostly limited to sodium and chloride-dominated environments. This narrow compositional window does not reflect the diversity of brine environments that exist naturally on Earth and other planetary bodies. Understanding the limits of the microbial biosphere and predicting extraterrestrial habitability demands a systematic effort to characterize ionic specificities of organisms from a representative range of saline habitats. Here, we investigated a strain of Marinococcus isolated from the magnesium and sulfate-dominated Basque Lakes (British Columbia, Canada). This organism was the sole isolate obtained after exposure to exceptionally high levels of Mg2+ and SO42- ions (2.369 and 2.840 M, respectively), and grew at extremes of ionic strength not normally encountered in Na+/Cl- brines (12.141 mol liter-1). Its association at the 16S rDNA level with bacterial halophiles suggests that ancestral halophily has allowed it to adapt to a different saline habitat. Growth was demonstrated in media dominated by NaCl, Na2SO4, MgCl2, and MgSO4, yet despite this plasticity the strain was still restricted; requiring either Na+ or Cl- to maintain short doubling times. Water activity could not explain growth rate differences between media, demonstrating the importance of ionic composition for dictating microbial growth windows. A new framework for understanding growth in brines is required, that accounts for the geochemical history of brines as well as the various stresses that ions impose on microbes. Studies such as this are required to gain a truly universal understanding of the limits of biological ion tolerance.
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Affiliation(s)
- Mark G Fox-Powell
- UK Centre for Astrobiology, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, United Kingdom.,School of Earth and Environmental Sciences, University of St Andrews, St Andrews, United Kingdom
| | - Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, United Kingdom
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44
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Price A, Pearson VK, Schwenzer SP, Miot J, Olsson-Francis K. Nitrate-Dependent Iron Oxidation: A Potential Mars Metabolism. Front Microbiol 2018; 9:513. [PMID: 29616015 PMCID: PMC5869265 DOI: 10.3389/fmicb.2018.00513] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 03/06/2018] [Indexed: 11/13/2022] Open
Abstract
This work considers the hypothetical viability of microbial nitrate-dependent Fe2+ oxidation (NDFO) for supporting simple life in the context of the early Mars environment. This draws on knowledge built up over several decades of remote and in situ observation, as well as recent discoveries that have shaped current understanding of early Mars. Our current understanding is that certain early martian environments fulfill several of the key requirements for microbes with NDFO metabolism. First, abundant Fe2+ has been identified on Mars and provides evidence of an accessible electron donor; evidence of anoxia suggests that abiotic Fe2+ oxidation by molecular oxygen would not have interfered and competed with microbial iron metabolism in these environments. Second, nitrate, which can be used by some iron oxidizing microorganisms as an electron acceptor, has also been confirmed in modern aeolian and ancient sediment deposits on Mars. In addition to redox substrates, reservoirs of both organic and inorganic carbon are available for biosynthesis, and geochemical evidence suggests that lacustrine systems during the hydrologically active Noachian period (4.1-3.7 Ga) match the circumneutral pH requirements of nitrate-dependent iron-oxidizing microorganisms. As well as potentially acting as a primary producer in early martian lakes and fluvial systems, the light-independent nature of NDFO suggests that such microbes could have persisted in sub-surface aquifers long after the desiccation of the surface, provided that adequate carbon and nitrates sources were prevalent. Traces of NDFO microorganisms may be preserved in the rock record by biomineralization and cellular encrustation in zones of high Fe2+ concentrations. These processes could produce morphological biosignatures, preserve distinctive Fe-isotope variation patterns, and enhance preservation of biological organic compounds. Such biosignatures could be detectable by future missions to Mars with appropriate instrumentation.
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Affiliation(s)
- Alex Price
- Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Victoria K. Pearson
- Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Susanne P. Schwenzer
- Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Jennyfer Miot
- CNRS, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Muséum National d’Histoire Naturelle, Université Pierre et Marie Curie – Sorbonne Universités, UMR 7590, Paris, France
| | - Karen Olsson-Francis
- Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
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Schwendner P, Bohmeier M, Rettberg P, Beblo-Vranesevic K, Gaboyer F, Moissl-Eichinger C, Perras AK, Vannier P, Marteinsson VT, Garcia-Descalzo L, Gómez F, Malki M, Amils R, Westall F, Riedo A, Monaghan EP, Ehrenfreund P, Cabezas P, Walter N, Cockell C. Beyond Chloride Brines: Variable Metabolomic Responses in the Anaerobic Organism Yersinia intermedia MASE-LG-1 to NaCl and MgSO 4 at Identical Water Activity. Front Microbiol 2018; 9:335. [PMID: 29535699 PMCID: PMC5835128 DOI: 10.3389/fmicb.2018.00335] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 02/12/2018] [Indexed: 11/18/2022] Open
Abstract
Growth in sodium chloride (NaCl) is known to induce stress in non-halophilic microorganisms leading to effects on the microbial metabolism and cell structure. Microorganisms have evolved a number of adaptations, both structural and metabolic, to counteract osmotic stress. These strategies are well-understood for organisms in NaCl-rich brines such as the accumulation of certain organic solutes (known as either compatible solutes or osmolytes). Less well studied are responses to ionic environments such as sulfate-rich brines which are prevalent on Earth but can also be found on Mars. In this paper, we investigated the global metabolic response of the anaerobic bacterium Yersinia intermedia MASE-LG-1 to osmotic salt stress induced by either magnesium sulfate (MgSO4) or NaCl at the same water activity (0.975). Using a non-targeted mass spectrometry approach, the intensity of hundreds of metabolites was measured. The compatible solutes L-asparagine and sucrose were found to be increased in both MgSO4 and NaCl compared to the control sample, suggesting a similar osmotic response to different ionic environments. We were able to demonstrate that Yersinia intermedia MASE-LG-1 accumulated a range of other compatible solutes. However, we also found the global metabolic responses, especially with regard to amino acid metabolism and carbohydrate metabolism, to be salt-specific, thus, suggesting ion-specific regulation of specific metabolic pathways.
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Affiliation(s)
- Petra Schwendner
- School of Physics and Astronomy, UK Center for Astrobiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Maria Bohmeier
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
| | - Petra Rettberg
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
| | - Kristina Beblo-Vranesevic
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
| | - Frédéric Gaboyer
- Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique, Orléans, France
| | - Christine Moissl-Eichinger
- Department of Internal Medicine, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Alexandra K. Perras
- Department of Internal Medicine, Medical University of Graz, Graz, Austria
- Department of Microbiology and Archaea, University of Regensburg, Regensburg, Germany
| | | | - Viggó T. Marteinsson
- MATIS - Prokaria, Reykjavík, Iceland
- Faculty of Food Science and Nutrition, University of Iceland, Reykjavik, Iceland
| | | | - Felipe Gómez
- Instituto Nacional de Técnica Aeroespacial - Centro de Astrobiología, Madrid, Spain
| | - Moustafa Malki
- Centro de Biología Molecular Severo Ochoa (CBMSO, CSIC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
| | - Ricardo Amils
- Centro de Biología Molecular Severo Ochoa (CBMSO, CSIC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
| | - Frances Westall
- Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique, Orléans, France
| | - Andreas Riedo
- Leiden Observatory, Universiteit Leiden, Leiden, Netherlands
| | | | - Pascale Ehrenfreund
- Leiden Observatory, Universiteit Leiden, Leiden, Netherlands
- Space Policy Institute, George Washington University, Washington, DC, United States
| | - Patricia Cabezas
- Space Policy Institute, George Washington University, Washington, DC, United States
- European Science Foundation, Strasbourg, France
| | - Nicolas Walter
- Space Policy Institute, George Washington University, Washington, DC, United States
- European Science Foundation, Strasbourg, France
| | - Charles Cockell
- School of Physics and Astronomy, UK Center for Astrobiology, University of Edinburgh, Edinburgh, United Kingdom
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Fairén AG, Parro V, Schulze-Makuch D, Whyte L. Is Searching for Martian Life a Priority for the Mars Community? ASTROBIOLOGY 2018; 18:101-107. [PMID: 29359967 PMCID: PMC5820680 DOI: 10.1089/ast.2017.1772] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 11/02/2017] [Indexed: 06/07/2023]
Affiliation(s)
- Alberto G. Fairén
- Centro de Astrobiología (CSIC-INTA), Madrid, Spain
- Department of Astronomy, Cornell University, Ithaca, New York, USA
| | - Victor Parro
- Centro de Astrobiología (CSIC-INTA), Madrid, Spain
| | - Dirk Schulze-Makuch
- Center of Astronomy and Astrophysics, Technical University Berlin, Berlin, Germany
- School of the Environment, Washington State University, Pullman, Washington, USA
| | - Lyle Whyte
- Department of Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, Canada
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Cockell CS, Biller B, Bryce C, Cousins C, Direito S, Forgan D, Fox-Powell M, Harrison J, Landenmark H, Nixon S, Payler SJ, Rice K, Samuels T, Schwendner P, Stevens A, Nicholson N, Wadsworth J. The UK Centre for Astrobiology: A Virtual Astrobiology Centre. Accomplishments and Lessons Learned, 2011-2016. ASTROBIOLOGY 2018; 18:224-243. [PMID: 29377716 PMCID: PMC5820684 DOI: 10.1089/ast.2017.1713] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 08/16/2017] [Indexed: 05/17/2023]
Abstract
The UK Centre for Astrobiology (UKCA) was set up in 2011 as a virtual center to contribute to astrobiology research, education, and outreach. After 5 years, we describe this center and its work in each of these areas. Its research has focused on studying life in extreme environments, the limits of life on Earth, and implications for habitability elsewhere. Among its research infrastructure projects, UKCA has assembled an underground astrobiology laboratory that has hosted a deep subsurface planetary analog program, and it has developed new flow-through systems to study extraterrestrial aqueous environments. UKCA has used this research backdrop to develop education programs in astrobiology, including a massive open online course in astrobiology that has attracted over 120,000 students, a teacher training program, and an initiative to take astrobiology into prisons. In this paper, we review these activities and others with a particular focus on providing lessons to others who may consider setting up an astrobiology center, institute, or science facility. We discuss experience in integrating astrobiology research into teaching and education activities. Key Words: Astrobiology-Centre-Education-Subsurface-Analog research. Astrobiology 18, 224-243.
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Affiliation(s)
- Charles S. Cockell
- UK Centre for Astrobiology, Scottish Universities Physics Alliance, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, UK
| | - Beth Biller
- UK Centre for Astrobiology, Scottish Universities Physics Alliance, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, UK
| | - Casey Bryce
- Eberhard Karls Universitaet Tuebingen, Center for Applied Geoscience (ZAG), Geomicrobiology, Tuebingen, Germany
| | - Claire Cousins
- Centre for Exoplanet Science, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, UK
| | - Susana Direito
- UK Centre for Astrobiology, Scottish Universities Physics Alliance, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, UK
| | - Duncan Forgan
- Centre for Exoplanet Science, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, UK
| | - Mark Fox-Powell
- UK Centre for Astrobiology, Scottish Universities Physics Alliance, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, UK
| | - Jesse Harrison
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Research Network “Chemistry Meets Microbiology”, University of Vienna, Vienna, Austria
| | - Hanna Landenmark
- UK Centre for Astrobiology, Scottish Universities Physics Alliance, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, UK
| | - Sophie Nixon
- Geomicrobiology Research Group, School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester, UK
| | - Samuel J. Payler
- UK Centre for Astrobiology, Scottish Universities Physics Alliance, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, UK
| | - Ken Rice
- UK Centre for Astrobiology, Scottish Universities Physics Alliance, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, UK
| | - Toby Samuels
- UK Centre for Astrobiology, Scottish Universities Physics Alliance, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, UK
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Petra Schwendner
- UK Centre for Astrobiology, Scottish Universities Physics Alliance, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, UK
| | - Adam Stevens
- UK Centre for Astrobiology, Scottish Universities Physics Alliance, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, UK
| | - Natasha Nicholson
- UK Centre for Astrobiology, Scottish Universities Physics Alliance, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, UK
| | - Jennifer Wadsworth
- UK Centre for Astrobiology, Scottish Universities Physics Alliance, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, UK
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50
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Pontefract A, Zhu TF, Walker VK, Hepburn H, Lui C, Zuber MT, Ruvkun G, Carr CE. Microbial Diversity in a Hypersaline Sulfate Lake: A Terrestrial Analog of Ancient Mars. Front Microbiol 2017; 8:1819. [PMID: 29018418 PMCID: PMC5623196 DOI: 10.3389/fmicb.2017.01819] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 09/06/2017] [Indexed: 11/13/2022] Open
Abstract
Life can persist under severe osmotic stress and low water activity in hypersaline environments. On Mars, evidence for the past presence of saline bodies of water is prevalent and resulted in the widespread deposition of sulfate and chloride salts. Here we investigate Spotted Lake (British Columbia, Canada), a hypersaline lake with extreme (>3 M) levels of sulfate salts as an exemplar of the conditions thought to be associated with ancient Mars. We provide the first characterization of microbial structure in Spotted Lake sediments through metagenomic sequencing, and report a bacteria-dominated community with abundant Proteobacteria, Firmicutes, and Bacteroidetes, as well as diverse extremophiles. Microbial abundance and functional comparisons reveal similarities to Ace Lake, a meromictic Antarctic lake with anoxic and sulfidic bottom waters. Our analysis suggests that hypersaline-associated species occupy niches characterized foremost by differential abundance of Archaea, uncharacterized Bacteria, and Cyanobacteria. Potential biosignatures in this environment are discussed, specifically the likelihood of a strong sulfur isotopic fractionation record within the sediments due to the presence of sulfate reducing bacteria. With its high sulfate levels and seasonal freeze-thaw cycles, Spotted Lake is an analog for ancient paleolakes on Mars in which sulfate salt deposits may have offered periodically habitable environments, and could have concentrated and preserved organic materials or their biomarkers over geologic time.
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Affiliation(s)
- Alexandra Pontefract
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States.,Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, United States
| | - Ting F Zhu
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
| | | | - Holli Hepburn
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, United States
| | - Clarissa Lui
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Maria T Zuber
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Gary Ruvkun
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, United States.,Department of Genetics, Harvard Medical School, Boston, MA, United States
| | - Christopher E Carr
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States.,Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, United States
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