1
|
Ramkissoon NK, Macey MC, Kucukkilic-Stephens E, Barton T, Steele A, Johnson DN, Stephens BP, Schwenzer SP, Pearson VK, Olsson-Francis K. Experimental Identification of Potential Martian Biosignatures in Open and Closed Systems. ASTROBIOLOGY 2024; 24:538-558. [PMID: 38648554 DOI: 10.1089/ast.2023.0013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
NASA's Perseverance and ESA's Rosalind Franklin rovers have the scientific goal of searching for evidence of ancient life on Mars. Geochemical biosignatures that form because of microbe-mineral interactions could play a key role in achieving this, as they can be preserved for millions of years on Earth, and the same could be true for Mars. Previous laboratory experiments have explored the formation of biosignatures under closed systems, but these do not represent the open systems that are found in natural martian environments, such as channels and lakes. In this study, we have conducted environmental simulation experiments using a global regolith simulant (OUCM-1), a thermochemically modelled groundwater, and an anaerobic microbial community to explore the formation of geochemical biosignatures within plausible open and closed systems on Mars. This initial investigation showed differences in the diversity of the microbial community developed after 28 days. In an open-system simulation (flow-through experiment), the acetogenic Acetobacterium (49% relative abundance) and the sulfate reducer Desulfosporomusa (43% relative abundance) were the dominant genera. Whereas in the batch experiment, the sulfate reducers Desulfovibrio, Desulfomicrobium, and Desulfuromonas (95% relative abundance in total) were dominant. We also found evidence of enhanced mineral dissolution within the flow-through experiment, but there was little evidence of secondary deposits in the presence of biota. In contrast, SiO2 and Fe deposits formed within the batch experiment with biota but not under abiotic conditions. The results from these initial experiments indicate that different geochemical biosignatures can be generated between open and closed systems, and therefore, biosignature formation in open systems warrants further investigation.
Collapse
Affiliation(s)
| | - Michael C Macey
- AstrobiologyOU, STEM Faculty, The Open University, Milton Keynes, UK
| | | | - Timothy Barton
- AstrobiologyOU, STEM Faculty, The Open University, Milton Keynes, UK
| | - Andrew Steele
- Earth and Planetary Laboratory, Carnegie Institution of Washington, Washington, DC, USA
| | - David N Johnson
- AstrobiologyOU, STEM Faculty, The Open University, Milton Keynes, UK
| | - Ben P Stephens
- AstrobiologyOU, STEM Faculty, The Open University, Milton Keynes, UK
| | | | | | | |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Oliver JAW, Kelbrick M, Ramkissoon NK, Dugdale A, Stephens BP, Kucukkilic-Stephens E, Fox-Powell MG, Schwenzer SP, Antunes A, Macey MC. Sulfur Cycling as a Viable Metabolism under Simulated Noachian/Hesperian Chemistries. Life (Basel) 2022; 12:life12040523. [PMID: 35455014 PMCID: PMC9024814 DOI: 10.3390/life12040523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/24/2022] [Accepted: 03/30/2022] [Indexed: 12/17/2022] Open
Abstract
Water present on the surface of early Mars (>3.0 Ga) may have been habitable. Characterising analogue environments and investigating the aspects of their microbiome best suited for growth under simulated martian chemical conditions is key to understanding potential habitability. Experiments were conducted to investigate the viability of microbes from a Mars analogue environment, Colour Peak Springs (Axel Heiberg Island, Canadian High Arctic), under simulated martian chemistries. The fluid was designed to emulate waters thought to be typical of the late Noachian, in combination with regolith simulant material based on two distinct martian geologies. These experiments were performed with a microbial community from Colour Peak Springs sediment. The impact on the microbes was assessed by cell counting and 16S rRNA gene amplicon sequencing. Changes in fluid chemistries were tested using ICP-OES. Both chemistries were shown to be habitable, with growth in both chemistries. Microbial communities exhibited distinct growth dynamics and taxonomic composition, comprised of sulfur-cycling bacteria, represented by either sulfate-reducing or sulfur-oxidising bacteria, and additional heterotrophic halophiles. Our data support the identification of Colour Peak Springs as an analogue for former martian environments, with a specific subsection of the biota able to survive under more accurate proxies for martian chemistries.
Collapse
Affiliation(s)
- James A. W. Oliver
- Biology Department, Edge Hill University, Ormskirk L39 4QP, UK; (J.A.W.O.); (M.K.)
| | - Matthew Kelbrick
- Biology Department, Edge Hill University, Ormskirk L39 4QP, UK; (J.A.W.O.); (M.K.)
- Department of Evolution, Ecology and Behaviour, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L69 3GJ, UK
| | - Nisha K. Ramkissoon
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (M.G.F.-P.); (S.P.S.)
| | - Amy Dugdale
- AstrobiologyOU, School of Physical Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK;
- Biology Department, Maynooth University, Maynooth, W23 F2H6 Kildare, Ireland
| | - Ben P. Stephens
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (M.G.F.-P.); (S.P.S.)
| | - Ezgi Kucukkilic-Stephens
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (M.G.F.-P.); (S.P.S.)
| | - Mark G. Fox-Powell
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (M.G.F.-P.); (S.P.S.)
- School of Earth & Environmental Sciences, University of St Andrews, Fife KY16 9AJ, UK
| | - Susanne P. Schwenzer
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (M.G.F.-P.); (S.P.S.)
| | - André Antunes
- State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology (MUST), Macau, China;
- China National Space Administration (CNSA), Macau Center for Space Exploration and Science, Macau, China
| | - Michael C. Macey
- AstrobiologyOU, School of Environment, Earth and Ecosystem Sciences, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes MK7 6AA, UK; (N.K.R.); (B.P.S.); (E.K.-S.); (M.G.F.-P.); (S.P.S.)
- Correspondence:
| |
Collapse
|
4
|
Thermodynamic Constraints on Smectite and Iron Oxide Formation at Gale Crater, Mars: Insights into Potential Free Energy from Aerobic Fe Oxidation in Lake Water–Groundwater Mixing Zone. MINERALS 2021. [DOI: 10.3390/min11040341] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The presence of saponite and iron oxides in Sheepbed mudstone of Yellowknife Bay at Gale crater on Mars is considered as evidence of a habitable fluvio-lacustrine environment for chemolithoautotrophy. However, the energetic availability for metabolic reactions is poorly constrained. Herein, we propose the possible mixing of surface water and groundwater that (i) explains the formation of magnetite and hematite detected in Sheepbed mudstone and (ii) may work as a potential habitable zone for aerobic Fe2+-oxidizing microbes. Our thermodynamic modeling of water–rock reactions revealed that the formation of abundant saponite in Sheepbed mudstone may occur under various conditions of water-to-rock mass ratios, temperatures (5–200 °C), and initial fluid compositions. In contrast, the formation of iron oxides in the mudstone can be explained only by the mixing of Fe2+-rich groundwater and more oxidized surface waters, where the Fe2+-rich groundwater can be generated by the low-temperature water–rock reactions with a CO2-bearing initial fluid. The calculated bioavailable energy of aerobic Fe2+ oxidation in the fluid-mixing zone on Mars is similar to that estimated for a fluid-mixing zone on Earth actually inhabited by aerobic Fe2+-oxidizing microbes. The findings will contribute to a better understanding of potential habitability on Mars.
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Draft Genome Sequence of Clostridium sp. Strain E02, Isolated from an Estuarine Environment. Microbiol Resour Announc 2019; 8:MRA01579-18. [PMID: 30643903 PMCID: PMC6328676 DOI: 10.1128/mra.01579-18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 12/11/2018] [Indexed: 11/20/2022] Open
Abstract
Here, we report the draft genome sequence of a strain of Clostridium isolated from sediment collected from an estuarine environment. The strain was isolated using a minimal medium designed to select for chemoautotrophic microorganisms. The strain may represent a novel species within the genus Clostridium, and this genome sequence enables further investigation into the genetic and metabolic diversity of this organism.
Collapse
|