1
|
Li Y, Collins D, Grintzalis K. A simple approach for the detection of Escherichia coli as a model bacterium on Martian soil simulants: A proof of concept study. J Microbiol Methods 2023; 210:106751. [PMID: 37271376 DOI: 10.1016/j.mimet.2023.106751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 05/25/2023] [Accepted: 05/27/2023] [Indexed: 06/06/2023]
Abstract
The possibility of microbial life beyond Earth presents a fundamental question in astrobiology. Given the likelihood that any extra-terrestrial life will be microbial in nature, the development of sensitive and specific confirmatory tests is crucial for the identification of potential habitats for life. Here, we describe a novel methodology for the detection of microorganisms in Martian soil simulants through spiking and recovery experiments. Our approach employs miniaturised techniques that enable the rapid and sensitive assessment of microbial presence in soil samples. The results of our study suggest that this methodology could be a valuable tool for the identification of potential habitats for microbial life on Mars and other extraterrestrial bodies.
Collapse
Affiliation(s)
- Yongda Li
- School of Biotechnology, Dublin City University, Ireland
| | - David Collins
- School of Biotechnology, Dublin City University, Ireland
| | | |
Collapse
|
2
|
Carr CE. Resolving the History of Life on Earth by Seeking Life As We Know It on Mars. ASTROBIOLOGY 2022; 22:880-888. [PMID: 35467949 PMCID: PMC9298492 DOI: 10.1089/ast.2021.0043] [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: 05/08/2023]
Abstract
An origin of Earth life on Mars would resolve significant inconsistencies between the inferred history of life and Earth's geologic history. Life as we know it utilizes amino acids, nucleic acids, and lipids for the metabolic, informational, and compartment-forming subsystems of a cell. Such building blocks may have formed simultaneously from cyanosulfidic chemical precursors in a planetary surface scenario involving ultraviolet light, wet-dry cycling, and volcanism. On the inferred water world of early Earth, such an origin would have been limited to volcanic island hotspots. A cyanosulfidic origin of life could have taken place on Mars via photoredox chemistry, facilitated by orders-of-magnitude more sub-aerial crust than early Earth, and an earlier transition to oxidative conditions that could have been involved in final fixation of the genetic code. Meteoritic bombardment may have generated transient habitable environments and ejected and transferred life to Earth. Ongoing and future missions to Mars offer an unprecedented opportunity to confirm or refute evidence consistent with a cyanosulfidic origin of life on Mars, search for evidence of ancient life, and constrain the evolution of Mars' oxidation state over time. We should seek to prove or refute a martian origin for life on Earth alongside other possibilities.
Collapse
Affiliation(s)
- Christopher E. Carr
- Daniel Guggenheim School of Aerospace Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- Address correspondence to: Christopher E. Carr, ESM Building, Room G10, 620 Cherry St NW, Atlanta, GA 30332, USA
| |
Collapse
|
3
|
Pacelli C, Cassaro A, Aureli L, Moeller R, Fujimori A, Onofri S. The Responses of the Black Fungus Cryomyces Antarcticus to High Doses of Accelerated Helium Ions Radiation within Martian Regolith Simulants and Their Relevance for Mars. Life (Basel) 2020; 10:E130. [PMID: 32752063 PMCID: PMC7459982 DOI: 10.3390/life10080130] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 07/21/2020] [Accepted: 07/28/2020] [Indexed: 12/22/2022] Open
Abstract
One of the primary current astrobiological goals is to understand the limits of microbial resistance to extraterrestrial conditions. Much attention is paid to ionizing radiation, since it can prevent the preservation and spread of life outside the Earth. The aim of this research was to study the impact of accelerated He ions (150 MeV/n, up to 1 kGy) as a component of the galactic cosmic rays on the black fungus C. antarcticus when mixed with Antarctic sandstones-the substratum of its natural habitat-and two Martian regolith simulants, which mimics two different evolutionary stages of Mars. The high dose of 1 kGy was used to assess the effect of dose accumulation in dormant cells within minerals, under long-term irradiation estimated on a geological time scale. The data obtained suggests that viable Earth-like microorganisms can be preserved in the dormant state in the near-surface scenario for approximately 322,000 and 110,000 Earth years within Martian regolith that mimic early and present Mars environmental conditions, respectively. In addition, the results of the study indicate the possibility of maintaining traces within regolith, as demonstrated by the identification of melanin pigments through UltraViolet-visible (UV-vis) spectrophotometric approach.
Collapse
Affiliation(s)
- Claudia Pacelli
- Italian Space Agency, Via del Politecnico snc, 00133 Rome, Italy;
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell’Università snc, 01100 Viterbo, Italy; (L.A.); (S.O.)
| | - Alessia Cassaro
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell’Università snc, 01100 Viterbo, Italy; (L.A.); (S.O.)
| | - Lorenzo Aureli
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell’Università snc, 01100 Viterbo, Italy; (L.A.); (S.O.)
| | - Ralf Moeller
- German Aerospace Center, Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, DLR, Linder Höhe, D-51147 Köln, Germany; or
- Department of Natural Science, University of Applied Sciences Bonn-Rhein-Sieg (BRSU), von-Liebig-Straße 20, D-53359 Rheinbach, Germany
| | - Akira Fujimori
- Molecular and Cellular Radiation Biology Group, Department of Basic Medical Sciences for Radiation Damages, NIRS/QST, Chiba 263-8555, Japan;
| | - Silvano Onofri
- Department of Ecological and Biological Sciences, University of Tuscia, Largo dell’Università snc, 01100 Viterbo, Italy; (L.A.); (S.O.)
| |
Collapse
|
4
|
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
|
5
|
Mojarro A, Hachey J, Bailey R, Brown M, Doebler R, Ruvkun G, Zuber MT, Carr CE. Nucleic Acid Extraction and Sequencing from Low-Biomass Synthetic Mars Analog Soils for In Situ Life Detection. ASTROBIOLOGY 2019; 19:1139-1152. [PMID: 31204862 PMCID: PMC6708270 DOI: 10.1089/ast.2018.1929] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Recent studies regarding the origins of life and Mars-Earth meteorite transfer simulations suggest that biological informational polymers, such as nucleic acids (DNA and RNA), have the potential to provide unambiguous evidence of life on Mars. To this end, we are developing a metagenomics-based life-detection instrument which integrates nucleic acid extraction and nanopore sequencing: the Search for Extra-Terrestrial Genomes (SETG). Our goal is to isolate and sequence nucleic acids from extant or preserved life on Mars in order to determine if a particular genetic sequence (1) is distantly related to life on Earth, indicating a shared ancestry due to lithological exchange, or (2) is unrelated to life on Earth, suggesting convergent origins of life on Mars. In this study, we validate prior work on nucleic acid extraction from cells deposited in Mars analog soils down to microbial concentrations (i.e., 104 cells in 50 mg of soil) observed in the driest and coldest regions on Earth. In addition, we report low-input nanopore sequencing results from 2 pg of purified Bacillus subtilis spore DNA simulating ideal extraction yields equivalent to 1 ppb life-detection sensitivity. We achieve this by employing carrier sequencing, a method of sequencing sub-nanogram DNA in the background of a genomic carrier. After filtering of carrier, low-quality, and low-complexity reads we detected 5 B. subtilis reads, 18 contamination reads (including Homo sapiens), and 6 high-quality noise reads believed to be sequencing artifacts.
Collapse
Affiliation(s)
- Angel Mojarro
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Address correspondence to: Angel Mojarro, Massachusetts Institute of Technology, 77 Massachusetts Ave, Room E25-647, Cambridge, MA 02139
| | | | - Ryan Bailey
- Claremont Biosolutions, LLC, Upland, California
| | - Mark Brown
- Claremont Biosolutions, LLC, Upland, California
| | | | - Gary Ruvkun
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts
| | - Maria T. Zuber
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Christopher E. Carr
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts
| |
Collapse
|
6
|
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.
Collapse
|
7
|
Merino N, Aronson HS, Bojanova DP, Feyhl-Buska J, Wong ML, Zhang S, Giovannelli D. Corrigendum: Living at the Extremes: Extremophiles and the Limits of Life in a Planetary Context. Front Microbiol 2019; 10:1785. [PMID: 31456760 PMCID: PMC6700686 DOI: 10.3389/fmicb.2019.01785] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 07/18/2019] [Indexed: 11/27/2022] Open
Affiliation(s)
- Nancy Merino
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States.,Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan.,Biosciences and Biotechnology Division, Physical and Life Sciences Directorate, Lawrence Livermore National Lab, Livermore, CA, United States
| | - Heidi S Aronson
- Department of Biology, University of Southern California, Los Angeles, CA, United States
| | - Diana P Bojanova
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States
| | - Jayme Feyhl-Buska
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States
| | - Michael L Wong
- Department of Astronomy - Astrobiology Program, University of Washington, Seattle, WA, United States.,NASA Astrobiology Institute's Virtual Planetary Laboratory, University of Washington, Seattle, WA, United States
| | - Shu Zhang
- Section of Infection and Immunity, Herman Ostrow School of Dentistry of USC, University of Southern California, Los Angeles, CA, United States
| | - Donato Giovannelli
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan.,Department of Biology, University of Naples "Federico II", Naples, Italy.,Department of Marine and Coastal Science, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States.,Institute for Biological Resources and Marine Biotechnology, National Research Council of Italy, Ancona, Italy
| |
Collapse
|
8
|
Merino N, Aronson HS, Bojanova DP, Feyhl-Buska J, Wong ML, Zhang S, Giovannelli D. Living at the Extremes: Extremophiles and the Limits of Life in a Planetary Context. Front Microbiol 2019; 10:780. [PMID: 31037068 PMCID: PMC6476344 DOI: 10.3389/fmicb.2019.00780] [Citation(s) in RCA: 215] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 03/27/2019] [Indexed: 01/21/2023] Open
Abstract
Prokaryotic life has dominated most of the evolutionary history of our planet, evolving to occupy virtually all available environmental niches. Extremophiles, especially those thriving under multiple extremes, represent a key area of research for multiple disciplines, spanning from the study of adaptations to harsh conditions, to the biogeochemical cycling of elements. Extremophile research also has implications for origin of life studies and the search for life on other planetary and celestial bodies. In this article, we will review the current state of knowledge for the biospace in which life operates on Earth and will discuss it in a planetary context, highlighting knowledge gaps and areas of opportunity.
Collapse
Affiliation(s)
- Nancy Merino
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States.,Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan.,Biosciences and Biotechnology Division, Physical and Life Sciences Directorate, Lawrence Livermore National Lab, Livermore, CA, United States
| | - Heidi S Aronson
- Department of Biology, University of Southern California, Los Angeles, CA, United States
| | - Diana P Bojanova
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States
| | - Jayme Feyhl-Buska
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States
| | - Michael L Wong
- Department of Astronomy - Astrobiology Program, University of Washington, Seattle, WA, United States.,NASA Astrobiology Institute's Virtual Planetary Laboratory, University of Washington, Seattle, WA, United States
| | - Shu Zhang
- Section of Infection and Immunity, Herman Ostrow School of Dentistry of USC, University of Southern California, Los Angeles, CA, United States
| | - Donato Giovannelli
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan.,Department of Biology, University of Naples "Federico II", Naples, Italy.,Department of Marine and Coastal Science, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States.,Institute for Biological Resources and Marine Biotechnology, National Research Council of Italy, Ancona, Italy
| |
Collapse
|
9
|
Survivability of Soil and Permafrost Microbial Communities after Irradiation with Accelerated Electrons under Simulated Martian and Open Space Conditions. GEOSCIENCES 2018. [DOI: 10.3390/geosciences8080298] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
One of the prior current astrobiological tasks is revealing the limits of microbial resistance to extraterrestrial conditions. Much attention is paid to ionizing radiation, since it can prevent the preservation and spread of life outside the Earth. The aim of this research was to study the impact of accelerated electrons (~1 MeV) as component of space radiation on microbial communities in their natural habitat—the arid soil and ancient permafrost, and also on the pure bacterial cultures that were isolated from these ecotopes. The irradiation was carried out at low pressure (~0.01 Torr) and low temperature (−130 °C) to simulate the conditions of Mars or outer space. High doses of 10 kGy and 100 kGy were used to assess the effect of dose accumulation in inactive and hypometabolic cells, depending on environmental conditions under long-term irradiation estimated on a geological time scale. It was shown that irradiation with accelerated electrons in the applied doses did not sterilize native samples from Earth extreme habitats. The data obtained suggests that viable Earth-like microorganisms can be preserved in the anabiotic state for at least 1.3 and 20 million years in the regolith of modern Mars in the shallow subsurface layer and at a 5 m depth, respectively. In addition, the results of the study indicate the possibility of maintaining terrestrial like life in the ice of Europa at a 10 cm depth for at least ~170 years or for at least 400 thousand years in open space within meteorites. It is established that bacteria in natural habitat has a much higher resistance to in situ irradiation with accelerated electrons when compared to their stability in pure isolated cultures. Thanks to the protective properties of the heterophase environment and the interaction between microbial populations even radiosensitive microorganisms as members of the native microbial communities are able to withstand very high doses of ionizing radiation.
Collapse
|
10
|
Cheptsov VS, Vorobyova EA, Osipov GA, Manucharova NA, Polyanskaya LM, Gorlenko MV, Pavlov AK, Rosanova MS, Lomasov VN. Microbial activity in Martian analog soils after ionizing radiation: implications for the preservation of subsurface life on Mars. AIMS Microbiol 2018; 4:541-562. [PMID: 31294232 PMCID: PMC6604939 DOI: 10.3934/microbiol.2018.3.541] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 07/04/2018] [Indexed: 11/18/2022] Open
Abstract
At present, the surface of Mars is affected by a set of factors that can prevent the survival of Earth-like life. However, the modern concept of the evolution of the planet assumes the existence more favorable for life climate in the past. If in the past on Mars had formed a biosphere, similar to the one that originated in the early Earth, it is supposed that it is preserved till now in anabiotic state in the bowels of the planet, like microbial communities inhabiting the ancient permafrost of Arctic and Antarctic. In the conditions of modern Martian regolith, this relic life seems to be deprived of the possibility of damage reparation (or these processes occur on a geological time scale), and ionizing radiation should be considered the main factor inhibiting such anabiotic life. In the present study, we studied soil samples, selected in two different extreme habitats of the Earth: ancient permafrost from the Dry Valleys of Antarctica and Xerosol soil from the mountain desert in Morocco, gamma-irradiated with 40 kGy dose at low pressure (1 Torr) and low temperature (-50 °C). Microbial communities inhabiting these samples showed in situ high resistance to the applied effects, retained high number of viable cells, metabolic activity, and high biodiversity. Based on the results, it is assumed that the putative biosphere could be preserved in the dormant state for at least 500 thousand years and 8 million years in the surface layer of Mars regolith and at 5 m depth, respectively, at the current level of ionizing radiation intensity.
Collapse
Affiliation(s)
- Vladimir S Cheptsov
- Soil Science Faculty, Lomonosov Moscow State University, Moscow, Russia.,Space Research Institute, Russian Academy of Sciences, Moscow, Russia
| | - Elena A Vorobyova
- Soil Science Faculty, Lomonosov Moscow State University, Moscow, Russia.,Space Research Institute, Russian Academy of Sciences, Moscow, Russia
| | - George A Osipov
- International Analytical Center, Interlab, N.D.Zelinsky Institute of Organic Chemistry, Moscow, Russia
| | | | | | | | - Anatoli K Pavlov
- Ioffe Physical-Technical Institute, Russian Academy of Sciences, St. Petersburg, Russia
| | - Marina S Rosanova
- Soil Science Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Vladimir N Lomasov
- Peter the Great St. Petersburg State Polytechnic University, St. Petersburg, Russia
| |
Collapse
|
11
|
Cabrol NA. The Coevolution of Life and Environment on Mars: An Ecosystem Perspective on the Robotic Exploration of Biosignatures. ASTROBIOLOGY 2018; 18:1-27. [PMID: 29252008 PMCID: PMC5779243 DOI: 10.1089/ast.2017.1756] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/27/2017] [Indexed: 05/09/2023]
Abstract
Earth's biological and environmental evolution are intertwined and inseparable. This coevolution has become a fundamental concept in astrobiology and is key to the search for life beyond our planet. In the case of Mars, whether a coevolution took place is unknown, but analyzing the factors at play shows the uniqueness of each planetary experiment regardless of similarities. Early Earth and early Mars shared traits. However, biological processes on Mars, if any, would have had to proceed within the distinctive context of an irreversible atmospheric collapse, greater climate variability, and specific planetary characteristics. In that, Mars is an important test bed for comparing the effects of a unique set of spatiotemporal changes on an Earth-like, yet different, planet. Many questions remain unanswered about Mars' early environment. Nevertheless, existing data sets provide a foundation for an intellectual framework where notional coevolution models can be explored. In this framework, the focus is shifted from planetary-scale habitability to the prospect of habitats, microbial ecotones, pathways to biological dispersal, biomass repositories, and their meaning for exploration. Critically, as we search for biosignatures, this focus demonstrates the importance of starting to think of early Mars as a biosphere and vigorously integrating an ecosystem approach to landing site selection and exploration. Key Words: Astrobiology-Biosignatures-Coevolution of Earth and life-Mars. Astrobiology 18, 1-27.
Collapse
|
12
|
Mickol RL, Kral TA. Low Pressure Tolerance by Methanogens in an Aqueous Environment: Implications for Subsurface Life on Mars. ORIGINS LIFE EVOL B 2017; 47:511-532. [PMID: 27663448 DOI: 10.1007/s11084-016-9519-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 09/05/2016] [Indexed: 11/26/2022]
Abstract
The low pressure at the surface of Mars (average: 6 mbar) is one potentially biocidal factor that any extant life on the planet would need to endure. Near subsurface life, while shielded from ultraviolet radiation, would also be exposed to this low pressure environment, as the atmospheric gas-phase pressure increases very gradually with depth. Few studies have focused on low pressure as inhibitory to the growth or survival of organisms. However, recent work has uncovered a potential constraint to bacterial growth below 25 mbar. The study reported here tested the survivability of four methanogen species (Methanothermobacter wolfeii, Methanosarcina barkeri, Methanobacterium formicicum, Methanococcus maripaludis) under low pressure conditions approaching average martian surface pressure (6 mbar - 143 mbar) in an aqueous environment. Each of the four species survived exposure of varying length (3 days - 21 days) at pressures down to 6 mbar. This research is an important stepping-stone to determining if methanogens can actively metabolize/grow under these low pressures. Additionally, the recently discovered recurring slope lineae suggest that liquid water columns may connect the surface to deeper levels in the subsurface. If that is the case, any organism being transported in the water column would encounter the changing pressures during the transport.
Collapse
Affiliation(s)
- R L Mickol
- Arkansas Center for Space and Planetary Sciences, University of Arkansas, Stone House North, 332 N. Arkansas Ave, Fayetteville, AR, 72701, USA.
| | - T A Kral
- Arkansas Center for Space and Planetary Sciences, University of Arkansas, Stone House North, 332 N. Arkansas Ave, Fayetteville, AR, 72701, USA
- Department of Biological Sciences, Science and Engineering 601, University of Arkansas, Fayetteville, AR, 72701, USA
| |
Collapse
|
13
|
Uckert K, Chanover NJ, Getty S, Voelz DG, Brinckerhoff WB, McMillan N, Xiao X, Boston PJ, Li X, McAdam A, Glenar DA, Chavez A. The Characterization of Biosignatures in Caves Using an Instrument Suite. ASTROBIOLOGY 2017; 17:1203-1218. [PMID: 29227156 DOI: 10.1089/ast.2016.1568] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The search for life and habitable environments on other Solar System bodies is a major motivator for planetary exploration. Due to the difficulty and significance of detecting extant or extinct extraterrestrial life in situ, several independent measurements from multiple instrument techniques will bolster the community's confidence in making any such claim. We demonstrate the detection of subsurface biosignatures using a suite of instrument techniques including IR reflectance spectroscopy, laser-induced breakdown spectroscopy, and scanning electron microscopy/energy dispersive X-ray spectroscopy. We focus our measurements on subterranean calcium carbonate field samples, whose biosignatures are analogous to those that might be expected on some high-interest astrobiology targets. In this work, we discuss the feasibility and advantages of using each of the aforementioned instrument techniques for the in situ search for biosignatures and present results on the autonomous characterization of biosignatures using multivariate statistical analysis techniques. Key Words: Biosignature suites-Caves-Mars-Life detection. Astrobiology 17, 1203-1218.
Collapse
Affiliation(s)
- Kyle Uckert
- 1 Department of Astronomy, New Mexico State University , Las Cruces, New Mexico
| | - Nancy J Chanover
- 1 Department of Astronomy, New Mexico State University , Las Cruces, New Mexico
| | | | - David G Voelz
- 3 Department of Electrical and Computer Engineering, New Mexico State University , Las Cruces, New Mexico
| | | | - Nancy McMillan
- 4 Department of Geological Sciences, New Mexico State University , Las Cruces, New Mexico
| | - Xifeng Xiao
- 3 Department of Electrical and Computer Engineering, New Mexico State University , Las Cruces, New Mexico
| | - Penelope J Boston
- 5 NASA Astrobiology Institute , NASA Ames Research Center, Moffett Field, California
| | - Xiang Li
- 6 University of Maryland , Baltimore County, Baltimore, Maryland
| | - Amy McAdam
- 2 NASA/Goddard Space Flight Center , Greenbelt, Maryland
| | - David A Glenar
- 6 University of Maryland , Baltimore County, Baltimore, Maryland
| | - Arriana Chavez
- 4 Department of Geological Sciences, New Mexico State University , Las Cruces, New Mexico
| |
Collapse
|
14
|
Chopra A, Lineweaver CH. The Case for a Gaian Bottleneck: The Biology of Habitability. ASTROBIOLOGY 2016; 16:7-22. [PMID: 26789354 DOI: 10.1089/ast.2015.1387] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The prerequisites and ingredients for life seem to be abundantly available in the Universe. However, the Universe does not seem to be teeming with life. The most common explanation for this is a low probability for the emergence of life (an emergence bottleneck), notionally due to the intricacies of the molecular recipe. Here, we present an alternative Gaian bottleneck explanation: If life emerges on a planet, it only rarely evolves quickly enough to regulate greenhouse gases and albedo, thereby maintaining surface temperatures compatible with liquid water and habitability. Such a Gaian bottleneck suggests that (i) extinction is the cosmic default for most life that has ever emerged on the surfaces of wet rocky planets in the Universe and (ii) rocky planets need to be inhabited to remain habitable. In the Gaian bottleneck model, the maintenance of planetary habitability is a property more associated with an unusually rapid evolution of biological regulation of surface volatiles than with the luminosity and distance to the host star.
Collapse
Affiliation(s)
- Aditya Chopra
- Planetary Science Institute, Research School of Earth Sciences, Research School of Astronomy and Astrophysics, The Australian National University , Canberra, Australia
| | - Charles H Lineweaver
- Planetary Science Institute, Research School of Earth Sciences, Research School of Astronomy and Astrophysics, The Australian National University , Canberra, Australia
| |
Collapse
|
15
|
Cockell CS, Bush T, Bryce C, Direito S, Fox-Powell M, Harrison JP, Lammer H, Landenmark H, Martin-Torres J, Nicholson N, Noack L, O'Malley-James J, Payler SJ, Rushby A, Samuels T, Schwendner P, Wadsworth J, Zorzano MP. Habitability: A Review. ASTROBIOLOGY 2016; 16:89-117. [PMID: 26741054 DOI: 10.1089/ast.2015.1295] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Habitability is a widely used word in the geoscience, planetary science, and astrobiology literature, but what does it mean? In this review on habitability, we define it as the ability of an environment to support the activity of at least one known organism. We adopt a binary definition of "habitability" and a "habitable environment." An environment either can or cannot sustain a given organism. However, environments such as entire planets might be capable of supporting more or less species diversity or biomass compared with that of Earth. A clarity in understanding habitability can be obtained by defining instantaneous habitability as the conditions at any given time in a given environment required to sustain the activity of at least one known organism, and continuous planetary habitability as the capacity of a planetary body to sustain habitable conditions on some areas of its surface or within its interior over geological timescales. We also distinguish between surface liquid water worlds (such as Earth) that can sustain liquid water on their surfaces and interior liquid water worlds, such as icy moons and terrestrial-type rocky planets with liquid water only in their interiors. This distinction is important since, while the former can potentially sustain habitable conditions for oxygenic photosynthesis that leads to the rise of atmospheric oxygen and potentially complex multicellularity and intelligence over geological timescales, the latter are unlikely to. Habitable environments do not need to contain life. Although the decoupling of habitability and the presence of life may be rare on Earth, it may be important for understanding the habitability of other planetary bodies.
Collapse
Affiliation(s)
- C S Cockell
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - T Bush
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - C Bryce
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - S Direito
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - M Fox-Powell
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - J P Harrison
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - H Lammer
- 2 Austrian Academy of Sciences, Space Research Institute , Graz, Austria
| | - H Landenmark
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - J Martin-Torres
- 3 Division of Space Technology, Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology , Kiruna, Sweden; and Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR), Armilla, Granada, Spain
| | - N Nicholson
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - L Noack
- 4 Department of Reference Systems and Planetology, Royal Observatory of Belgium , Brussels, Belgium
| | - J O'Malley-James
- 5 School of Physics and Astronomy, University of St Andrews , St Andrews, UK; now at the Carl Sagan Institute, Cornell University, Ithaca, NY, USA
| | - S J Payler
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - A Rushby
- 6 Centre for Ocean and Atmospheric Science (COAS), School of Environmental Sciences, University of East Anglia , Norwich, UK
| | - T Samuels
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - P Schwendner
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - J Wadsworth
- 1 UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh , Edinburgh, UK
| | - M P Zorzano
- 3 Division of Space Technology, Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology , Kiruna, Sweden; and Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR), Armilla, Granada, Spain
- 7 Centro de Astrobiología (CSIC-INTA) , Torrejón de Ardoz, Madrid, Spain
| |
Collapse
|
16
|
Schirmack J, Alawi M, Wagner D. Influence of Martian regolith analogs on the activity and growth of methanogenic archaea, with special regard to long-term desiccation. Front Microbiol 2015; 6:210. [PMID: 25852668 PMCID: PMC4367439 DOI: 10.3389/fmicb.2015.00210] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 03/02/2015] [Indexed: 12/05/2022] Open
Abstract
Methanogenic archaea have been studied as model organisms for possible life on Mars for several reasons: they can grow lithoautotrophically by using hydrogen and carbon dioxide as energy and carbon sources, respectively; they are anaerobes; and they evolved at a time when conditions on early Earth are believed to have looked similar to those of early Mars. As Mars is currently dry and cold and as water might be available only at certain time intervals, any organism living on this planet would need to cope with desiccation. On Earth there are several regions with low water availability as well, e.g., permafrost environments, desert soils, and salt pans. Here, we present the results of a set of experiments investigating the influence of different Martian regolith analogs (MRAs) on the metabolic activity and growth of three methanogenic strains exposed to culture conditions as well as long-term desiccation. In most cases, concentrations below 1 wt% of regolith in the media resulted in an increase of methane production rates, whereas higher concentrations decreased the rates, thus prolonging the lag phase. Further experiments showed that methanogenic archaea are capable of producing methane when incubated on a water-saturated sedimentary matrix of regolith lacking nutrients. Survival of methanogens under these conditions was analyzed with a 400 day desiccation experiment in the presence of regolith analogs. All tested strains of methanogens survived the desiccation period as it was determined through reincubation on fresh medium and via qPCR following propidium monoazide treatment to identify viable cells. The survival of long-term desiccation and the ability of active metabolism on water-saturated MRAs strengthens the possibility of methanogenic archaea or physiologically similar organisms to exist in environmental niches on Mars. The best results were achieved in presence of a phyllosilicate, which provides insights of possible positive effects in habitats on Earth as well.
Collapse
Affiliation(s)
- Janosch Schirmack
- Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research - Research Unit Potsdam, Potsdam Germany
| | - Mashal Alawi
- GFZ German Research Centre for Geosciences, Section 4.5 Geomicrobiology, Potsdam Germany
| | - Dirk Wagner
- GFZ German Research Centre for Geosciences, Section 4.5 Geomicrobiology, Potsdam Germany
| |
Collapse
|
17
|
Rummel JD, Beaty DW, Jones MA, Bakermans C, Barlow NG, Boston PJ, Chevrier VF, Clark BC, de Vera JPP, Gough RV, Hallsworth JE, Head JW, Hipkin VJ, Kieft TL, McEwen AS, Mellon MT, Mikucki JA, Nicholson WL, Omelon CR, Peterson R, Roden EE, Sherwood Lollar B, Tanaka KL, Viola D, Wray JJ. A new analysis of Mars "Special Regions": findings of the second MEPAG Special Regions Science Analysis Group (SR-SAG2). ASTROBIOLOGY 2014; 14:887-968. [PMID: 25401393 DOI: 10.1089/ast.2014.1227] [Citation(s) in RCA: 148] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
A committee of the Mars Exploration Program Analysis Group (MEPAG) has reviewed and updated the description of Special Regions on Mars as places where terrestrial organisms might replicate (per the COSPAR Planetary Protection Policy). This review and update was conducted by an international team (SR-SAG2) drawn from both the biological science and Mars exploration communities, focused on understanding when and where Special Regions could occur. The study applied recently available data about martian environments and about terrestrial organisms, building on a previous analysis of Mars Special Regions (2006) undertaken by a similar team. Since then, a new body of highly relevant information has been generated from the Mars Reconnaissance Orbiter (launched in 2005) and Phoenix (2007) and data from Mars Express and the twin Mars Exploration Rovers (all 2003). Results have also been gleaned from the Mars Science Laboratory (launched in 2011). In addition to Mars data, there is a considerable body of new data regarding the known environmental limits to life on Earth-including the potential for terrestrial microbial life to survive and replicate under martian environmental conditions. The SR-SAG2 analysis has included an examination of new Mars models relevant to natural environmental variation in water activity and temperature; a review and reconsideration of the current parameters used to define Special Regions; and updated maps and descriptions of the martian environments recommended for treatment as "Uncertain" or "Special" as natural features or those potentially formed by the influence of future landed spacecraft. Significant changes in our knowledge of the capabilities of terrestrial organisms and the existence of possibly habitable martian environments have led to a new appreciation of where Mars Special Regions may be identified and protected. The SR-SAG also considered the impact of Special Regions on potential future human missions to Mars, both as locations of potential resources and as places that should not be inadvertently contaminated by human activity.
Collapse
Affiliation(s)
- John D Rummel
- 1 Department of Biology, East Carolina University , Greenville, North Carolina, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Abbey W, Salas E, Bhartia R, Beegle LW. The Mojave vadose zone: a subsurface biosphere analogue for Mars. ASTROBIOLOGY 2013; 13:637-646. [PMID: 23848498 DOI: 10.1089/ast.2012.0948] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
If life ever evolved on the surface of Mars, it is unlikely that it would still survive there today, but as Mars evolved from a wet planet to an arid one, the subsurface environment may have presented a refuge from increasingly hostile surface conditions. Since the last glacial maximum, the Mojave Desert has experienced a similar shift from a wet to a dry environment, giving us the opportunity to study here on Earth how subsurface ecosystems in an arid environment adapt to increasingly barren surface conditions. In this paper, we advocate studying the vadose zone ecosystem of the Mojave Desert as an analogue for possible subsurface biospheres on Mars. We also describe several examples of Mars-like terrain found in the Mojave region and discuss ecological insights that might be gained by a thorough examination of the vadose zone in these specific terrains. Examples described include distributary fans (deltas, alluvial fans, etc.), paleosols overlain by basaltic lava flows, and evaporite deposits.
Collapse
Affiliation(s)
- William Abbey
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | | | | | | |
Collapse
|
19
|
The limits for life under multiple extremes. Trends Microbiol 2013; 21:204-12. [DOI: 10.1016/j.tim.2013.01.006] [Citation(s) in RCA: 168] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 01/28/2013] [Accepted: 01/31/2013] [Indexed: 12/19/2022]
|
20
|
Growth of Carnobacterium spp. from permafrost under low pressure, temperature, and anoxic atmosphere has implications for Earth microbes on Mars. Proc Natl Acad Sci U S A 2012; 110:666-71. [PMID: 23267097 DOI: 10.1073/pnas.1209793110] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The ability of terrestrial microorganisms to grow in the near-surface environment of Mars is of importance to the search for life and protection of that planet from forward contamination by human and robotic exploration. Because most water on present-day Mars is frozen in the regolith, permafrosts are considered to be terrestrial analogs of the martian subsurface environment. Six bacterial isolates were obtained from a permafrost borehole in northeastern Siberia capable of growth under conditions of low temperature (0 °C), low pressure (7 mbar), and a CO(2)-enriched anoxic atmosphere. By 16S ribosomal DNA analysis, all six permafrost isolates were identified as species of the genus Carnobacterium, most closely related to C. inhibens (five isolates) and C. viridans (one isolate). Quantitative growth assays demonstrated that the six permafrost isolates, as well as nine type species of Carnobacterium (C. alterfunditum, C. divergens, C. funditum, C. gallinarum, C. inhibens, C. maltaromaticum, C. mobile, C. pleistocenium, and C. viridans) were all capable of growth under cold, low-pressure, anoxic conditions, thus extending the low-pressure extreme at which life can function.
Collapse
|