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Macey MC, Ramkissoon NK, Cogliati S, Toubes-Rodrigo M, Stephens BP, Kucukkilic-Stephens E, Schwenzer SP, Pearson VK, Preston LJ, Olsson-Francis K. Habitability and Biosignature Formation in Simulated Martian Aqueous Environments. ASTROBIOLOGY 2023; 23:144-154. [PMID: 36577028 DOI: 10.1089/ast.2021.0197] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Water present on early Mars is often assumed to have been habitable. In this study, experiments were performed to investigate the habitability of well-defined putative martian fluids and to identify the accompanying potential formation of biosignatures. Simulated martian environments were developed by combining martian fluid and regolith simulants based on the chemistry of the Rocknest sand shadow at Gale Crater. The simulated chemical environment was inoculated with terrestrial anoxic sediment from the Pyefleet mudflats (United Kingdom). These enrichments were cultured for 28 days and subsequently subcultured seven times to ensure that the microbial community was solely grown on the defined, simulated chemistry. The impact of the simulated chemistries on the microbial community was assessed by cell counts and sequencing of 16S rRNA gene profiles. Associated changes to the fluid and precipitate chemistries were established by using ICP-OES, IC, FTIR, and NIR. The fluids were confirmed as habitable, with the enriched microbial community showing a reduction in abundance and diversity over multiple subcultures relating to the selection of specific metabolic groups. The final community comprised sulfate-reducing, acetogenic, and other anaerobic and fermentative bacteria. Geochemical characterization and modeling of the simulant and fluid chemistries identified clear differences between the biotic and abiotic experiments. These differences included the elimination of sulfur owing to the presence of sulfate-reducing bacteria and more general changes in pH associated with actively respiring cells that impacted the mineral assemblages formed. This study confirmed that a system simulating the fluid chemistry of Gale Crater could support a microbial community and that variation in chemistries under biotic and abiotic conditions can be used to inform future life-detection missions.
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Affiliation(s)
- Michael C Macey
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Nisha K Ramkissoon
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Simone Cogliati
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Mario Toubes-Rodrigo
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Ben P Stephens
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Ezgi Kucukkilic-Stephens
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Susanne P Schwenzer
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Victoria K Pearson
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Louisa J Preston
- Mullard Space Science Laboratory, Department of Space and Climate Physics, University College London, London, United Kingdom
| | - Karen Olsson-Francis
- AstrobiologyOU, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
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2
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Weingarten EA, Zee PC, Jackson CR. Microbial Communities in Saltpan Sediments Show Tolerance to Mars Analog Conditions, but Susceptibility to Chloride and Perchlorate Toxicity. ASTROBIOLOGY 2022; 22:838-850. [PMID: 35731161 PMCID: PMC9464085 DOI: 10.1089/ast.2021.0132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 02/28/2022] [Indexed: 06/15/2023]
Abstract
Brines at or near the surface of present-day Mars are a potential explanation for seasonally recurring dark streaks on the walls of craters, termed recurring slope lineae (RSL). Deliquescence and freezing point depression are possible drivers of brine stability, attributable to the high salinity observed in martian regolith including chlorides and perchlorates. Investigation of life, which may inhabit RSL, and the cellular mechanisms necessary for survival, must consider the tolerance of highly variable hydration, freeze-thaw cycles, and high osmolarity in addition to the anaerobic, oligotrophic, and irradiated environment. We propose the saltpan, an ephemeral, hypersaline wetland as an analogue for putative RSL hydrology. Saltpan sediment archaeal and bacterial communities showed tolerance of the Mars-analogous atmosphere, hydration, minerology, salinity, and temperature. Although active growth and a shift to well-adapted taxa were observed, susceptibility to low-concentration chloride and perchlorate addition suggested that such a composition was insufficient for beneficial water retention relative to added salt stress.
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Affiliation(s)
- Eric A. Weingarten
- Department of Biology, University of Mississippi, University, Mississippi, USA
- U.S. Army Engineer Research and Development Center, Vicksburg, Mississippi, USA
| | - Peter C. Zee
- Department of Biology, University of Mississippi, University, Mississippi, USA
| | - Colin R. Jackson
- Department of Biology, University of Mississippi, University, Mississippi, USA
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3
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Santomartino R, Zea L, Cockell CS. The smallest space miners: principles of space biomining. Extremophiles 2022; 26:7. [PMID: 34993644 PMCID: PMC8739323 DOI: 10.1007/s00792-021-01253-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 12/09/2021] [Indexed: 12/03/2022]
Abstract
As we aim to expand human presence in space, we need to find viable approaches to achieve independence from terrestrial resources. Space biomining of the Moon, Mars and asteroids has been indicated as one of the promising approaches to achieve in-situ resource utilization by the main space agencies. Structural and expensive metals, essential mineral nutrients, water, oxygen and volatiles could be potentially extracted from extraterrestrial regolith and rocks using microbial-based biotechnologies. The use of bioleaching microorganisms could also be applied to space bioremediation, recycling of waste and to reinforce regenerative life support systems. However, the science around space biomining is still young. Relevant differences between terrestrial and extraterrestrial conditions exist, including the rock types and ores available for mining, and a direct application of established terrestrial biomining techniques may not be a possibility. It is, therefore, necessary to invest in terrestrial and space-based research of specific methods for space applications to learn the effects of space conditions on biomining and bioremediation, expand our knowledge on organotrophic and community-based bioleaching mechanisms, as well as on anaerobic biomining, and investigate the use of synthetic biology to overcome limitations posed by the space environments.
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Affiliation(s)
- Rosa Santomartino
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3FD, UK.
| | - Luis Zea
- BioServe Space Technologies, University of Colorado Boulder, Boulder, CO, USA
| | - Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3FD, UK
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4
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Kelbrick M, Oliver JAW, Ramkissoon NK, Dugdale A, Stephens BP, Kucukkilic-Stephens E, Schwenzer SP, Antunes A, Macey MC. Microbes from Brine Systems with Fluctuating Salinity Can Thrive under Simulated Martian Chemical Conditions. Life (Basel) 2021; 12:life12010012. [PMID: 35054406 PMCID: PMC8781782 DOI: 10.3390/life12010012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/15/2021] [Accepted: 12/18/2021] [Indexed: 12/01/2022] Open
Abstract
The waters that were present on early Mars may have been habitable. Characterising environments analogous to these waters and investigating the viability of their microbes under simulated martian chemical conditions is key to developing hypotheses on this habitability and potential biosignature formation. In this study, we examined the viability of microbes from the Anderton Brine Springs (United Kingdom) under simulated martian chemistries designed to simulate the chemical conditions of water that may have existed during the Hesperian. Associated changes in the fluid chemistries were also tested using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The tested Hesperian fluid chemistries were shown to be habitable, supporting the growth of all of the Anderton Brine Spring isolates. However, inter and intra-generic variation was observed both in the ability of the isolates to tolerate more concentrated fluids and in their impact on the fluid chemistry. Therefore, whilst this study shows microbes from fluctuating brines can survive and grow in simulated martian water chemistry, further investigations are required to further define the potential habitability under past martian conditions.
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Affiliation(s)
- Matthew Kelbrick
- Biology Department, Edge Hill University, Ormskirk L39 4QP, UK;
- Department of Evolution, Ecology and Behaviour, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L69 3GJ, UK
- Correspondence: (M.K.); (M.C.M.)
| | | | - Nisha K. Ramkissoon
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (S.P.S.)
| | - Amy Dugdale
- AstrobiologyOU, School of Physical Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes W23 F2H6, UK;
- Biology Department, Maynooth University, Maynooth, W23 F2H6 Kildare, Ireland
| | - Ben P. Stephens
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (S.P.S.)
| | - Ezgi Kucukkilic-Stephens
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (S.P.S.)
| | - Susanne P. Schwenzer
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (S.P.S.)
| | - André Antunes
- State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology (MUST), Macau, China;
- China National Space Administration (CNSA), Macau Center for Space Exploration and Science, Macau, China
| | - Michael C. Macey
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (S.P.S.)
- Correspondence: (M.K.); (M.C.M.)
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5
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Cockell CS, Santomartino R, Finster K, Waajen AC, Nicholson N, Loudon CM, Eades LJ, Moeller R, Rettberg P, Fuchs FM, Van Houdt R, Leys N, Coninx I, Hatton J, Parmitano L, Krause J, Koehler A, Caplin N, Zuijderduijn L, Mariani A, Pellari S, Carubia F, Luciani G, Balsamo M, Zolesi V, Ochoa J, Sen P, Watt JAJ, Doswald-Winkler J, Herová M, Rattenbacher B, Wadsworth J, Everroad RC, Demets R. Microbially-Enhanced Vanadium Mining and Bioremediation Under Micro- and Mars Gravity on the International Space Station. Front Microbiol 2021; 12:641387. [PMID: 33868198 PMCID: PMC8047202 DOI: 10.3389/fmicb.2021.641387] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 03/04/2021] [Indexed: 11/30/2022] Open
Abstract
As humans explore and settle in space, they will need to mine elements to support industries such as manufacturing and construction. In preparation for the establishment of permanent human settlements across the Solar System, we conducted the ESA BioRock experiment on board the International Space Station to investigate whether biological mining could be accomplished under extraterrestrial gravity conditions. We tested the hypothesis that the gravity (g) level influenced the efficacy with which biomining could be achieved from basalt, an abundant material on the Moon and Mars, by quantifying bioleaching by three different microorganisms under microgravity, simulated Mars and Earth gravitational conditions. One element of interest in mining is vanadium (V), which is added to steel to fabricate high strength, corrosion-resistant structural materials for buildings, transportation, tools and other applications. The results showed that Sphingomonas desiccabilis and Bacillus subtilis enhanced the leaching of vanadium under the three gravity conditions compared to sterile controls by 184.92 to 283.22%, respectively. Gravity did not have a significant effect on mean leaching, thus showing the potential for biomining on Solar System objects with diverse gravitational conditions. Our results demonstrate the potential to use microorganisms to conduct elemental mining and other bioindustrial processes in space locations with non-1 × g gravity. These same principles apply to extraterrestrial bioremediation and elemental recycling beyond Earth.
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Affiliation(s)
- Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Rosa Santomartino
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Kai Finster
- Department of Biology - Microbiology, Aarhus University, Aarhus, Denmark
| | - Annemiek C Waajen
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Natasha Nicholson
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Claire-Marie Loudon
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Lorna J Eades
- School of Chemistry, University of Edinburgh, Edinburgh, United Kingdom
| | - Ralf Moeller
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Köln, Germany
| | - Petra Rettberg
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Köln, Germany
| | - Felix M Fuchs
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Köln, Germany.,Institute of Electrical Engineering and Plasma Technology, Faculty of Electrical Engineering and Information Sciences, Ruhr University Bochum, Bochum, Germany
| | - Rob Van Houdt
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | - Natalie Leys
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | - Ilse Coninx
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | | | | | | | | | | | | | | | | | | | | | | | | | - Jon Ochoa
- ESTEC, Noordwijk, Netherlands.,Space Application Services NV/SA, Noordwijk, Netherlands
| | - Pia Sen
- Earth and Environmental Sciences Department, Rutgers University, Newark, NJ, United States
| | - James A J Watt
- School of Geosciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Jeannine Doswald-Winkler
- BIOTESC, Hochschule Luzern Technik & Architektur, Lucerne School of Engineering and Architecture, Hergiswil, Switzerland
| | - Magdalena Herová
- BIOTESC, Hochschule Luzern Technik & Architektur, Lucerne School of Engineering and Architecture, Hergiswil, Switzerland
| | - Bernd Rattenbacher
- BIOTESC, Hochschule Luzern Technik & Architektur, Lucerne School of Engineering and Architecture, Hergiswil, Switzerland
| | - Jennifer Wadsworth
- Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, United States
| | - R Craig Everroad
- Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, United States
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6
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Orevi T, Kashtan N. Life in a Droplet: Microbial Ecology in Microscopic Surface Wetness. Front Microbiol 2021; 12:655459. [PMID: 33927707 PMCID: PMC8076497 DOI: 10.3389/fmicb.2021.655459] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 03/19/2021] [Indexed: 12/16/2022] Open
Abstract
While many natural and artificial surfaces may appear dry, they are in fact covered by thin liquid films and microdroplets invisible to the naked eye known as microscopic surface wetness (MSW). Central to the formation and the retention of MSW are the deliquescent properties of hygroscopic salts that prevent complete drying of wet surfaces or that drive the absorption of water until dissolution when the relative humidity is above a salt-specific level. As salts are ubiquitous, MSW occurs in many microbial habitats, such as soil, rocks, plant leaf, and root surfaces, the built environment, and human and animal skin. While key properties of MSW, including very high salinity and segregation into droplets, greatly affect microbial life therein, it has been scarcely studied, and systematic studies are only in their beginnings. Based on recent findings, we propose that the harsh micro-environment that MSW imposes, which is very different from bulk liquid, affects key aspects of bacterial ecology including survival traits, antibiotic response, competition, motility, communication, and exchange of genetic material. Further research is required to uncover the fundamental principles that govern microbial life and ecology in MSW. Such research will require multidisciplinary science cutting across biology, physics, and chemistry, while incorporating approaches from microbiology, genomics, microscopy, and computational modeling. The results of such research will be critical to understand microbial ecology in vast terrestrial habitats, affecting global biogeochemical cycles, as well as plant, animal, and human health.
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Affiliation(s)
- Tomer Orevi
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food, and Environment, Institute of Environmental Sciences, Hebrew University, Rehovot, Israel
| | - Nadav Kashtan
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food, and Environment, Institute of Environmental Sciences, Hebrew University, Rehovot, Israel
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7
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Gault S, Cockell CS. Perchlorate Salts Exert a Dominant, Deleterious Effect on the Structure, Stability, and Activity of α-Chymotrypsin. ASTROBIOLOGY 2021; 21:405-412. [PMID: 33784200 DOI: 10.1089/ast.2020.2223] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The presence of perchlorate ions on Mars raises the question of how these ions influence the biochemistry of any contaminant life introduced into the martian environment, or what selection pressures perchlorate ions exert on any environment that contains these ions, such as the Atacama Desert. In this study, we investigated the structure, stability, and enzyme activity of the model enzyme α-chymotrypsin in the presence of five Mars relevant salts, MgSO4, MgCl2, Mg(ClO4)2, Ca(ClO4)2, and NaClO4. We found that all the perchlorate salts reduced the enzyme activity of α-chymotrypsin in a concentration-dependent manner, with Mg(ClO4)2 and Ca(ClO4)2 having the greatest effect. This observation extends to our structural studies, which show that 1 M Mg(ClO4)2 and Ca(ClO4)2 greatly alter the tertiary structural environment of α-chymotrypsin. We also found that all the perchlorate salts assayed reduced the melting temperature of α-chymotrypsin, whereas the sulfate and chloride salts were able to increase the protein melting temperature. We also demonstrated that a brine containing both perchlorate and sulfate ions exerts the same deleterious effects on α-chymotrypsin's melting temperature and enzyme activity as that of a perchlorate-only brine. This suggests that the perchlorate salts exert a dominant, deleterious effect on protein biochemistry. These results indicate that although perchlorate salts are beneficial to the presence of liquid water due to low eutectic points, they also hamper the habitability of their own environment. Life in such brines would, therefore, have to adapt its cellular machinery to the perchlorate ion's presence or find a way of excluding it from said machinery.
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Affiliation(s)
- Stewart Gault
- Centre for Astrobiology, SUPA School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Charles S Cockell
- Centre for Astrobiology, SUPA School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
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8
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Smith HB, Drew A, Malloy JF, Walker SI. Seeding Biochemistry on Other Worlds: Enceladus as a Case Study. ASTROBIOLOGY 2021; 21:177-190. [PMID: 33064954 PMCID: PMC7876360 DOI: 10.1089/ast.2019.2197] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 09/07/2020] [Indexed: 06/11/2023]
Abstract
The Solar System is becoming increasingly accessible to exploration by robotic missions to search for life. However, astrobiologists currently lack well-defined frameworks to quantitatively assess the chemical space accessible to life in these alien environments. Such frameworks will be critical for developing concrete predictions needed for future mission planning, both to determine the potential viability of life on other worlds and to anticipate the molecular biosignatures that life could produce. Here, we describe how uniting existing methods provides a framework to study the accessibility of biochemical space across diverse planetary environments. Our approach combines observational data from planetary missions with genomic data catalogued from across Earth and analyzed using computational methods from network theory. To demonstrate this, we use 307 biochemical networks generated from genomic data collected across Earth and "seed" these networks with molecules confirmed to be present on Saturn's moon Enceladus. By expanding through known biochemical reaction space starting from these seed compounds, we are able to determine which products of Earth's biochemistry are, in principle, reachable from compounds available in the environment on Enceladus, and how this varies across different examples of life from Earth (organisms, ecosystems, planetary-scale biochemistry). While we find that none of the 307 prokaryotes analyzed meet the threshold for viability, the reaction space covered by this process can provide a map of possible targets for detection of Earth-like life on Enceladus, as well as targets for synthetic biology approaches to seed life on Enceladus. In cases where biochemistry is not viable because key compounds are missing, we identify the environmental precursors required to make it viable, thus providing a set of compounds to prioritize for detection in future planetary exploration missions aimed at assessing the ability of Enceladus to sustain Earth-like life or directed panspermia.
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Affiliation(s)
- Harrison B. Smith
- School of Earth and Space Exploration, Arizona State University, Tempe, Arizona, USA
| | - Alexa Drew
- School of Earth and Space Exploration, Arizona State University, Tempe, Arizona, USA
| | - John F. Malloy
- School of Earth and Space Exploration, Arizona State University, Tempe, Arizona, USA
| | - Sara Imari Walker
- School of Earth and Space Exploration, Arizona State University, Tempe, Arizona, USA
- ASU-SFI Center for Biosocial Complex Systems, Arizona State University, Tempe, Arizona, USA
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, Arizona, USA
- Santa Fe Institute, Santa Fe, New Mexico, USA
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9
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Santomartino R, Waajen AC, de Wit W, Nicholson N, Parmitano L, Loudon CM, Moeller R, Rettberg P, Fuchs FM, Van Houdt R, Finster K, Coninx I, Krause J, Koehler A, Caplin N, Zuijderduijn L, Zolesi V, Balsamo M, Mariani A, Pellari SS, Carubia F, Luciani G, Leys N, Doswald-Winkler J, Herová M, Wadsworth J, Everroad RC, Rattenbacher B, Demets R, Cockell CS. No Effect of Microgravity and Simulated Mars Gravity on Final Bacterial Cell Concentrations on the International Space Station: Applications to Space Bioproduction. Front Microbiol 2020; 11:579156. [PMID: 33154740 PMCID: PMC7591705 DOI: 10.3389/fmicb.2020.579156] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/09/2020] [Indexed: 12/24/2022] Open
Abstract
Microorganisms perform countless tasks on Earth and they are expected to be essential for human space exploration. Despite the interest in the responses of bacteria to space conditions, the findings on the effects of microgravity have been contradictory, while the effects of Martian gravity are nearly unknown. We performed the ESA BioRock experiment on the International Space Station to study microbe-mineral interactions in microgravity, simulated Mars gravity and simulated Earth gravity, as well as in ground gravity controls, with three bacterial species: Sphingomonas desiccabilis, Bacillus subtilis, and Cupriavidus metallidurans. To our knowledge, this was the first experiment to study simulated Martian gravity on bacteria using a space platform. Here, we tested the hypothesis that different gravity regimens can influence the final cell concentrations achieved after a multi-week period in space. Despite the different sedimentation rates predicted, we found no significant differences in final cell counts and optical densities between the three gravity regimens on the ISS. This suggests that possible gravity-related effects on bacterial growth were overcome by the end of the experiment. The results indicate that microbial-supported bioproduction and life support systems can be effectively performed in space (e.g., Mars), as on Earth.
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Affiliation(s)
- Rosa Santomartino
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Annemiek C Waajen
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Wessel de Wit
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Natasha Nicholson
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Luca Parmitano
- European Space Research and Technology Centre (ESTEC), Noordwijk, Netherlands
| | - Claire-Marie Loudon
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Ralf Moeller
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne (Köln), Germany
| | - Petra Rettberg
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne (Köln), Germany
| | - Felix M Fuchs
- Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne (Köln), Germany
| | - Rob Van Houdt
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | - Kai Finster
- Department of Biology - Microbiology, Aarhus University, Aarhus C, Denmark
| | - Ilse Coninx
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | - Jutta Krause
- European Space Research and Technology Centre (ESTEC), Noordwijk, Netherlands
| | - Andrea Koehler
- European Space Research and Technology Centre (ESTEC), Noordwijk, Netherlands
| | - Nicol Caplin
- European Space Research and Technology Centre (ESTEC), Noordwijk, Netherlands
| | - Lobke Zuijderduijn
- European Space Research and Technology Centre (ESTEC), Noordwijk, Netherlands
| | | | | | | | | | | | | | - Natalie Leys
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium
| | | | - Magdalena Herová
- BIOTESC, Hochschule Luzern Technik und Architektur, Hergiswil, Switzerland
| | - Jennifer Wadsworth
- Exobiology Branch, NASA Ames Research Center, Moffet Field, CA, United States
| | - R Craig Everroad
- Exobiology Branch, NASA Ames Research Center, Moffet Field, CA, United States
| | - Bernd Rattenbacher
- BIOTESC, Hochschule Luzern Technik und Architektur, Hergiswil, Switzerland
| | - René Demets
- European Space Research and Technology Centre (ESTEC), Noordwijk, Netherlands
| | - Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
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10
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Gault S, Jaworek MW, Winter R, Cockell CS. High pressures increase α-chymotrypsin enzyme activity under perchlorate stress. Commun Biol 2020; 3:550. [PMID: 33009512 PMCID: PMC7532203 DOI: 10.1038/s42003-020-01279-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 09/10/2020] [Indexed: 11/16/2022] Open
Abstract
Deep subsurface environments can harbour high concentrations of dissolved ions, yet we know little about how this shapes the conditions for life. We know even less about how the combined effects of high pressure influence the way in which ions constrain the possibilities for life. One such ion is perchlorate, which is found in extreme environments on Earth and pervasively on Mars. We investigated the interactions of high pressure and high perchlorate concentrations on enzymatic activity. We demonstrate that high pressures increase α-chymotrypsin enzyme activity even in the presence of high perchlorate concentrations. Perchlorate salts were shown to shift the folded α-chymotrypsin phase space to lower temperatures and pressures. The results presented here may suggest that high pressures increase the habitability of environments under perchlorate stress. Therefore, deep subsurface environments that combine these stressors, potentially including the subsurface of Mars, may be more habitable than previously thought. Gault et al. show that high pressures increase α-chymotrypsin enzyme activity in the presence of high perchlorate concentrations. These perchlorate salts shift the folded enzyme phase space to lower temperatures and pressure and may move the optimum enzyme activity towards lower temperatures in addition to higher pressures, which has implications for Martian habitability.
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Affiliation(s)
- Stewart Gault
- UK Centre for Astrobiology, SUPA School of Physics and Astronomy, University of Edinburgh, James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, UK.
| | - Michel W Jaworek
- Faculty of Chemistry and Chemical Biology, Physical Chemistry I - Biophysical Chemistry, TU Dortmund University, Otto-Hahn-Str. 4a, D-44227, Dortmund, Germany
| | - Roland Winter
- Faculty of Chemistry and Chemical Biology, Physical Chemistry I - Biophysical Chemistry, TU Dortmund University, Otto-Hahn-Str. 4a, D-44227, Dortmund, Germany
| | - Charles S Cockell
- UK Centre for Astrobiology, SUPA School of Physics and Astronomy, University of Edinburgh, James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, UK
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11
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Cockell CS, McLean CM, Perera L, Aka S, Stevens A, Dickinson AW. Growth of Non-Halophilic Bacteria in the Sodium-Magnesium-Sulfate-Chloride Ion System: Unravelling the Complexities of Ion Interactions in Terrestrial and Extraterrestrial Aqueous Environments. ASTROBIOLOGY 2020; 20:944-955. [PMID: 32434375 DOI: 10.1089/ast.2019.2092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Motivated by an interest in understanding the habitability of aqueous environments on Earth and in extraterrestrial settings, this study investigated the influence of ions in an artificial sodium-magnesium-sulfate-chloride ion system on the growth parameters (lag phase, growth rate, and final cell concentration) of bacteria. These four ions, in different combinations, are key components of many aqueous environments on Earth and elsewhere. We investigated non-halophilic bacteria deliberately to remove the bias of prior adaptations to high concentrations of selected ions so that we could compare the effects of different ions. We tested the hypothesis that water activity determined the growth parameters independent of the ion types. Neither water activity or ionic strength alone could predict growth. However, when ionic strengths were matched, many differences in growth parameters could be explained by the water activity. We suggest that species-specific effects (caused by differences in biochemical and physiological influences), the role of individual ions in cellular processes, and potentially the chaotropicity and kosmotropicity of solutions influenced the growth. Our data show that although extreme combinations of these ions allow for general predictions on the habitability of extraterrestrial aqueous environments, a complex interplay of ionic effects influences the growth and thus the adaptations required for given ion combinations. The data also show that an accurate quantification of the habitability of ocean worlds, such as Europa and Enceladus, can only be made when samples are obtained from these water bodies and the ion combinations are determined.
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Affiliation(s)
- Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Claire-Marie McLean
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Liam Perera
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Salomé Aka
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Adam Stevens
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Andrew W Dickinson
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
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12
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Stevens AH, Cockell CS. A Systematic Study of the Limits of Life in Mixed Ion Solutions: Physicochemical Parameters Do Not Predict Habitability. Front Microbiol 2020; 11:1478. [PMID: 32670258 PMCID: PMC7332579 DOI: 10.3389/fmicb.2020.01478] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/08/2020] [Indexed: 11/13/2022] Open
Abstract
This study investigated what defines the limits of life in mixed ion solutions. Better understanding these limits should allow us to better predict the habitability of extreme environments on the Earth and extraterrestrial environments. We systematically examined the response of Bacillus subtilis, a well characterized non-halophile model organism, to a range of solutions made from single and mixed salts up to their solubility limits and measured at what concentration growth was arrested, specifically exploring Na, Mg, and Ca cations and Cl, SO4, and ClO4 anions. We measured the physicochemical properties of the solutions to identify which properties correlated with the limits of growth. Individual salts imposed a growth limit specific to the combination of cation and anion, although we generally observe that chloride salts allow growth at lower water activity than sulfate salts, with perchlorate restricting growth even at the highest measured water activity. Growth was limited at a wide range of ionic strength, with no apparently correlation. Despite the theoretically counteracting disordering effects (chaotropic) of perchlorates and ordering effects (kosmotropic) effects of sulfates, when these salts were combined they instead additively narrowed the window for growth in both the Na and Mg cation systems, in the same manner as the combined effects of two chaotropic Ca salts. Our results imply that away from hard limits that might be imposed by physicochemical properties such as water activity, ionic strength or chaotropicity in highly concentrated brines, these properties do not set the limits of life. Instead these limits are highly specific to the salts and organisms in question. This specificity means that the habitability of extreme environments cannot be predicted, even with accurate measurements of the physicochemical conditions present.
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Affiliation(s)
- Adam H. Stevens
- UK Centre for Astrobiology, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, United Kingdom
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13
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Taubner RS, Olsson-Francis K, Vance SD, Ramkissoon NK, Postberg F, de Vera JP, Antunes A, Camprubi Casas E, Sekine Y, Noack L, Barge L, Goodman J, Jebbar M, Journaux B, Karatekin Ö, Klenner F, Rabbow E, Rettberg P, Rückriemen-Bez T, Saur J, Shibuya T, Soderlund KM. Experimental and Simulation Efforts in the Astrobiological Exploration of Exooceans. SPACE SCIENCE REVIEWS 2020; 216:9. [PMID: 32025060 PMCID: PMC6977147 DOI: 10.1007/s11214-020-0635-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 01/06/2020] [Indexed: 05/05/2023]
Abstract
The icy satellites of Jupiter and Saturn are perhaps the most promising places in the Solar System regarding habitability. However, the potential habitable environments are hidden underneath km-thick ice shells. The discovery of Enceladus' plume by the Cassini mission has provided vital clues in our understanding of the processes occurring within the interior of exooceans. To interpret these data and to help configure instruments for future missions, controlled laboratory experiments and simulations are needed. This review aims to bring together studies and experimental designs from various scientific fields currently investigating the icy moons, including planetary sciences, chemistry, (micro-)biology, geology, glaciology, etc. This chapter provides an overview of successful in situ, in silico, and in vitro experiments, which explore different regions of interest on icy moons, i.e. a potential plume, surface, icy shell, water and brines, hydrothermal vents, and the rocky core.
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Affiliation(s)
- Ruth-Sophie Taubner
- Archaea Biology and Ecogenomics Division, University of Vienna, Vienna, Austria
| | | | | | | | | | | | - André Antunes
- State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau SAR, China
| | | | | | - Lena Noack
- Freie Universität Berlin, Berlin, Germany
| | | | | | | | | | | | | | - Elke Rabbow
- German Aerospace Center (DLR), Cologne, Germany
| | | | | | | | - Takazo Shibuya
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
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14
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Cosciotti B, Balbi A, Ceccarelli A, Fagliarone C, Mattei E, Lauro SE, Di Paolo F, Pettinelli E, Billi D. Survivability of Anhydrobiotic Cyanobacteria in Salty Ice: Implications for the Habitability of Icy Worlds. Life (Basel) 2019; 9:life9040086. [PMID: 31766612 PMCID: PMC6958388 DOI: 10.3390/life9040086] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 11/14/2019] [Accepted: 11/19/2019] [Indexed: 11/16/2022] Open
Abstract
Two anhydrobiotic strains of the cyanobacterium Chroococcidiopsis, namely CCMEE 029 and CCMEE 171, isolated from the Negev Desert in Israel and from the Dry Valleys in Antarctica, were exposed to salty-ice simulations. The aim of the experiment was to investigate the cyanobacterial capability to survive under sub-freezing temperatures in samples simulating the environment of icy worlds. The two strains were mixed with liquid solutions having sub-eutectic concentration of Na2SO4, MgSO4 and NaCl, then frozen down to different final temperatures (258 K, 233 K and 203 K) in various experimental runs. Both strains survived the exposure to 258 K in NaCl solution, probably as they migrated in the liquid veins between ice grain boundaries. However, they also survived at 258 K in Na2SO4 and MgSO4-salty-ice samples-that is, a temperature well below the eutectic temperature of the solutions, where liquid veins should not exist anymore. Moreover, both strains survived the exposure at 233 K in each salty-ice sample, with CCMEE 171 showing an enhanced survivability, whereas there were no survivors at 203 K. The survival limit at low temperature was further extended when both strains were exposed to 193 K as air-dried cells. The results suggest that vitrification might be a strategy for microbial life forms to survive in potentially habitable icy moons, for example in Europa's icy crust. By entering a dried, frozen state, they could be transported from niches, which became non-habitable to new habitable ones, and possibly return to metabolic activity.
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Affiliation(s)
- Barbara Cosciotti
- Department of Mathematics and Physics, University of Rome Tre, 00154 Rome, Italy; (B.C.); (A.C.); (E.M.); (S.E.L.); (F.D.P.); (E.P.)
| | - Amedeo Balbi
- Department of Physics, University of Rome Tor Vergata, 00133 Rome, Italy;
| | - Alessandra Ceccarelli
- Department of Mathematics and Physics, University of Rome Tre, 00154 Rome, Italy; (B.C.); (A.C.); (E.M.); (S.E.L.); (F.D.P.); (E.P.)
| | - Claudia Fagliarone
- Department of Biology, University of Rome Tor Vergata, 00133 Rome, Italy;
| | - Elisabetta Mattei
- Department of Mathematics and Physics, University of Rome Tre, 00154 Rome, Italy; (B.C.); (A.C.); (E.M.); (S.E.L.); (F.D.P.); (E.P.)
| | - Sebastian Emanuel Lauro
- Department of Mathematics and Physics, University of Rome Tre, 00154 Rome, Italy; (B.C.); (A.C.); (E.M.); (S.E.L.); (F.D.P.); (E.P.)
| | - Federico Di Paolo
- Department of Mathematics and Physics, University of Rome Tre, 00154 Rome, Italy; (B.C.); (A.C.); (E.M.); (S.E.L.); (F.D.P.); (E.P.)
| | - Elena Pettinelli
- Department of Mathematics and Physics, University of Rome Tre, 00154 Rome, Italy; (B.C.); (A.C.); (E.M.); (S.E.L.); (F.D.P.); (E.P.)
| | - Daniela Billi
- Department of Biology, University of Rome Tor Vergata, 00133 Rome, Italy;
- Correspondence:
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15
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Grinberg M, Orevi T, Steinberg S, Kashtan N. Bacterial survival in microscopic surface wetness. eLife 2019; 8:e48508. [PMID: 31610846 PMCID: PMC6824842 DOI: 10.7554/elife.48508] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 09/20/2019] [Indexed: 01/06/2023] Open
Abstract
Plant leaves constitute a huge microbial habitat of global importance. How microorganisms survive the dry daytime on leaves and avoid desiccation is not well understood. There is evidence that microscopic surface wetness in the form of thin films and micrometer-sized droplets, invisible to the naked eye, persists on leaves during daytime due to deliquescence - the absorption of water until dissolution - of hygroscopic aerosols. Here, we study how such microscopic wetness affects cell survival. We show that, on surfaces drying under moderate humidity, stable microdroplets form around bacterial aggregates due to capillary pinning and deliquescence. Notably, droplet-size increases with aggregate-size, and cell survival is higher the larger the droplet. This phenomenon was observed for 13 bacterial species, two of which - Pseudomonas fluorescens and P. putida - were studied in depth. Microdroplet formation around aggregates is likely key to bacterial survival in a variety of unsaturated microbial habitats, including leaf surfaces.
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Affiliation(s)
- Maor Grinberg
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food, and EnvironmentHebrew UniversityRehovotIsrael
| | - Tomer Orevi
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food, and EnvironmentHebrew UniversityRehovotIsrael
| | - Shifra Steinberg
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food, and EnvironmentHebrew UniversityRehovotIsrael
| | - Nadav Kashtan
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food, and EnvironmentHebrew UniversityRehovotIsrael
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