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Caro-Astorga J, Meyerowitz JT, Stork DA, Nattermann U, Piszkiewicz S, Vimercati L, Schwendner P, Hocher A, Cockell C, DeBenedictis E. Polyextremophile engineering: a review of organisms that push the limits of life. Front Microbiol 2024; 15:1341701. [PMID: 38903795 PMCID: PMC11188471 DOI: 10.3389/fmicb.2024.1341701] [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: 11/20/2023] [Accepted: 05/16/2024] [Indexed: 06/22/2024] Open
Abstract
Nature exhibits an enormous diversity of organisms that thrive in extreme environments. From snow algae that reproduce at sub-zero temperatures to radiotrophic fungi that thrive in nuclear radiation at Chernobyl, extreme organisms raise many questions about the limits of life. Is there any environment where life could not "find a way"? Although many individual extremophilic organisms have been identified and studied, there remain outstanding questions about the limits of life and the extent to which extreme properties can be enhanced, combined or transferred to new organisms. In this review, we compile the current knowledge on the bioengineering of extremophile microbes. We summarize what is known about the basic mechanisms of extreme adaptations, compile synthetic biology's efforts to engineer extremophile organisms beyond what is found in nature, and highlight which adaptations can be combined. The basic science of extremophiles can be applied to engineered organisms tailored to specific biomanufacturing needs, such as growth in high temperatures or in the presence of unusual solvents.
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Affiliation(s)
| | | | - Devon A. Stork
- Pioneer Research Laboratories, San Francisco, CA, United States
| | - Una Nattermann
- Pioneer Research Laboratories, San Francisco, CA, United States
| | | | - Lara Vimercati
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, United States
| | | | - Antoine Hocher
- London Institute of Medical Sciences, London, United Kingdom
| | - Charles Cockell
- UK Centre for Astrobiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Erika DeBenedictis
- The Francis Crick Institute, London, United Kingdom
- Pioneer Research Laboratories, San Francisco, CA, United States
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2
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Jiang CZ, Rimmer PB, Lozano GG, Tosca NJ, Kufner CL, Sasselov DD, Thompson SJ. Iron-sulfur chemistry can explain the ultraviolet absorber in the clouds of Venus. SCIENCE ADVANCES 2024; 10:eadg8826. [PMID: 38170780 PMCID: PMC10776003 DOI: 10.1126/sciadv.adg8826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 12/01/2023] [Indexed: 01/05/2024]
Abstract
The clouds of Venus are believed to be composed of sulfuric acid (H2SO4) and minor constituents including iron-bearing compounds, and their respective concentrations vary with height in the thick Venusian atmosphere. This study experimentally investigates possible iron-bearing mineral phases that are stable under the unique conditions within Venusian clouds. Our results demonstrate that ferric iron can react with sulfuric acid to form two mineral phases: rhomboclase [(H5O2)Fe(SO4)2·3H2O] and acid ferric sulfate [(H3O)Fe(SO4)2]. A combination of these two mineral phases and dissolved Fe3+ in varying concentrations of sulfuric acid are shown to be good candidates for explaining the 200- to 300-nm and 300- to 500-nm features of the reported unknown UV absorber. We, therefore, hypothesize a rich and largely unexplored heterogeneous chemistry in the cloud droplets of Venus that has a large effect on the optical properties of the clouds and the behavior of trace gas species throughout Venus's atmosphere.
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Affiliation(s)
- Clancy Zhijian Jiang
- Department of Earth Sciences, University of Cambridge, Downing St., Cambridge CB2 3EQ, UK
| | - Paul B. Rimmer
- Cavendish Laboratory, University of Cambridge, JJ Thomson Ave, Cambridge CB3 0HE, UK
| | - Gabriella G. Lozano
- Harvard-Smithsonian Center for Astrophysics, Harvard University, 60 Garden Street, Cambridge, MA 02138, USA
| | - Nicholas J. Tosca
- Department of Earth Sciences, University of Cambridge, Downing St., Cambridge CB2 3EQ, UK
| | - Corinna L. Kufner
- Harvard-Smithsonian Center for Astrophysics, Harvard University, 60 Garden Street, Cambridge, MA 02138, USA
| | - Dimitar D. Sasselov
- Harvard-Smithsonian Center for Astrophysics, Harvard University, 60 Garden Street, Cambridge, MA 02138, USA
| | - Samantha J. Thompson
- Cavendish Laboratory, University of Cambridge, JJ Thomson Ave, Cambridge CB3 0HE, UK
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3
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Chen C, Yi R, Igisu M, Sakaguchi C, Afrin R, Potiszil C, Kunihiro T, Kobayashi K, Nakamura E, Ueno Y, Antunes A, Wang A, Chandru K, Hao J, Jia TZ. Spectroscopic and Biophysical Methods to Determine Differential Salt-Uptake by Primitive Membraneless Polyester Microdroplets. SMALL METHODS 2023; 7:e2300119. [PMID: 37203261 DOI: 10.1002/smtd.202300119] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 04/23/2023] [Indexed: 05/20/2023]
Abstract
α-Hydroxy acids are prebiotic monomers that undergo dehydration synthesis to form polyester gels, which assemble into membraneless microdroplets upon aqueous rehydration. These microdroplets are proposed as protocells that can segregate and compartmentalize primitive molecules/reactions. Different primitive aqueous environments with a variety of salts could have hosted chemistries that formed polyester microdroplets. These salts could be essential cofactors of compartmentalized prebiotic reactions or even directly affect protocell structure. However, fully understanding polyester-salt interactions remains elusive, partially due to technical challenges of quantitative measurements in condensed phases. Here, spectroscopic and biophysical methods are applied to analyze salt uptake by polyester microdroplets. Inductively coupled plasma mass spectrometry is applied to measure the cation concentration within polyester microdroplets after addition of chloride salts. Combined with methods to determine the effects of salt uptake on droplet turbidity, size, surface potential and internal water distribution, it was observed that polyester microdroplets can selectively partition salt cations, leading to differential microdroplet coalescence due to ionic screening effects reducing electrostatic repulsion forces between microdroplets. Through applying existing techniques to novel analyses related to primitive compartment chemistry and biophysics, this study suggests that even minor differences in analyte uptake can lead to significant protocellular structural change.
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Affiliation(s)
- Chen Chen
- Earth-Life Science Institute, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8550, Japan
| | - Ruiqin Yi
- Earth-Life Science Institute, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8550, Japan
| | - Motoko Igisu
- Institute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, 237-0061, Japan
| | - Chie Sakaguchi
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Misasa, Tottori, 682-0193, Japan
| | - Rehana Afrin
- Earth-Life Science Institute, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8550, Japan
| | - Christian Potiszil
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Misasa, Tottori, 682-0193, Japan
| | - Tak Kunihiro
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Misasa, Tottori, 682-0193, Japan
| | - Katsura Kobayashi
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Misasa, Tottori, 682-0193, Japan
| | - Eizo Nakamura
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Misasa, Tottori, 682-0193, Japan
| | - Yuichiro Ueno
- Earth-Life Science Institute, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8550, Japan
- Institute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, 237-0061, Japan
- Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8551, Japan
| | - André Antunes
- State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology (MUST), Taipa, Macau, SAR, China
- Blue Marble Space Institute of Science, Seattle, WA, 98104, USA
| | - Anna Wang
- School of Chemistry, UNSW Sydney, Sydney, NSW, 2052, Australia
- Australian Centre for Astrobiology, UNSW Sydney, Sydney, NSW, 2052, Australia
- RNA Institute, UNSW Sydney, Sydney, NSW, 2052, Australia
- ARC Centre of Excellence for Synthetic Biology, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Kuhan Chandru
- Space Science Center (ANGKASA), Institute of Climate Change, National University of Malaysia, Selangor, 43650, Malaysia
| | - Jihua Hao
- Blue Marble Space Institute of Science, Seattle, WA, 98104, USA
- Deep Space Exploration Laboratory/CAS Laboratory of Crust-Mantle Materials and Environments, University of Science and Technology of China, Hefei, 230026, China
| | - Tony Z Jia
- Earth-Life Science Institute, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8550, Japan
- Blue Marble Space Institute of Science, Seattle, WA, 98104, USA
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Moors H, De Craen M, Smolders C, Provoost A, Leys N. The waterbodies of the halo-volcanic Dallol complex: earth analogs to guide us, where to look for life in the universe. Front Microbiol 2023; 14:1134760. [PMID: 37520359 PMCID: PMC10382021 DOI: 10.3389/fmicb.2023.1134760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 06/30/2023] [Indexed: 08/01/2023] Open
Abstract
Microbes are the Earth life forms that have the highest degree of adaptability to survive, live, or even proliferate in very hostile environments. It is even stated that microbes can cope with any extreme physico-chemical condition and are, therefore, omnipresent all over the Earth: on all the continents, inside its crust and in all its waterbodies. However, our study suggests that there exists areas and even water rich environments on Earth where no life is possible. To support the fact that water rich environments can be lifeless, we performed an extensive survey of 10 different hyper extreme waterbodies of the halo-volcanic Dallol complex (Danakil depression, Ethiopia, Horn of Africa). In our study, we combined physico-chemical analyses, mineralogical investigations, XRD and SEM-EDX analyses, ATP measurements, 16S rDNA microbial community determinations, and microbial culturing techniques. According to our findings, we suggest that the individual physico-chemical parameters, water activity, and kosmo-chaotropicity, are the two most important factors that determine whether an environment is lifeless or capable of hosting specific extreme lifeforms. Besides, waterbodies that contained saturated levels of sodium chloride but at the same time possessed extreme low pH values, appeared to be poly-extreme environments in which no life could be detected. However, we clearly discovered a low diversity microbial community in waterbodies that were fully saturated with sodium chloride and only mildly acidic. Our results can be beneficial to more precisely classify whole or certain areas of planetary bodies, including water rich environments, as either potentially habitable or factual uninhabitable environments.
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Affiliation(s)
- Hugo Moors
- Microbiology Unit, Belgian Nuclear Research Center (SCK CEN), Nuclear Medical Applications Institute (NMA), Mol, Belgium
| | - Mieke De Craen
- Research and Development Disposal, Belgian Nuclear Research Center (SCK CEN), Waste and Disposal (W&D), Mol, Belgium
- European Underground Research Infrastructure for Disposal of Nuclear Waste in Clay Environment, EIG EURIDICE, Mol, Belgium
| | - Carla Smolders
- Microbiology Unit, Belgian Nuclear Research Center (SCK CEN), Nuclear Medical Applications Institute (NMA), Mol, Belgium
| | - Ann Provoost
- Microbiology Unit, Belgian Nuclear Research Center (SCK CEN), Nuclear Medical Applications Institute (NMA), Mol, Belgium
| | - Natalie Leys
- Microbiology Unit, Belgian Nuclear Research Center (SCK CEN), Nuclear Medical Applications Institute (NMA), Mol, Belgium
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A miniaturized bionic ocean-battery mimicking the structure of marine microbial ecosystems. Nat Commun 2022; 13:5608. [PMID: 36153325 PMCID: PMC9509365 DOI: 10.1038/s41467-022-33358-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 09/14/2022] [Indexed: 11/08/2022] Open
Abstract
AbstractMarine microbial ecosystems can be viewed as a huge ocean-battery charged by solar energy. It provides a model for fabricating bio-solar cell, a bioelectrochemical system that converts light into electricity. Here, we fabricate a bio-solar cell consisting of a four-species microbial community by mimicking the ecological structure of marine microbial ecosystems. We demonstrate such ecological structure consisting of primary producer, primary degrader, and ultimate consumers is essential for achieving high power density and stability. Furthermore, the four-species microbial community is assembled into a spatial-temporally compacted cell using conductive hydrogel as a sediment-like anaerobic matrix, forming a miniaturized bionic ocean-battery. This battery directly converts light into electricity with a maximum power of 380 μW and stably operates for over one month. Reproducing the photoelectric conversion function of marine microbial ecosystems in this bionic battery overcomes the sluggish and network-like electron transfer, showing the biotechnological potential of synthetic microbial ecology.
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6
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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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7
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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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8
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Internet of Spacecraft for Multi-Planetary Defense and Prosperity. SIGNALS 2022. [DOI: 10.3390/signals3030026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Recent years have seen unprecedentedly fast-growing prosperity in the commercial space industry. Several privately funded aerospace manufacturers, such as Space Exploration Technologies Corporation (SpaceX) and Blue Origin have transformed what we used to know about this capital-intense industry and gradually reshaped the future of human civilization. As private spaceflight and multi-planetary immigration gradually become realities from science fiction (sci-fi) and theory, both opportunities and challenges will be presented. In this article, we first review the progress in space exploration and the underlying space technologies. Next, we revisit the K-Pg extinction event and the Chelyabinsk event and predict extra-terrestrialization, terraformation, and planetary defense, including the emerging near-Earth object (NEO) observation and NEO impact avoidance technologies and strategies. Furthermore, a framework for the Solar Communication and Defense Networks (SCADN) with advanced algorithms and high efficacy is proposed to enable an Internet of distributed deep-space sensing, communications, and defense to cope with disastrous incidents such as asteroid/comet impacts. Furthermore, perspectives on the legislation, management, and supervision of founding the proposed SCADN are also discussed in depth.
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9
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Fernández-Remolar DC, Carrizo D, Harir M, Huang T, Amils R, Schmitt-Kopplin P, Sánchez-García L, Gomez-Ortiz D, Malmberg P. Unveiling microbial preservation under hyperacidic and oxidizing conditions in the Oligocene Rio Tinto deposit. Sci Rep 2021; 11:21543. [PMID: 34728655 PMCID: PMC8563943 DOI: 10.1038/s41598-021-00730-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 10/11/2021] [Indexed: 11/22/2022] Open
Abstract
The preservation of biosignatures on Mars is largely associated with extensive deposits of clays formed under mild early Noachian conditions (> 3.9 Ga). They were followed by widespread precipitation of acidic sulfates considered adverse for biomolecule preservation. In this paper, an exhaustive mass spectrometry investigation of ferric subsurface materials in the Rio Tinto gossan deposit (~ 25 Ma) provides evidence of well-preserved molecular biosignatures under oxidative and acidic conditions. Time of flight secondary ion mass spectrometry (ToF–SIMS) analysis shows a direct association between physical-templating biological structures and molecular biosignatures. This relation implies that the quality of molecular preservation is exceptional and provides information on microbial life formerly operating in the shallow regions of the Rio Tinto subsurface. Consequently, low-pH oxidative environments on Mars could also record molecular information about ancient life in the same way as the Noachian clay-rich deposits.
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Affiliation(s)
- David C Fernández-Remolar
- CEA, CNRS, IBS, Metalloproteins Unit, Université Grenoble Alpes, 38000, Grenoble, France. .,State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau, 999078, PR China. .,CNSA Macau Center for Space Exploration and Science, Macau, 999078, PR China.
| | | | - Mourad Harir
- Research Unit Analytical Biogeochemistry, Helmholtz Zentrum München, Neuherberg, Germany
| | - Ting Huang
- State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau, China
| | - Ricardo Amils
- Centro de Astrobiología (INTA-CSIC), Madrid, Spain.,Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Philippe Schmitt-Kopplin
- Research Unit Analytical Biogeochemistry, Helmholtz Zentrum München, Neuherberg, Germany.,Chair of Analytical Food Chemistry, Technical University Munich, 85354, Freising-Weihenstephan, Germany
| | | | - David Gomez-Ortiz
- ESCET-Área de Geología, Universidad Rey Juan Carlos, 28933, Móstoles, Madrid, Spain
| | - Per Malmberg
- Chemistry and Chemical Engineering, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden
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10
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Baucon A, Neto de Carvalho C, Briguglio A, Piazza M, Felletti F. A predictive model for the ichnological suitability of the Jezero crater, Mars: searching for fossilized traces of life-substrate interactions in the 2020 Rover Mission Landing Site. PeerJ 2021; 9:e11784. [PMID: 34631304 PMCID: PMC8466086 DOI: 10.7717/peerj.11784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 06/24/2021] [Indexed: 11/20/2022] Open
Abstract
Ichnofossils, the fossilized products of life-substrate interactions, are among the most abundant biosignatures on Earth and therefore they may provide scientific evidence of potential life that may have existed on Mars. Ichnofossils offer unique advantages in the search for extraterrestrial life, including the fact that they are resilient to processes that obliterate other evidence for past life, such as body fossils, as well as chemical and isotopic biosignatures. The goal of this paper is evaluating the suitability of the Mars 2020 Landing Site for ichnofossils. To this goal, we apply palaeontological predictive modelling, a technique used to forecast the location of fossil sites in uninvestigated areas on Earth. Accordingly, a geographic information system (GIS) of the landing site is developed. Each layer of the GIS maps the suitability for one or more ichnofossil types (bioturbation, bioerosion, biostratification structures) based on an assessment of a single attribute (suitability factor) of the Martian environment. Suitability criteria have been selected among the environmental attributes that control ichnofossil abundance and preservation in 18 reference sites on Earth. The goal of this research is delivered through three predictive maps showing which areas of the Mars 2020 Landing Site are more likely to preserve potential ichnofossils. On the basis of these maps, an ichnological strategy for the Perseverance rover is identified, indicating (1) 10 sites on Mars with high suitability for bioturbation, bioerosion and biostratification ichnofossils, (2) the ichnofossil types, if any, that are more likely to be present at each site, (3) the most efficient observation strategy for detecting eventual ichnofossils. The predictive maps and the ichnological strategy can be easily integrated in the existing plans for the exploration of the Jezero crater, realizing benefits in life-search efficiency and cost-reduction.
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Affiliation(s)
- Andrea Baucon
- DISTAV, University of Genoa, Genova, Italy.,Geology Office of Idanha-a-Nova, Naturtejo UNESCO Global Geopark, Idanha-a-Nova, Portugal
| | - Carlos Neto de Carvalho
- Geology Office of Idanha-a-Nova, Naturtejo UNESCO Global Geopark, Idanha-a-Nova, Portugal.,Instituto D. Luiz, Faculdade de Ciências da Universidade de Lisboa, University of Lisbon, Lisbon, Portugal
| | | | | | - Fabrizio Felletti
- Dipartimento di Scienze della Terra 'Ardito Desio', University of Milan, Milan, Italy
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11
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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
| | - 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
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12
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Klempay B, Arandia-Gorostidi N, Dekas AE, Bartlett DH, Carr CE, Doran PT, Dutta A, Erazo N, Fisher LA, Glass JB, Pontefract A, Som SM, Wilson JM, Schmidt BE, Bowman JS. Microbial diversity and activity in Southern California salterns and bitterns: analogues for remnant ocean worlds. Environ Microbiol 2021; 23:3825-3839. [PMID: 33621409 DOI: 10.1111/1462-2920.15440] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 02/12/2021] [Accepted: 02/15/2021] [Indexed: 01/02/2023]
Abstract
Concurrent osmotic and chaotropic stress make MgCl2 -rich brines extremely inhospitable environments. Understanding the limits of life in these brines is essential to the search for extraterrestrial life on contemporary and relict ocean worlds, like Mars, which could host similar environments. We sequenced environmental 16S rRNA genes and quantified microbial activity across a broad range of salinity and chaotropicity at a Mars-analogue salt harvesting facility in Southern California, where seawater is evaporated in a series of ponds ranging from kosmotropic NaCl brines to highly chaotropic MgCl2 brines. Within NaCl brines, we observed a proliferation of specialized halophilic Euryarchaeota, which corresponded closely with the dominant taxa found in salterns around the world. These communities were characterized by very slow growth rates and high biomass accumulation. As salinity and chaotropicity increased, we found that the MgCl2 -rich brines eventually exceeded the limits of microbial activity. We found evidence that exogenous genetic material is preserved in these chaotropic brines, producing an unexpected increase in diversity in the presumably sterile MgCl2 -saturated brines. Because of their high potential for biomarker preservation, chaotropic brines could therefore serve as repositories of genetic biomarkers from nearby environments (both on Earth and beyond) making them prime targets for future life-detection missions.
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Affiliation(s)
- Benjamin Klempay
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92037, USA
| | | | - Anne E Dekas
- Department of Earth System Science, Stanford University, Stanford, CA, 94305, USA
| | - Douglas H Bartlett
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92037, USA
| | - Christopher E Carr
- Daniel Guggenheim School of Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.,School of Earth and Atmospheric Studies, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Peter T Doran
- Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Avishek Dutta
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92037, USA
| | - Natalia Erazo
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92037, USA
| | - Luke A Fisher
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92037, USA
| | - Jennifer B Glass
- School of Earth and Atmospheric Studies, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | | | - Sanjoy M Som
- Blue Marble Space Institute of Science, Seattle, WA, 98154, USA
| | - Jesse M Wilson
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92037, USA
| | - Britney E Schmidt
- School of Earth and Atmospheric Studies, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Jeff S Bowman
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92037, USA
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13
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McMahon S, Parnell J, Reekie PBR. Mars-Analog Calcium Sulfate Veins Record Evidence of Ancient Subsurface Life. ASTROBIOLOGY 2020; 20:1212-1223. [PMID: 32985907 DOI: 10.1089/ast.2019.2172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Ancient veins of calcium sulfate minerals (anhydrite, bassanite, and gypsum) deposited by subsurface aqueous fluids crosscut fluviolacustrine sedimentary rocks at multiple localities on Mars. Although these veins have been considered an attractive target for astrobiological investigation, their potential to preserve biosignatures is poorly understood. Here, we report the presence of biogenic authigenic pyrite in a fibrous gypsum vein of probable Cenozoic emplacement age from Permian lacustrine rocks in Northwest England. Pyrite occurs at the vein margins and displays a complex interfingering boundary with the surrounding gypsum suggestive of replacive authigenic growth. Gypsum-entombed carbonaceous material of probable organic origin was also identified by Raman spectroscopic microscopy in close proximity to the pyrite. Spatially resolved ion microprobe (SIMS) measurements reveal that the pyrite sulfur isotope composition is consistently very light (δ34SVCDT = -30.7‰). Comparison with the sulfate in the vein gypsum (δ34SVCDT = +8.5‰) indicates a fractionation too large to be explained by nonbiological (thermochemical) sulfate reduction. We infer that the pyrite was precipitated by microorganisms coupling the reduction of vein-derived sulfate with the oxidation of wall-derived organic matter. This is the first evidence that such veins can incorporate biosignatures that remain stable over geological time, which could be detected in samples returned from Mars.
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Affiliation(s)
- S McMahon
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
- School of Geosciences, Grant Institute, University of Edinburgh, Edinburgh, UK
| | - J Parnell
- School of Geosciences, University of Aberdeen, King's College, Aberdeen, UK
| | - P B R Reekie
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
- School of Geosciences, Grant Institute, University of Edinburgh, Edinburgh, UK
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14
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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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15
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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: 6] [Impact Index Per Article: 1.5] [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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16
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Olsson-Francis K, Ramkissoon NK, Macey MC, Pearson VK, Schwenzer SP, Johnson DN. Simulating microbial processes in extraterrestrial, aqueous environments. J Microbiol Methods 2020; 172:105883. [PMID: 32119957 DOI: 10.1016/j.mimet.2020.105883] [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: 09/27/2019] [Revised: 02/28/2020] [Accepted: 02/28/2020] [Indexed: 10/24/2022]
Abstract
Finding evidence of life elsewhere in the Solar System is dependent on understanding biotic processes that could occur within potentially habitable environments. Here, we describe a suite of high-pressure flow-through reactors that have been developed to investigate biotic and abiotic processes within simulated sub-surface martian and icy moon environments.
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Affiliation(s)
- K Olsson-Francis
- STEM Faculty, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK.
| | - N K Ramkissoon
- STEM Faculty, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
| | - M C Macey
- STEM Faculty, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
| | - V K Pearson
- STEM Faculty, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
| | - S P Schwenzer
- STEM Faculty, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
| | - D N Johnson
- STEM Faculty, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
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17
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Wilks JM, Chen F, Clark BC, Schneegurt MA. Bacterial Growth in Saturated and Eutectic Solutions of Magnesium Sulphate and Potassium Chlorate with Relevance to Mars and the Ocean Worlds. INTERNATIONAL JOURNAL OF ASTROBIOLOGY 2019; 18:502-509. [PMID: 33776587 PMCID: PMC7992186 DOI: 10.1017/s1473550418000502] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Liquid water on Mars might be created by deliquescence of hygroscopic salts or by permafrost melts, both potentially forming saturated brines. Freezing point depression allows these heavy brines to remain liquid in the near-surface environment for extended periods, perhaps as eutectic solutions, at the lowest temperatures and highest salt concentrations where ices and precipitates do not form. Perchlorate and chlorate salts and iron sulfate form brines with low eutectic temperatures and may persist under Mars near-surface conditions, but are chemically harsh at high concentrations and were expected to be incompatible with life, while brines of common sulfate salts on Mars may be more suitable for microbial growth. Microbial growth in saturated brines also may be relevant beyond Mars, to the oceans of Ceres, Enceladus, Europa and Pluto. We have previously shown strong growth of salinotolerant bacteria in media containing 2 M MgSO4 heptahydrate (~50% w/v) at 25 °C. Here we extend those observations to bacterial isolates from Basque Lake, BC and Hot Lake, WA, that grow well in saturated MgSO4 medium (67%) at 25 °C and in 50% MgSO4 medium at 4 °C (56% would be saturated). Psychrotolerant, salinotolerant microbes isolated from Basque Lake soils included Halomonas and Marinococcus, which were identified by 16S rRNA gene sequencing and characterized phenetically. Eutectic liquid medium constituted by 43% MgSO4 at -4 °C supported copious growth of these psychrotolerant Halomonas isolates, among others. Bacterial isolates also grew well at the eutectic for K chlorate (3% at -3 °C). Survival and growth in eutectic solutions increases the possibility that microbes contaminating spacecraft pose a contamination risk to Mars. The cold brines of sulfate and (per)chlorate salts that may form at times on Mars through deliquescence or permafrost melt have now been demonstrated to be suitable microbial habitats, should appropriate nutrients be available and dormant cells become vegetative.
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Affiliation(s)
- Jonathan M. Wilks
- Department of Biological Sciences, Wichita State University, Wichita, KS
| | - Fei Chen
- Planetary Protection Group, Jet Propulsion Laboratory, Pasadena CA
| | | | - Mark A. Schneegurt
- Department of Biological Sciences, Wichita State University, Wichita, KS
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18
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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: 37] [Impact Index Per Article: 7.4] [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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19
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Onstott T, Ehlmann B, Sapers H, Coleman M, Ivarsson M, Marlow J, Neubeck A, Niles P. Paleo-Rock-Hosted Life on Earth and the Search on Mars: A Review and Strategy for Exploration. ASTROBIOLOGY 2019; 19:1230-1262. [PMID: 31237436 PMCID: PMC6786346 DOI: 10.1089/ast.2018.1960] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 04/25/2019] [Indexed: 05/19/2023]
Abstract
Here we review published studies on the abundance and diversity of terrestrial rock-hosted life, the environments it inhabits, the evolution of its metabolisms, and its fossil biomarkers to provide guidance in the search for life on Mars. Key findings are (1) much terrestrial deep subsurface metabolic activity relies on abiotic energy-yielding fluxes and in situ abiotic and biotic recycling of metabolic waste products rather than on buried organic products of photosynthesis; (2) subsurface microbial cell concentrations are highest at interfaces with pronounced chemical redox gradients or permeability variations and do not correlate with bulk host rock organic carbon; (3) metabolic pathways for chemolithoautotrophic microorganisms evolved earlier in Earth's history than those of surface-dwelling phototrophic microorganisms; (4) the emergence of the former occurred at a time when Mars was habitable, whereas the emergence of the latter occurred at a time when the martian surface was not continually habitable; (5) the terrestrial rock record has biomarkers of subsurface life at least back hundreds of millions of years and likely to 3.45 Ga with several examples of excellent preservation in rock types that are quite different from those preserving the photosphere-supported biosphere. These findings suggest that rock-hosted life would have been more likely to emerge and be preserved in a martian context. Consequently, we outline a Mars exploration strategy that targets subsurface life and scales spatially, focusing initially on identifying rocks with evidence for groundwater flow and low-temperature mineralization, then identifying redox and permeability interfaces preserved within rock outcrops, and finally focusing on finding minerals associated with redox reactions and associated traces of carbon and diagnostic chemical and isotopic biosignatures. Using this strategy on Earth yields ancient rock-hosted life, preserved in the fossil record and confirmable via a suite of morphologic, organic, mineralogical, and isotopic fingerprints at micrometer scale. We expect an emphasis on rock-hosted life and this scale-dependent strategy to be crucial in the search for life on Mars.
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Affiliation(s)
- T.C. Onstott
- Department of Geosciences, Princeton University, Princeton, New Jersey, USA
- Address correspondence to: T.C. Onstott, Department of Geosciences, Princeton University,, Princeton, NJ 008544
| | - B.L. Ehlmann
- Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, California, USA
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
- B.L. Ehlmann, Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, CA 91125
| | - H. Sapers
- Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, California, USA
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
| | - M. Coleman
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
- NASA Astrobiology Institute, Pasadena, California, USA
| | - M. Ivarsson
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - J.J. Marlow
- Department of Organismic & Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA
| | - A. Neubeck
- Department of Earth Sciences, Uppsala University, Uppsala, Sweden
| | - P. Niles
- Astromaterials Research and Exploration Science Division, NASA Johnson Space Center, Houston, Texas, USA
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20
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Microbial Markers Profile in Anaerobic Mars Analogue Environments Using the LDChip (Life Detector Chip) Antibody Microarray Core of the SOLID (Signs of Life Detector) Platform. Microorganisms 2019; 7:microorganisms7090365. [PMID: 31540500 PMCID: PMC6780502 DOI: 10.3390/microorganisms7090365] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/30/2019] [Accepted: 09/16/2019] [Indexed: 11/30/2022] Open
Abstract
One of the main objectives for astrobiology is to unravel and explore the habitability of environments beyond Earth, paying special attention to Mars. If the combined environmental stress factors on Mars are compatible with life or if they were less harsh in the past, to investigate the traces of past or present life is critical to understand its potential habitability. Essential for this research is the characterization of Mars analogue environments on Earth through the development of techniques for biomarker detection in them. Biosensing techniques based on fluorescence sandwich microarray immunoassays (FSMI) have shown to be a powerful tool to detect biosignatures and depict the microbial profiles of different environments. In this study, we described the microbial biomarker profile of five anoxic Mars analogues sites using the Life Detector Chip (LDChip), an antibody microarray for multiple microbial marker detection. Furthermore, we contributed to new targets by developing a new 26-polyclonal antibodies microarray using crude extracts from anaerobic sampling sites, halophilic microorganisms, and anaerobic isolates obtained in the framework of the European Mars Analogues for Space Exploration (MASE) project. The new subset of antibodies was characterized and implemented into a microarray platform (MASE-Chip) for microbial marker searching in salty and anaerobic environments.
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21
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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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22
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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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23
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Becerra-Herrera M, Moraga SD, Cruz-Hernández P, Molinas R, Richter P, Caraballo MA. Detection and assignment of inorganic aqueous polymers relevant to environmental nanogeoscience by direct infusion electrospray ionization mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2019; 54:495-506. [PMID: 30907977 DOI: 10.1002/jms.4356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 03/12/2019] [Accepted: 03/18/2019] [Indexed: 06/09/2023]
Abstract
Inorganic polymers in aqueous solutions are being proposed as essential components in new theories concerning nonclassical nucleation and growth of nanominerals relevant to environmental nanogeosciences. The study of those complex natural processes requires multi-technique analytical approaches able to characterize the solutions and their constituents (solutes, oligomers, polymers, clusters and nanominerals) from atomic to micrometric scales. A novel analytical approach involving an electrospray ionization source (ESI) coupled to time-of-flight mass spectrometry (TOF/MS) was developed to identify inorganic polymers in aqueous solution. To this end, the presence of initial Al oligomers and their polymerization processes was studied during a nanomineral aqueous synthesis (hydrobasaluminte, Al4 SO4 (OH)10 ·12-36H2 O). Ensuring the feasibility and robustness of the methodology as well as the stability of the polymers under study (avoiding undesirable fragmentation), a meticulous study of the ESI-TOF MS working conditions was performed. Precision of the methodology was evaluated obtaining relative standard deviations below 3.3%. For the first time in the study of inorganic polymers in the earth sciences, the mass accuracy error (ppm) has been reported and the use of significant decimal figures of the m/z signal has been taken into account. Complementary to this, a four-step polymer assignment methodology and a database with the Al- and Al-SO4 2- polymers assigned were created. Several polymers have been assigned for the first time, including Al (SO4 )+ ·H2 O, Al2 O(SO4 )2+ ·H2 O, Al5 O4 (OH)5 2+ ·2H2 O, and Al3 O5 (OH)2- ·4H2 O, among others. The results obtained in the present study help create a foundation to include mass spectrometry as a routine analytical technique to study mineral formation in aqueous solution.
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Affiliation(s)
| | | | | | | | - Pablo Richter
- Department of Inorganic and Analytical Chemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Santiago, Chile
| | - Manuel A Caraballo
- Department of Mining Engineering, University of Chile, Santiago, Chile
- AMTC, University of Chile, Santiago, Chile
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24
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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: 19] [Impact Index Per Article: 3.8] [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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25
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La Cono V, Bortoluzzi G, Messina E, La Spada G, Smedile F, Giuliano L, Borghini M, Stumpp C, Schmitt-Kopplin P, Harir M, O'Neill WK, Hallsworth JE, Yakimov M. The discovery of Lake Hephaestus, the youngest athalassohaline deep-sea formation on Earth. Sci Rep 2019; 9:1679. [PMID: 30737448 PMCID: PMC6368551 DOI: 10.1038/s41598-018-38444-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 12/27/2018] [Indexed: 12/30/2022] Open
Abstract
Hydrated, magnesium-rich minerals and subglacial brines exist on the martian surface, so the habitability of high-Mg2+ environments on Earth has extraterrestrial (as well as terrestrial) implications. Here, we report the discovery of a MgCl2-dominated (4.72 M) brine lake on the floor of the Mediterranean Ridge that underlies a 3500-m water column, and name it Lake Hephaestus. Stable isotope analyses indicated that the Hephaestus brine is derived from interactions between ancient bishofite-enriched evaporites and subsurface fluids. Analyses of sediment pore waters indicated that the Hephaestus depression had contained the MgCl2 brine for a remarkably short period; only 700 years. Lake Hephaestus is, therefore, the youngest among currently known submarine athalassohaline brine lakes on Earth. Due to its biologically hostile properties (low water-activity and extreme chaotropicity), the Hephaestus brine is devoid of life. By contrast, the seawater-Hephaestus brine interface has been shown to act as refuge for extremely halophilic and magnesium-adapted stratified communities of microbes, even at MgCl2 concentrations that approach the water-activity limit for life (0.653).
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Affiliation(s)
- Violetta La Cono
- CNR, Institute for Coastal Marine Environment, Messina, 98122, Italy
| | | | - Enzo Messina
- CNR, Institute for Coastal Marine Environment, Messina, 98122, Italy
| | - Gina La Spada
- CNR, Institute for Coastal Marine Environment, Messina, 98122, Italy
| | - Francesco Smedile
- CNR, Institute for Coastal Marine Environment, Messina, 98122, Italy
| | - Laura Giuliano
- Mediterranean Science Commission (CIESM), MC, 98000, Monaco
| | | | - Christine Stumpp
- Institute of Groundwater Ecology, Helmholtz Centre Munich, Neuherberg, 85764, Germany.,Institute of Hydraulics and Rural Water Management, University of Natural Resources and Life Sciences Vienna, Wien, 1190, Austria
| | - Philippe Schmitt-Kopplin
- Research Unit Analytical BioGeoChemistry, Helmholtz Centre Munich, Neuherberg, 85764, Germany.,Technische Universität München, Lehrstuhl für Analytische Lebensmittelchemie, Freising, 85354, Germany
| | - Mourad Harir
- Research Unit Analytical BioGeoChemistry, Helmholtz Centre Munich, Neuherberg, 85764, Germany
| | - William K O'Neill
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK
| | - John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK
| | - Michail Yakimov
- CNR, Institute for Coastal Marine Environment, Messina, 98122, Italy. .,Institute of Living Systems, Immanuel Kant Baltic Federal University, Kaliningrad, 236016, Russia.
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26
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Khaleque HN, González C, Shafique R, Kaksonen AH, Holmes DS, Watkin ELJ. Uncovering the Mechanisms of Halotolerance in the Extremely Acidophilic Members of the Acidihalobacter Genus Through Comparative Genome Analysis. Front Microbiol 2019; 10:155. [PMID: 30853944 PMCID: PMC6396713 DOI: 10.3389/fmicb.2019.00155] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/22/2019] [Indexed: 12/21/2022] Open
Abstract
There are few naturally occurring environments where both acid and salinity stress exist together, consequently, there has been little evolutionary pressure for microorganisms to develop systems that enable them to deal with both stresses simultaneously. Members of the genus Acidihalobacter are iron- and sulfur-oxidizing, halotolerant acidophiles that have developed the ability to tolerate acid and saline stress and, therefore, have the potential to bioleach ores with brackish or saline process waters under acidic conditions. The genus consists of four members, A. prosperus DSM 5130T, A. prosperus DSM 14174, A. prosperus F5 and "A. ferrooxidans" DSM 14175. An in depth genome comparison was undertaken in order to provide a more comprehensive description of the mechanisms of halotolerance used by the different members of this genus. Pangenome analysis identified 29, 3 and 9 protein families related to halotolerance in the core, dispensable and unique genomes, respectively. The genes for halotolerance showed Ka/Ks ratios between 0 and 0.2, confirming that they are conserved and stabilized. All the Acidihalobacter genomes contained similar genes for the synthesis and transport of ectoine, which was recently found to be the dominant osmoprotectant in A. prosperus DSM 14174 and A. prosperus DSM 5130T. Similarities also existed in genes encoding low affinity potassium pumps, however, A. prosperus DSM 14174 was also found to contain genes encoding high affinity potassium pumps. Furthermore, only A. prosperus DSM 5130T and "A. ferrooxidans" DSM 14175 contained genes allowing the uptake of taurine as an osmoprotectant. Variations were also seen in genes encoding proteins involved in the synthesis and/or transport of periplasmic glucans, sucrose, proline, and glycine betaine. This suggests that versatility exists in the Acidihalobacter genus in terms of the mechanisms they can use for halotolerance. This information is useful for developing hypotheses for the search for life on exoplanets and moons.
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Affiliation(s)
- Himel N. Khaleque
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, WA, Australia
- CSIRO Land and Water, Floreat, WA, Australia
| | - Carolina González
- Center for Bioinformatics and Genome Biology, Science for Life Foundation, Santiago, Chile
| | | | | | - David S. Holmes
- Center for Bioinformatics and Genome Biology, Science for Life Foundation, Santiago, Chile
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
| | - Elizabeth L. J. Watkin
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, WA, Australia
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27
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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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28
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McMahon S, Bosak T, Grotzinger JP, Milliken RE, Summons RE, Daye M, Newman SA, Fraeman A, Williford KH, Briggs DEG. A Field Guide to Finding Fossils on Mars. JOURNAL OF GEOPHYSICAL RESEARCH. PLANETS 2018; 123:1012-1040. [PMID: 30034979 PMCID: PMC6049883 DOI: 10.1029/2017je005478] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 03/28/2018] [Accepted: 04/23/2018] [Indexed: 05/05/2023]
Abstract
The Martian surface is cold, dry, exposed to biologically harmful radiation and apparently barren today. Nevertheless, there is clear geological evidence for warmer, wetter intervals in the past that could have supported life at or near the surface. This evidence has motivated National Aeronautics and Space Administration and European Space Agency to prioritize the search for any remains or traces of organisms from early Mars in forthcoming missions. Informed by (1) stratigraphic, mineralogical and geochemical data collected by previous and current missions, (2) Earth's fossil record, and (3) experimental studies of organic decay and preservation, we here consider whether, how, and where fossils and isotopic biosignatures could have been preserved in the depositional environments and mineralizing media thought to have been present in habitable settings on early Mars. We conclude that Noachian-Hesperian Fe-bearing clay-rich fluvio-lacustrine siliciclastic deposits, especially where enriched in silica, currently represent the most promising and best understood astropaleontological targets. Siliceous sinters would also be an excellent target, but their presence on Mars awaits confirmation. More work is needed to improve our understanding of fossil preservation in the context of other environments specific to Mars, particularly within evaporative salts and pore/fracture-filling subsurface minerals.
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Affiliation(s)
- S. McMahon
- Department of Geology and GeophysicsYale UniversityNew HavenCTUSA
- UK Centre for Astrobiology, School of Physics and AstronomyUniversity of EdinburghEdinburghUK
| | - T. Bosak
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMAUSA
| | - J. P. Grotzinger
- Division of Geological and Planetary SciencesCalifornia Institute of TechnologyPasadenaCAUSA
| | - R. E. Milliken
- Department of Earth, Environmental and Planetary SciencesBrown UniversityProvidenceRIUSA
| | - R. E. Summons
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMAUSA
| | - M. Daye
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMAUSA
| | - S. A. Newman
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMAUSA
| | - A. Fraeman
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - K. H. Williford
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - D. E. G. Briggs
- Department of Geology and GeophysicsYale UniversityNew HavenCTUSA
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29
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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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30
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31
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Sapers HM, Ronholm J, Raymond-Bouchard I, Comrey R, Osinski GR, Whyte LG. Biological Characterization of Microenvironments in a Hypersaline Cold Spring Mars Analog. Front Microbiol 2017; 8:2527. [PMID: 29312221 PMCID: PMC5744183 DOI: 10.3389/fmicb.2017.02527] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 12/05/2017] [Indexed: 11/13/2022] Open
Abstract
While many habitable niches on Earth are characterized by permanently cold conditions, little is known about the spatial structure of seasonal communities and the importance of substrate-cell associations in terrestrial cyroenvironments. Here we use the 16S rRNA gene as a marker for genetic diversity to compare two visually distinct but spatially integrated surface microbial mats on Axel Heiberg Island, Canadian high arctic, proximal to a perennial saline spring. This is the first study to describe the bacterial diversity in microbial mats on Axel Heiberg Island. The hypersaline springs on Axel Heiberg represent a unique analog to putative subsurface aquifers on Mars. The Martian subsurface represents the longest-lived potentially habitable environment on Mars and a better understanding of the microbial communities on Earth that thrive in analog conditions will help direct future life detection missions. The microbial mats sampled on Axel Heiberg are only visible during the summer months in seasonal flood plains formed by melt water and run-off from the proximal spring. Targeted-amplicon sequencing revealed that not only does the bacterial composition of the two mat communities differ substantially from the sediment community of the proximal cold spring, but that the mat communities are distinct from any other microbial community in proximity to the Arctic springs studied to date. All samples are dominated by Gammaproteobacteria: Thiotichales is dominant within the spring samples while Alteromonadales comprises a significant component of the mat communities. The two mat samples differ in their Thiotichales:Alteromonadales ratio and contribution of Bacteroidetes to overall diversity. The red mats have a greater proportion of Alteromonadales and Bacteroidetes reads. The distinct bacterial composition of the mat bacterial communities suggests that the spring communities are not sourced from the surface, and that seasonal melt events create ephemerally habitable niches with distinct microbial communities in the Canadian high arctic. The finding that these surficial complex microbial communities exist in close proximity to perennial springs demonstrates the existence of a transiently habitable niche in an important Mars analog site.
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Affiliation(s)
- Haley M. Sapers
- Centre for Planetary Science and Exploration, Faculty of Science, Western Science Centre, Western University, London, ON, Canada
- Department of Earth Sciences, University of Western Ontario, London, ON, Canada
- Department of Natural Resource Sciences, McGill University, Montreal, QC, Canada
| | - Jennifer Ronholm
- Department of Food Science and Agricultural Chemistry, McGill University, Montreal, QC, Canada
- Department of Animal Science, Faculty of Agricultural and Environmental Sciences, McGill University, Montreal, QC, Canada
| | | | - Raven Comrey
- Department of Natural Resource Sciences, McGill University, Montreal, QC, Canada
| | - Gordon R. Osinski
- Centre for Planetary Science and Exploration, Faculty of Science, Western Science Centre, Western University, London, ON, Canada
- Department of Earth Sciences, University of Western Ontario, London, ON, Canada
- Department of Physics and Astronomy, University of Western Ontario, London, ON, Canada
| | - Lyle G. Whyte
- Department of Natural Resource Sciences, McGill University, Montreal, QC, Canada
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32
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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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33
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Ruecker A, Schröder C, Byrne J, Weigold P, Behrens S, Kappler A. Geochemistry and Mineralogy of Western Australian Salt Lake Sediments: Implications for Meridiani Planum on Mars. ASTROBIOLOGY 2016; 16:525-538. [PMID: 27258848 DOI: 10.1089/ast.2015.1429] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
UNLABELLED Hypersaline lakes are characteristic for Western Australia and display a rare combination of geochemical and mineralogical properties that make these lakes potential analogues for past conditions on Mars. In our study, we focused on the geochemistry and mineralogy of Lake Orr and Lake Whurr. While both lakes are poor in organic carbon (<1%), the sediments' pH values differ and range from 3.8 to 4.8 in Lake Orr and from 5.4 to 6.3 in Lake Whurr sediments. Lake Whurr sediments were dominated by orange and red sediment zones in which the main Fe minerals were identified as hematite, goethite, and tentatively jarosite and pyrite. Lake Orr was dominated by brownish and blackish sediments where the main Fe minerals were goethite and another paramagnetic Fe(III)-phase that could not be identified. Furthermore, a likely secondary Fe(II)-phase was observed in Lake Orr sediments. The mineralogy of these two salt lakes in the sampling area is strongly influenced by events such as flooding, evaporation, and desiccation, processes that explain at least to some extent the observed differences between Lake Orr and Lake Whurr. The iron mineralogy of Lake Whurr sediments and the high salinity make this lake a suitable analogue for Meridiani Planum on Mars, and in particular the tentative identification of pyrite in Lake Whurr sediments has implications for the interpretation of the Fe mineralogy of Meridiani Planum sediments. KEY WORDS Western Australia-Salt lakes-Jarosite-Hematite-Pyrite-Mars analogue. Astrobiology 16, 525-538.
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Affiliation(s)
- A Ruecker
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
| | - C Schröder
- 2 Biological and Environmental Sciences, School of Natural Sciences, University of Stirling , Stirling, Scotland, UK
| | - J Byrne
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
| | - P Weigold
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
| | - S Behrens
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
| | - A Kappler
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
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34
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Wang J, Lowenstein TK, Fang X. Microbial Habitability and Pleistocene Aridification of the Asian Interior. ASTROBIOLOGY 2016; 16:379-388. [PMID: 27159080 DOI: 10.1089/ast.2015.1397] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
UNLABELLED Fluid inclusions trapped in ancient halite can contain a community of halophilic prokaryotes and eukaryotes that inhabited the surface brines from which the halite formed. Long-term survival of bacteria and archaea and preservation of DNA have been reported from halite, but little is known about the distribution of microbes in buried evaporites. Here we report the discovery of prokaryotes and single-celled algae in fluid inclusions in Pleistocene halite, up to 2.26 Ma in age, from the Qaidam Basin, China. We show that water activity (aw), a measure of water availability and an environmental control on biological habitability in surface brines, is also related to microbe entrapment in fluid inclusions. The aw of Qaidam Basin brines progressively decreased over the last ∼1 million years, driven by aridification of the Asian interior, which led to decreased precipitation and water inflow and heightened evaporation rates. These changes in water balance produced highly concentrated brines, which reduced the habitability of surface lakes and decreased the number of microbes trapped in halite. By 0.13 Ma, the aw of surface brines approached the limits tolerated by halophilic prokaryotes and algae. These results show the response of microbial ecosystems to climate change in an extreme environment, which will guide future studies exploring deep life on Earth and elsewhere in the Solar System. KEY WORDS Halite fluid inclusions-Ancient microbes-Water activity-Qaidam Basin-Pleistocene aridification. Astrobiology 16, 379-388.
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Affiliation(s)
- Jiuyi Wang
- 1 CAS Center for Excellence in Tibetan Plateau Earth Sciences and Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research , Chinese Academy of Sciences, Beijing, China
- 2 Department of Geological Sciences and Environmental Studies, State University of New York , Binghamton, New York, USA
| | - Tim K Lowenstein
- 2 Department of Geological Sciences and Environmental Studies, State University of New York , Binghamton, New York, USA
| | - Xiaomin Fang
- 1 CAS Center for Excellence in Tibetan Plateau Earth Sciences and Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research , Chinese Academy of Sciences, Beijing, China
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Fox-Powell MG, Hallsworth JE, Cousins CR, Cockell CS. Ionic Strength Is a Barrier to the Habitability of Mars. ASTROBIOLOGY 2016; 16:427-42. [PMID: 27213516 DOI: 10.1089/ast.2015.1432] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
UNLABELLED The thermodynamic availability of water (water activity) strictly limits microbial propagation on Earth, particularly in hypersaline environments. A considerable body of evidence indicates the existence of hypersaline surface waters throughout the history of Mars; therefore it is assumed that, as on Earth, water activity is a major limiting factor for martian habitability. However, the differing geological histories of Earth and Mars have driven variations in their respective aqueous geochemistry, with as-yet-unknown implications for habitability. Using a microbial community enrichment approach, we investigated microbial habitability for a suite of simulated martian brines. While the habitability of some martian brines was consistent with predictions made from water activity, others were uninhabitable even when the water activity was biologically permissive. We demonstrate experimentally that high ionic strength, driven to extremes on Mars by the ubiquitous occurrence of multivalent ions, renders these environments uninhabitable despite the presence of biologically available water. These findings show how the respective geological histories of Earth and Mars, which have produced differences in the planets' dominant water chemistries, have resulted in different physicochemical extremes which define the boundary space for microbial habitability. KEY WORDS Habitability-Mars-Salts-Water activity-Life in extreme environments. Astrobiology 16, 427-442.
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Affiliation(s)
- Mark G Fox-Powell
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , UK
| | - John E Hallsworth
- 2 Institute for Global Food Security, Queen's University Belfast , UK
| | - Claire R Cousins
- 3 Department of Earth and Environmental Sciences, University of St. Andrews , UK
| | - Charles S Cockell
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , UK
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Stawski TM, van Driessche AES, Ossorio M, Diego Rodriguez-Blanco J, Besselink R, Benning LG. Formation of calcium sulfate through the aggregation of sub-3 nanometre primary species. Nat Commun 2016; 7:11177. [PMID: 27034256 PMCID: PMC4821993 DOI: 10.1038/ncomms11177] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 02/26/2016] [Indexed: 12/22/2022] Open
Abstract
The formation pathways of gypsum remain uncertain. Here, using truly in situ and fast time-resolved small-angle X-ray scattering, we quantify the four-stage solution-based nucleation and growth of gypsum (CaSO4·2H2O), an important mineral phase on Earth and Mars. The reaction starts through the fast formation of well-defined, primary species of <3 nm in length (stage I), followed in stage II by their arrangement into domains. The variations in volume fractions and electron densities suggest that these fast forming primary species contain Ca–SO4-cores that self-assemble in stage III into large aggregates. Within the aggregates these well-defined primary species start to grow (stage IV), and fully crystalize into gypsum through a structural rearrangement. Our results allow for a quantitative understanding of how natural calcium sulfate deposits may form on Earth and how a terrestrially unstable phase-like bassanite can persist at low-water activities currently dominating the surface of Mars. The quantitative understanding of how gypsum nucleates and grows from aqueous solutions is limited. Here, the authors demonstrate how, by using truly in situ and fast time-resolved small-angle X-ray scattering, the four-stage solution-based nucleation and growth of this mineral can be quantified.
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Affiliation(s)
- Tomasz M Stawski
- School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK.,German Research Centre for Geosciences, GFZ, 14473 Potsdam, Germany
| | - Alexander E S van Driessche
- LEC, IACT, CSIC-UGR, E-18100 Armilla, Spain.,Structural Biology Brussels, VUB, 1050 Brussels, Belgium.,CNRS, ISTerre, F-38041 Grenoble, France
| | | | | | - Rogier Besselink
- German Research Centre for Geosciences, GFZ, 14473 Potsdam, Germany
| | - Liane G Benning
- School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK.,German Research Centre for Geosciences, GFZ, 14473 Potsdam, Germany
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Martin D, Cockell CS. PELS (Planetary Environmental Liquid Simulator): a new type of simulation facility to study extraterrestrial aqueous environments. ASTROBIOLOGY 2015; 15:111-118. [PMID: 25651097 DOI: 10.1089/ast.2014.1240] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Investigations of other planetary bodies, including Mars and icy moons such as Enceladus and Europa, show that they may have hosted aqueous environments in the past and may do so even today. Therefore, a major challenge in astrobiology is to build facilities that will allow us to study the geochemistry and habitability of these extraterrestrial environments. Here, we describe a simulation facility (PELS: Planetary Environmental Liquid Simulator) with the capability for liquid input and output that allows for the study of such environments. The facility, containing six separate sample vessels, allows for statistical replication of samples. Control of pressure, gas composition, UV irradiation conditions, and temperature allows for the precise replication of aqueous conditions, including subzero brines under martian atmospheric conditions. A sample acquisition system allows for the collection of both liquid and solid samples from within the chamber without breaking the atmospheric conditions, enabling detailed studies of the geochemical evolution and habitability of past and present extraterrestrial environments. The facility we describe represents a new frontier in planetary simulation-continuous flow-through simulation of extraterrestrial aqueous environments.
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Affiliation(s)
- Derek Martin
- School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
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Hutchinson IB, Ingley R, Edwards HGM, Harris L, McHugh M, Malherbe C, Parnell J. Raman spectroscopy on Mars: identification of geological and bio-geological signatures in Martian analogues using miniaturized Raman spectrometers. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2014; 372:rsta.2014.0204. [PMID: 25368350 DOI: 10.1098/rsta.2014.0204] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The first Raman spectrometers to be used for in situ analysis of planetary material will be launched as part of powerful, rover-based analytical laboratories within the next 6 years. There are a number of significant challenges associated with building spectrometers for space applications, including limited volume, power and mass budgets, the need to operate in harsh environments and the need to operate independently and intelligently for long periods of time (due to communication limitations). Here, we give an overview of the technical capabilities of the Raman instruments planned for future planetary missions and give a review of the preparatory work being pursued to ensure that such instruments are operated successfully and optimally. This includes analysis of extremophile samples containing pigments associated with biological processes, synthetic materials which incorporate biological material within a mineral matrix, planetary analogues containing low levels of reduced carbon and samples coated with desert varnish that incorporate both geo-markers and biomarkers. We discuss the scientific importance of each sample type and the challenges using portable/flight-prototype instrumentation. We also report on technical development work undertaken to enable the next generation of Raman instruments to reach higher levels of sensitivity and operational efficiency.
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Affiliation(s)
- Ian B Hutchinson
- Department of Physics and Astronomy, Space Research Centre, University of Leicester, Leicester LE1 7RH, UK
| | - Richard Ingley
- Department of Physics and Astronomy, Space Research Centre, University of Leicester, Leicester LE1 7RH, UK
| | - Howell G M Edwards
- Department of Physics and Astronomy, Space Research Centre, University of Leicester, Leicester LE1 7RH, UK
| | - Liam Harris
- Department of Physics and Astronomy, Space Research Centre, University of Leicester, Leicester LE1 7RH, UK
| | - Melissa McHugh
- Department of Physics and Astronomy, Space Research Centre, University of Leicester, Leicester LE1 7RH, UK
| | - Cedric Malherbe
- Department of Physics and Astronomy, Space Research Centre, University of Leicester, Leicester LE1 7RH, UK Department of Inorganic Analytical Chemistry, Chemistry Institute (B6c), University of Liège, 4000 Liège, Belgium
| | - J Parnell
- Department of Geology & Petroleum Geology, University of Aberdeen, King's College, Aberdeen AB24 3UE, UK
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Stevenson A, Burkhardt J, Cockell CS, Cray JA, Dijksterhuis J, Fox-Powell M, Kee TP, Kminek G, McGenity TJ, Timmis KN, Timson DJ, Voytek MA, Westall F, Yakimov MM, Hallsworth JE. Multiplication of microbes below 0.690 water activity: implications for terrestrial and extraterrestrial life. Environ Microbiol 2014; 17:257-77. [DOI: 10.1111/1462-2920.12598] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 08/08/2014] [Accepted: 08/14/2014] [Indexed: 01/25/2023]
Affiliation(s)
- Andrew Stevenson
- Institute for Global Food Security; School of Biological Sciences; MBC; Queen's University Belfast; Belfast BT9 7BL Northern Ireland
| | - Jürgen Burkhardt
- Plant Nutrition Group; Institute of Crop Science and Resource Conservation; University of Bonn; Karlrobert-Kreiten-Str. 13 D-53115 Bonn Germany
| | - Charles S. Cockell
- UK Centre for Astrobiology; School of Physics and Astronomy; University of Edinburgh; Edinburgh EH9 3JZ UK
| | - Jonathan A. Cray
- Institute for Global Food Security; School of Biological Sciences; MBC; Queen's University Belfast; Belfast BT9 7BL Northern Ireland
| | - Jan Dijksterhuis
- CBS Fungal Biodiversity Centre; Uppsalalaan 8 CT 3584 Utrecht The Netherlands
| | - Mark Fox-Powell
- UK Centre for Astrobiology; School of Physics and Astronomy; University of Edinburgh; Edinburgh EH9 3JZ UK
| | - Terence P. Kee
- School of Chemistry; University of Leeds; Leeds LS2 9JT West Yorkshire UK
| | | | - Terry J. McGenity
- School of Biological Sciences; University of Essex; Colchester CO4 3SQ Essex UK
| | - Kenneth N. Timmis
- Institute of Microbiology; Technical University Braunschweig; Spielmannstrasse 7 D-38106 Braunschweig Germany
| | - David J. Timson
- Institute for Global Food Security; School of Biological Sciences; MBC; Queen's University Belfast; Belfast BT9 7BL Northern Ireland
| | | | - Frances Westall
- Centre de Biophysique Moléculaire; CNRS; Rue Charles Sadron; Centre de Recherches sur les Matériaux à Haute Température; 1D, avenue de la recherché scientifique 45071 Orléans Cedex 2 France
| | | | - 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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Cumbers J, Rothschild LJ. Salt tolerance and polyphyly in the cyanobacterium Chroococcidiopsis (Pleurocapsales). JOURNAL OF PHYCOLOGY 2014; 50:472-82. [PMID: 26988320 DOI: 10.1111/jpy.12169] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 12/16/2013] [Indexed: 05/19/2023]
Abstract
Chroococcidiopsis Geitler (Geitler 1933) is a genus of cyanobacteria containing desiccation and radiation resistant strains. Members of the genus live in habitats ranging from hot and cold deserts to fresh and saltwater environments. Morphology and cell division pattern have historically been used to define the genus. To better understand the evolution and ability of the Chroococcidiopsis genus to survive in diverse environments we investigated how salt tolerance varies among 15 strains previously isolated from different locations, and if salt tolerant strains are monophyletic to those isolated from freshwater and land environments. Four markers were sequenced from these 15 strains, the 16S rRNA, rbcL, desC1, and gltX genes. Phylogenetic trees were generated which identified a distinct clade of salt-tolerant strains. This study demonstrates that the genus is polyphyletic based on saltwater and freshwater phenotypes. To understand the resistance to salt in more details, the strains were grown on a range of sea salt concentrations which demonstrated that the freshwater strains were salt-intolerant whilst the saltwater strains required salt for growth. This study shows an increased resolution of the phylogeny of Chroococcidiopsis and provides further evidence that the genus is polyphyletic and should be reclassified to improve clarity in the literature.
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Affiliation(s)
- John Cumbers
- NASA Ames Space Portal/SynBioBeta, NASA Ames Research Center, Mail Stop 555-2, P.O. Box 1, Moffett Field, California, 94035, USA
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Box G-W, Providence, Rhode Island, 02912, USA
| | - Lynn J Rothschild
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Box G-W, Providence, Rhode Island, 02912, USA
- Biospheric Science Branch, NASA Ames Research Center, Mail Stop 239-20, P.O. Box 1, Moffett Field, California, 94035, USA
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Cockell CS. Trajectories of martian habitability. ASTROBIOLOGY 2014; 14:182-203. [PMID: 24506485 PMCID: PMC3929387 DOI: 10.1089/ast.2013.1106] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 12/29/2013] [Indexed: 05/21/2023]
Abstract
Beginning from two plausible starting points-an uninhabited or inhabited Mars-this paper discusses the possible trajectories of martian habitability over time. On an uninhabited Mars, the trajectories follow paths determined by the abundance of uninhabitable environments and uninhabited habitats. On an inhabited Mars, the addition of a third environment type, inhabited habitats, results in other trajectories, including ones where the planet remains inhabited today or others where planetary-scale life extinction occurs. By identifying different trajectories of habitability, corresponding hypotheses can be described that allow for the various trajectories to be disentangled and ultimately a determination of which trajectory Mars has taken and the changing relative abundance of its constituent environments.
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Affiliation(s)
- Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
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Kilmer BR, Eberl TC, Cunderla B, Chen F, Clark BC, Schneegurt MA. Molecular and Phenetic Characterization of the Bacterial Assemblage of Hot Lake, WA, an Environment with High Concentrations of Magnesium Sulfate, and Its Relevance to Mars. INTERNATIONAL JOURNAL OF ASTROBIOLOGY 2014; 13:69-80. [PMID: 24748851 PMCID: PMC3989109 DOI: 10.1017/s1473550413000268] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Hot Lake (Oroville, WA) is an athalassohaline epsomite lake that can have precipitating concentrations of MgSO4 salts, mainly epsomite. Little biotic study has been done on epsomite lakes and it was unclear whether microbes isolated from epsomite lakes and their margins would fall within recognized halotolerant genera, common soil genera, or novel phyla. Our initial study cultivated and characterized epsotolerant bacteria from the lake and its margins. Approximately 100 aerobic heterotrophic microbial isolates were obtained by repetitive streak-plating in high-salt media including either 10% NaCl or 2 M MgSO4. The collected isolates were all bacteria, nearly evenly divided between Gram-positive and Gram-negative clades, the most abundant genera being Halomonas, Idiomarina, Marinobacter, Marinococcus, Nesterenkonia, Nocardiopsis, and Planococcus. Bacillus, Corynebacterium, Exiguobacterium, Kocuria, and Staphylococcus also were cultured. This initial study included culture-independent community analysis of direct DNA extracts of lake margin soil using PCR-based clone libraries and 16S rRNA gene phylogeny. Clones assigned Gram-positive bacterial clades (70% of total clones) were dominated by sequences related to uncultured actinobacteria. There were abundant Deltaproteobacteria clones related to bacterial sulfur metabolisms and clones of Legionella and Coxiella. These epsomite lake microbial communities seem to be divided between bacteria primarily associated with hyperhaline environments rich in NaCl and salinotolerant relatives of common soil organisms. Archaea appear to be in low abundance and none were isolated, despite near-saturated salinities. Growth of microbes at very high concentrations of magnesium and other sulfates has relevance to planetary protection and life-detection missions to Mars, where scant liquid water may form as deliquescent brines and appear as eutectic liquids.
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Affiliation(s)
- Brian R. Kilmer
- Department of Biological Sciences, Wichita State University, Wichita, KS
| | - Timothy C. Eberl
- Department of Biological Sciences, Wichita State University, Wichita, KS
| | | | - Fei Chen
- Planetary Protection Group, Jet Propulsion Laboratory, NASA, Pasadena, CA
| | | | - Mark A. Schneegurt
- Department of Biological Sciences, Wichita State University, Wichita, KS
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Grotzinger JP, Sumner DY, Kah LC, Stack K, Gupta S, Edgar L, Rubin D, Lewis K, Schieber J, Mangold N, Milliken R, Conrad PG, DesMarais D, Farmer J, Siebach K, Calef F, Hurowitz J, McLennan SM, Ming D, Vaniman D, Crisp J, Vasavada A, Edgett KS, Malin M, Blake D, Gellert R, Mahaffy P, Wiens RC, Maurice S, Grant JA, Wilson S, Anderson RC, Beegle L, Arvidson R, Hallet B, Sletten RS, Rice M, Bell J, Griffes J, Ehlmann B, Anderson RB, Bristow TF, Dietrich WE, Dromart G, Eigenbrode J, Fraeman A, Hardgrove C, Herkenhoff K, Jandura L, Kocurek G, Lee S, Leshin LA, Leveille R, Limonadi D, Maki J, McCloskey S, Meyer M, Minitti M, Newsom H, Oehler D, Okon A, Palucis M, Parker T, Rowland S, Schmidt M, Squyres S, Steele A, Stolper E, Summons R, Treiman A, Williams R, Yingst A, Team MS, Kemppinen O, Bridges N, Johnson JR, Cremers D, Godber A, Wadhwa M, Wellington D, McEwan I, Newman C, Richardson M, Charpentier A, Peret L, King P, Blank J, Weigle G, Li S, Robertson K, Sun V, Baker M, Edwards C, Farley K, Miller H, Newcombe M, Pilorget C, Brunet C, Hipkin V, Leveille R, Marchand G, Sanchez PS, Favot L, Cody G, Fluckiger L, Lees D, Nefian A, Martin M, Gailhanou M, Westall F, Israel G, Agard C, Baroukh J, Donny C, Gaboriaud A, Guillemot P, Lafaille V, Lorigny E, Paillet A, Perez R, Saccoccio M, Yana C, Armiens-Aparicio C, Rodriguez JC, Blazquez IC, Gomez FG, Gomez-Elvira J, Hettrich S, Malvitte AL, Jimenez MM, Martinez-Frias J, Martin-Soler J, Martin-Torres FJ, Jurado AM, Mora-Sotomayor L, Caro GM, Lopez SN, Peinado-Gonzalez V, Pla-Garcia J, Manfredi JAR, Romeral-Planello JJ, Fuentes SAS, Martinez ES, Redondo JT, Urqui-O'Callaghan R, Mier MPZ, Chipera S, Lacour JL, Mauchien P, Sirven JB, Manning H, Fairen A, Hayes A, Joseph J, Sullivan R, Thomas P, Dupont A, Lundberg A, Melikechi N, Mezzacappa A, DeMarines J, Grinspoon D, Reitz G, Prats B, Atlaskin E, Genzer M, Harri AM, Haukka H, Kahanpaa H, Kauhanen J, Paton M, Polkko J, Schmidt W, Siili T, Fabre C, Wray J, Wilhelm MB, Poitrasson F, Patel K, Gorevan S, Indyk S, Paulsen G, Bish D, Gondet B, Langevin Y, Geffroy C, Baratoux D, Berger G, Cros A, d'Uston C, Forni O, Gasnault O, Lasue J, Lee QM, Meslin PY, Pallier E, Parot Y, Pinet P, Schroder S, Toplis M, Lewin E, Brunner W, Heydari E, Achilles C, Sutter B, Cabane M, Coscia D, Szopa C, Robert F, Sautter V, Le Mouelic S, Nachon M, Buch A, Stalport F, Coll P, Francois P, Raulin F, Teinturier S, Cameron J, Clegg S, Cousin A, DeLapp D, Dingler R, Jackson RS, Johnstone S, Lanza N, Little C, Nelson T, Williams RB, Jones A, Kirkland L, Baker B, Cantor B, Caplinger M, Davis S, Duston B, Fay D, Harker D, Herrera P, Jensen E, Kennedy MR, Krezoski G, Krysak D, Lipkaman L, McCartney E, McNair S, Nixon B, Posiolova L, Ravine M, Salamon A, Saper L, Stoiber K, Supulver K, Van Beek J, Van Beek T, Zimdar R, French KL, Iagnemma K, Miller K, Goesmann F, Goetz W, Hviid S, Johnson M, Lefavor M, Lyness E, Breves E, Dyar MD, Fassett C, Edwards L, Haberle R, Hoehler T, Hollingsworth J, Kahre M, Keely L, McKay C, Bleacher L, Brinckerhoff W, Choi D, Dworkin JP, Floyd M, Freissinet C, Garvin J, Glavin D, Harpold D, Martin DK, McAdam A, Pavlov A, Raaen E, Smith MD, Stern J, Tan F, Trainer M, Posner A, Voytek M, Aubrey A, Behar A, Blaney D, Brinza D, Christensen L, DeFlores L, Feldman J, Feldman S, Flesch G, Jun I, Keymeulen D, Mischna M, Morookian JM, Pavri B, Schoppers M, Sengstacken A, Simmonds JJ, Spanovich N, Juarez MDLT, Webster CR, Yen A, Archer PD, Cucinotta F, Jones JH, Morris RV, Niles P, Rampe E, Nolan T, Fisk M, Radziemski L, Barraclough B, Bender S, Berman D, Dobrea EN, Tokar R, Cleghorn T, Huntress W, Manhes G, Hudgins J, Olson T, Stewart N, Sarrazin P, Vicenzi E, Bullock M, Ehresmann B, Hamilton V, Hassler D, Peterson J, Rafkin S, Zeitlin C, Fedosov F, Golovin D, Karpushkina N, Kozyrev A, Litvak M, Malakhov A, Mitrofanov I, Mokrousov M, Nikiforov S, Prokhorov V, Sanin A, Tretyakov V, Varenikov A, Vostrukhin A, Kuzmin R, Clark B, Wolff M, Botta O, Drake D, Bean K, Lemmon M, Schwenzer SP, Lee EM, Sucharski R, Hernandez MADP, Avalos JJB, Ramos M, Kim MH, Malespin C, Plante I, Muller JP, Navarro-Gonzalez R, Ewing R, Boynton W, Downs R, Fitzgibbon M, Harshman K, Morrison S, Kortmann O, Williams A, Lugmair G, Wilson MA, Jakosky B, Balic-Zunic T, Frydenvang J, Jensen JK, Kinch K, Koefoed A, Madsen MB, Stipp SLS, Boyd N, Campbell JL, Perrett G, Pradler I, VanBommel S, Jacob S, Owen T, Savijarvi H, Boehm E, Bottcher S, Burmeister S, Guo J, Kohler J, Garcia CM, Mueller-Mellin R, Wimmer-Schweingruber R, Bridges JC, McConnochie T, Benna M, Franz H, Bower H, Brunner A, Blau H, Boucher T, Carmosino M, Atreya S, Elliott H, Halleaux D, Renno N, Wong M, Pepin R, Elliott B, Spray J, Thompson L, Gordon S, Ollila A, Williams J, Vasconcelos P, Bentz J, Nealson K, Popa R, Moersch J, Tate C, Day M, Francis R, McCullough E, Cloutis E, ten Kate IL, Scholes D, Slavney S, Stein T, Ward J, Berger J, Moores JE. A Habitable Fluvio-Lacustrine Environment at Yellowknife Bay, Gale Crater, Mars. Science 2013; 343:1242777. [DOI: 10.1126/science.1242777] [Citation(s) in RCA: 578] [Impact Index Per Article: 52.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Westall F. Microbial Scale Habitability on Mars. HABITABILITY OF OTHER PLANETS AND SATELLITES 2013. [DOI: 10.1007/978-94-007-6546-7_11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Weitz CM, Noe Dobrea EZ, Lane MD, Knudson AT. Geologic relationships between gray hematite, sulfates, and clays in Capri Chasma. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012je004092] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Desulfohalophilus alkaliarsenatis gen. nov., sp. nov., an extremely halophilic sulfate- and arsenate-respiring bacterium from Searles Lake, California. Extremophiles 2012; 16:727-42. [PMID: 22744231 PMCID: PMC3432211 DOI: 10.1007/s00792-012-0468-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 06/14/2012] [Indexed: 12/03/2022]
Abstract
A haloalkaliphilic sulfate-respiring bacterium, strain SLSR-1, was isolated from a lactate-fed stable enrichment culture originally obtained from the extreme environment of Searles Lake, California. The isolate proved capable of growth via sulfate-reduction over a broad range of salinities (125–330 g/L), although growth was slowest at salt-saturation. Strain SLSR-1 was also capable of growth via dissimilatory arsenate-reduction and displayed an even broader range of salinity tolerance (50–330 g/L) when grown under these conditions. Strain SLSR-1 could also grow via dissimilatory nitrate reduction to ammonia. Growth experiments in the presence of high borate concentrations indicated a greater sensitivity of sulfate-reduction than arsenate-respiration to this naturally abundant anion in Searles Lake. Strain SLSR-1 contained genes involved in both sulfate-reduction (dsrAB) and arsenate respiration (arrA). Amplicons of 16S rRNA gene sequences obtained from DNA extracted from Searles Lake sediment revealed the presence of close relatives of strain SLSR-1 as part of the flora of this ecosystem despite the fact that sulfate-reduction activity could not be detected in situ. We conclude that strain SLSR-1 can only achieve growth via arsenate-reduction under the current chemical conditions prevalent at Searles Lake. Strain SLSR-1 is a deltaproteobacterium in the family Desulfohalobiacea of anaerobic, haloalkaliphilic bacteria, for which we propose the name Desulfohalophilus alkaliarsenatis gen. nov., sp. nov.
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Kereszturi A. Review of wet environment types on Mars with focus on duration and volumetric issues. ASTROBIOLOGY 2012; 12:586-600. [PMID: 22794300 DOI: 10.1089/ast.2011.0686] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The astrobiological significance of certain environment types on Mars strongly depends on the temperature, duration, and chemistry of liquid water that was present there in the past. Recent works have focused on the identification of signs of ancient water on Mars, as it is more difficult to estimate the above-mentioned parameters. In this paper, two important factors are reviewed, the duration and the volume of water at different environment types on past and present Mars. Using currently available information, we can only roughly estimate these values, but as environment types show characteristic differences in this respect, it is worth comparing them and the result may have importance for research in astrobiology. Impact-induced and geothermal hydrothermal systems, lakes, and valley networks were in existence on Mars over the course of from 10(2) to 10(6) years, although they would have experienced substantially different temperature regimes. Ancient oceans, as well as water in outflow channels and gullies, and at the microscopic scale as interfacial water layers, would have had inherently different times of duration and overall volume: oceans may have endured from 10(4) to 10(6) years, while interfacial water would have had the smallest volume and residence time of liquid phase on Mars. Martian wet environments with longer residence times of liquid water are believed to have existed for that amount of time necessary for life to develop on Earth between the Late Heavy Bombardment and the age of the earliest fossil record. The results of this review show the necessity for more detailed analysis of conditions within geothermal heat-induced systems to reconstruct the conditions during weathering and mineral alteration, as well as to search for signs of reoccurring wet periods in ancient crater lakes.
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Affiliation(s)
- Akos Kereszturi
- Konkoly Thege Miklos Astronomical Institute, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, Budapest, Hungary.
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Squyres SW, Arvidson RE, Bell JF, Calef F, Clark BC, Cohen BA, Crumpler LA, de Souza PA, Farrand WH, Gellert R, Grant J, Herkenhoff KE, Hurowitz JA, Johnson JR, Jolliff BL, Knoll AH, Li R, McLennan SM, Ming DW, Mittlefehldt DW, Parker TJ, Paulsen G, Rice MS, Ruff SW, Schroder C, Yen AS, Zacny K. Ancient Impact and Aqueous Processes at Endeavour Crater, Mars. Science 2012; 336:570-6. [DOI: 10.1126/science.1220476] [Citation(s) in RCA: 151] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Planning for Mars returned sample science: final report of the MSR End-to-End International Science Analysis Group (E2E-iSAG). ASTROBIOLOGY 2012; 12:175-230. [PMID: 22468886 DOI: 10.1089/ast.2011.0805] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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