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Borges SR, Jones GG, Robinson TD. Detectability of Surface Biosignatures for Directly Imaged Rocky Exoplanets. ASTROBIOLOGY 2024; 24:283-299. [PMID: 38377582 DOI: 10.1089/ast.2023.0099] [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: 02/22/2024]
Abstract
Modeling the detection of life has never been more opportune. With next-generation space telescopes, such as the currently developing Habitable Worlds Observatory (HWO) concept, we will begin to characterize rocky exoplanets potentially similar to Earth. However, few realistic planetary spectra containing surface biosignatures have been paired with direct imaging telescope instrument models. Therefore, we use a HWO instrument noise model to assess the detection of surface biosignatures affiliated with oxygenic, anoxygenic, and nonphotosynthetic extremophiles. We pair the HWO telescope model to a one-dimensional radiative transfer model to estimate the required exposure times necessary for detecting each biosignature on planets with global microbial coverage and varying atmospheric water vapor concentrations. For modeled planets with 0-50% cloud coverage, we determine pigments and the red edge could be detected within 1000 hr (100 hr) at distances within 15 pc (11 pc). However, tighter telescope inner working angles (2.5 λ/D) would allow surface biosignature detection at further distances. Anoxygenic photosynthetic biosignatures could also be more easily detectable than nonphotosynthetic pigments and the photosynthetic red edge when compared against a false positive iron oxide slope. Future life detection missions should evaluate the influence of false positives on the detection of multiple surface biosignatures.
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Affiliation(s)
- Schuyler R Borges
- Department of Astronomy and Planetary Science, Northern Arizona University, Flagstaff, Arizona, USA
- Habitability, Atmospheres, and Biosignatures Laboratory, University of Arizona, Tucson, Arizona, USA
| | - Gabrielle G Jones
- Department of Astronomy and Planetary Science, Northern Arizona University, Flagstaff, Arizona, USA
- Habitability, Atmospheres, and Biosignatures Laboratory, University of Arizona, Tucson, Arizona, USA
| | - Tyler D Robinson
- Department of Astronomy and Planetary Science, Northern Arizona University, Flagstaff, Arizona, USA
- Habitability, Atmospheres, and Biosignatures Laboratory, University of Arizona, Tucson, Arizona, USA
- Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona, USA
- NASA Nexus for Exoplanet System Science Virtual Planetary Laboratory, University of Washington, Seattle, Washington, USA
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Tilahun L, Asrat A, Wessel GM, Simachew A. Ancestors in the Extreme: A Genomics View of Microbial Diversity in Hypersaline Aquatic Environments. Results Probl Cell Differ 2024; 71:185-212. [PMID: 37996679 DOI: 10.1007/978-3-031-37936-9_10] [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] [Indexed: 11/25/2023]
Abstract
The origin of eukaryotic cells, and especially naturally occurring syncytial cells, remains debatable. While a majority of our biomedical research focuses on the eukaryotic result of evolution, our data remain limiting on the prokaryotic precursors of these cells. This is particularly evident when considering extremophile biology, especially in how the genomes of organisms in extreme environments must have evolved and adapted to unique habitats. Might these rapidly diversifying organisms have created new genetic tools eventually used to enhance the evolution of the eukaryotic single nuclear or syncytial cells? Many organisms are capable of surviving, or even thriving, in conditions of extreme temperature, acidity, organic composition, and then rapidly adapt to yet new conditions. This study identified organisms found in extremes of salinity. A lake and a nearby pond in the Ethiopian Rift Valley were interrogated for life by sequencing the DNA of populations of organism collected from the water in these sites. Remarkably, a vast diversity of microbes were identified, and even though the two sites were nearby each other, the populations of organisms were distinctly different. Since these microbes are capable of living in what for humans would be inhospitable conditions, the DNA sequences identified should inform the next step in these investigations; what new gene families, or modifications to common genes, do these organisms employ to survive in these extreme conditions. The relationship between organisms and their environment can be revealed by decoding genomes of organisms living in extreme environments. These genomes disclose new biological mechanisms that enable life outside moderate environmental conditions, new gene functions for application in biotechnology, and may even result in identification of new species. In this study, we have collected samples from two hypersaline sites in the Danakil depression, the shorelines of Lake As'ale and an actively mixing salt pond called Muda'ara (MUP), to identify the microbial community by metagenomics. Shotgun sequencing was applied to high density sampling, and the relative abundance of Operational Taxonomic Units (OTUs) was calculated. Despite the broad taxonomic similarities among the salt-saturated metagenomes analyzed, MUP stood out from Lake As'ale samples. In each sample site, Archaea accounted for 95% of the total OTUs, largely to the class Halobacteria. The remaining 5% of organisms were eubacteria, with an unclassified strain of Salinibacter ruber as the dominant OTU in both the Lake and the Pond. More than 40 different genes coding for stress proteins were identified in the three sample sites of Lake As'ale, and more than 50% of the predicted stress-related genes were associated with oxidative stress response proteins. Chaperone proteins (DnaK, DnaJ, GrpE, and ClpB) were predicted, with percentage of query coverage and similarities ranging between 9.5% and 99.2%. Long reads for ClpB homologous protein from Lake As'ale metagenome datasets were modeled, and compact 3D structures were generated. Considering the extreme environmental conditions of the Danakil depression, this metagenomics dataset can add and complement other studies on unique gene functions on stress response mechanisms of thriving bio-communities that could have contributed to cellular changes leading to single and/or multinucleated eukaryotic cells.
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Affiliation(s)
- Lulit Tilahun
- Institute of Biotechnology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Asfawossen Asrat
- Department of Mining and Geological Engineering, Botswana International University of Science and Technology, Palapye, Botswana
- School of Earth Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Gary M Wessel
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, RI, USA.
| | - Addis Simachew
- Institute of Biotechnology, Addis Ababa University, Addis Ababa, Ethiopia
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Paris ER, Arandia-Gorostidi N, Klempay B, Bowman JS, Pontefract A, Elbon CE, Glass JB, Ingall ED, Doran PT, Som SM, Schmidt BE, Dekas AE. Single-cell analysis in hypersaline brines predicts a water-activity limit of microbial anabolic activity. SCIENCE ADVANCES 2023; 9:eadj3594. [PMID: 38134283 PMCID: PMC10745694 DOI: 10.1126/sciadv.adj3594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/22/2023] [Indexed: 12/24/2023]
Abstract
Hypersaline brines provide excellent opportunities to study extreme microbial life. Here, we investigated anabolic activity in nearly 6000 individual cells from solar saltern sites with water activities (aw) ranging from 0.982 to 0.409 (seawater to extreme brine). Average anabolic activity decreased exponentially with aw, with nuanced trends evident at the single-cell level: The proportion of active cells remained high (>50%) even after NaCl saturation, and subsets of cells spiked in activity as aw decreased. Intracommunity heterogeneity in activity increased as seawater transitioned to brine, suggesting increased phenotypic heterogeneity with increased physiological stress. No microbial activity was detected in the 0.409-aw brine (an MgCl2-dominated site) despite the presence of cell-like structures. Extrapolating our data, we predict an aw limit for detectable anabolic activity of 0.540, which is beyond the currently accepted limit of life based on cell division. This work demonstrates the utility of single-cell, metabolism-based techniques for detecting active life and expands the potential habitable space on Earth and beyond.
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Affiliation(s)
- Emily R. Paris
- Department of Earth System Science, Stanford University, Stanford, CA 94305, USA
| | | | - Benjamin Klempay
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA 92037, USA
| | - Jeff S. Bowman
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA 92037, USA
| | | | - Claire E. Elbon
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Jennifer B. Glass
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Ellery D. Ingall
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Peter T. Doran
- Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Sanjoy M. Som
- Blue Marble Space Institute of Science, Seattle, WA 98104, USA
| | - Britney E. Schmidt
- Departments of Astronomy and Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Anne E. Dekas
- Department of Earth System Science, Stanford University, Stanford, CA 94305, USA
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Moopantakath J, Imchen M, Anju VT, Busi S, Dyavaiah M, Martínez-Espinosa RM, Kumavath R. Bioactive molecules from haloarchaea: Scope and prospects for industrial and therapeutic applications. Front Microbiol 2023; 14:1113540. [PMID: 37065149 PMCID: PMC10102575 DOI: 10.3389/fmicb.2023.1113540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 03/14/2023] [Indexed: 04/03/2023] Open
Abstract
Marine environments and salty inland ecosystems encompass various environmental conditions, such as extremes of temperature, salinity, pH, pressure, altitude, dry conditions, and nutrient scarcity. The extremely halophilic archaea (also called haloarchaea) are a group of microorganisms requiring high salt concentrations (2–6 M NaCl) for optimal growth. Haloarchaea have different metabolic adaptations to withstand these extreme conditions. Among the adaptations, several vesicles, granules, primary and secondary metabolites are produced that are highly significant in biotechnology, such as carotenoids, halocins, enzymes, and granules of polyhydroxyalkanoates (PHAs). Among halophilic enzymes, reductases play a significant role in the textile industry and the degradation of hydrocarbon compounds. Enzymes like dehydrogenases, glycosyl hydrolases, lipases, esterases, and proteases can also be used in several industrial procedures. More recently, several studies stated that carotenoids, gas vacuoles, and liposomes produced by haloarchaea have specific applications in medicine and pharmacy. Additionally, the production of biodegradable and biocompatible polymers by haloarchaea to store carbon makes them potent candidates to be used as cell factories in the industrial production of bioplastics. Furthermore, some haloarchaeal species can synthesize nanoparticles during heavy metal detoxification, thus shedding light on a new approach to producing nanoparticles on a large scale. Recent studies also highlight that exopolysaccharides from haloarchaea can bind the SARS-CoV-2 spike protein. This review explores the potential of haloarchaea in the industry and biotechnology as cellular factories to upscale the production of diverse bioactive compounds.
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Affiliation(s)
- Jamseel Moopantakath
- Department of Genomic Science, School of Biological Sciences, Central University of Kerala, Kerala, India
| | - Madangchanok Imchen
- Department of Microbiology, School of Life Sciences, Pondicherry University, Puducherry, India
| | - V. T. Anju
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Puducherry, India
| | - Siddhardha Busi
- Department of Microbiology, School of Life Sciences, Pondicherry University, Puducherry, India
| | - Madhu Dyavaiah
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Puducherry, India
| | - Rosa María Martínez-Espinosa
- Biochemistry, Molecular Biology, Edaphology and Agricultural Chemistry Department, Faculty of Sciences, University of Alicante, Alicante, Spain
- Multidisciplinary Institute for Environmental Studies “Ramón Margalef”, University of Alicante, Alicante, Spain
- Rosa María Martínez-Espinosa,
| | - Ranjith Kumavath
- Department of Genomic Science, School of Biological Sciences, Central University of Kerala, Kerala, India
- Department of Biotechnology, School of Life Sciences, Pondicherry University, Puducherry, India
- *Correspondence: Ranjith Kumavath, ,
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Sierra MA, Ryon KA, Tierney BT, Foox J, Bhattacharya C, Afshin E, Butler D, Green SJ, Thomas WK, Ramsdell J, Bivens NJ, McGrath K, Mason CE, Tighe SW. Microbiome and metagenomic analysis of Lake Hillier Australia reveals pigment-rich polyextremophiles and wide-ranging metabolic adaptations. ENVIRONMENTAL MICROBIOME 2022; 17:60. [PMID: 36544228 PMCID: PMC9768965 DOI: 10.1186/s40793-022-00455-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 12/01/2022] [Indexed: 06/17/2023]
Abstract
Lake Hillier is a hypersaline lake known for its distinctive bright pink color. The cause of this phenomenon in other hypersaline sites has been attributed to halophiles, Dunaliella, and Salinibacter, however, a systematic analysis of the microbial communities, their functional features, and the prevalence of pigment-producing-metabolisms has not been previously studied. Through metagenomic sequencing and culture-based approaches, our results evidence that Lake Hillier is composed of a diverse set of microorganisms including archaea, bacteria, algae, and viruses. Our data indicate that the microbiome in Lake Hillier is composed of multiple pigment-producer microbes, including Dunaliella, Salinibacter, Halobacillus, Psychroflexus, Halorubrum, many of which are cataloged as polyextremophiles. Additionally, we estimated the diversity of metabolic pathways in the lake and determined that many of these are related to pigment production. We reconstructed complete or partial genomes for 21 discrete bacteria (N = 14) and archaea (N = 7), only 2 of which could be taxonomically annotated to previously observed species. Our findings provide the first metagenomic study to decipher the source of the pink color of Australia's Lake Hillier. The study of this pink hypersaline environment is evidence of a microbial consortium of pigment producers, a repertoire of polyextremophiles, a core microbiome and potentially novel species.
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Affiliation(s)
- Maria A Sierra
- Tri-Institutional Computational Biology and Medicine Program, Weill Cornell Medicine, New York, NY, USA
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Krista A Ryon
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Braden T Tierney
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Jonathan Foox
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Chandrima Bhattacharya
- Tri-Institutional Computational Biology and Medicine Program, Weill Cornell Medicine, New York, NY, USA
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Evan Afshin
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Daniel Butler
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Stefan J Green
- Genomics and Microbiome Core Facility, Rush University, New York, IL, USA
| | - W Kelley Thomas
- Department of Molecular, Cellular, and Biomedical Sciences, College of Life Sciences and Agriculture, University of New Hampshire, Durham, NH, USA
| | | | - Nathan J Bivens
- DNA Core Facility, University of Missouri, Columbia, MO, USA
| | | | - Christopher E Mason
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA.
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA.
- WorldQuant Initiative for Quantitative Prediction, Weill Cornell Medicine, New York, NY, USA.
- The Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA.
| | - Scott W Tighe
- Advanced Genomics Laboratory, University of Vermont Cancer Center, University of Vermont, Burlington, VT, USA.
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Wu JH, McGenity TJ, Rettberg P, Simões MF, Li WJ, Antunes A. The archaeal class Halobacteria and astrobiology: Knowledge gaps and research opportunities. Front Microbiol 2022; 13:1023625. [PMID: 36312929 PMCID: PMC9608585 DOI: 10.3389/fmicb.2022.1023625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 09/07/2022] [Indexed: 09/19/2023] Open
Abstract
Water bodies on Mars and the icy moons of the outer solar system are now recognized as likely being associated with high levels of salt. Therefore, the study of high salinity environments and their inhabitants has become increasingly relevant for Astrobiology. Members of the archaeal class Halobacteria are the most successful microbial group living in hypersaline conditions and are recognized as key model organisms for exposure experiments. Despite this, data for the class is uneven across taxa and widely dispersed across the literature, which has made it difficult to properly assess the potential for species of Halobacteria to survive under the polyextreme conditions found beyond Earth. Here we provide an overview of published data on astrobiology-linked exposure experiments performed with members of the Halobacteria, identifying clear knowledge gaps and research opportunities.
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Affiliation(s)
- Jia-Hui Wu
- State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology (MUST), Taipa, Macau SAR, China
- China National Space Administration (CNSA), Macau Center for Space Exploration and Science, Taipa, Macau SAR, China
| | - Terry J. McGenity
- School of Life Sciences, University of Essex, Colchester, United Kingdom
| | - Petra Rettberg
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Köln, Germany
| | - Marta F. Simões
- State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology (MUST), Taipa, Macau SAR, China
- China National Space Administration (CNSA), Macau Center for Space Exploration and Science, Taipa, Macau SAR, China
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - André Antunes
- State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology (MUST), Taipa, Macau SAR, China
- China National Space Administration (CNSA), Macau Center for Space Exploration and Science, Taipa, Macau SAR, China
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Wei XY, Zhu HY, Song L, Zhang RP, Li AH, Niu QH, Liu XZ, Bai FY. Yeast Diversity in the Qaidam Basin Desert in China with the Description of Five New Yeast Species. J Fungi (Basel) 2022; 8:jof8080858. [PMID: 36012846 PMCID: PMC9409814 DOI: 10.3390/jof8080858] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 08/12/2022] [Accepted: 08/13/2022] [Indexed: 11/18/2022] Open
Abstract
The Qaidam Basin is the highest and one of the largest and driest deserts on Earth. It is considered a mars analog area in China. In contrast to numerous studies concerning its geology, geophysical, and chemistry, relatively few studies have reported microbial diversity and distribution in this area. Here, we investigated culturable yeast diversity in the northeast Qaidam Basin. A total of 194 yeast strains were isolated, and 12 genera and 21 species were identified, among which 19 were basidiomycetous yeasts. Naganishia albida, N. adeliensis, and Filobasidium magnum were the three most dominant species and were distributed in thirteen samples from eight locations. Five new species (Filobasidium chaidanensis, Kondoa globosum, Symmetrospora salmoneus, Teunia nitrariae, and Vishniacozyma pseudodimennae) were found and described based on ITS and D1D2 gene loci together with phenotypic characteristics and physiochemical analysis. Representative strains from each species were chosen for the salt-tolerant test, in which species showed different responses to different levels of NaCl concentrations. Further, the strain from soil can adapt well to the higher salt stress compared to those from plants or lichens. Our study represents the first report of the yeast diversity in the Qaidam Basin, including five new species, and also provides further information on the halotolerance of yeasts from the saline environment in mars analog.
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Affiliation(s)
- Xu-Yang Wei
- College of Life Science and Agricultural Engineering, Nanyang Normal University, 1638 Wolong Road, Nanyang 473061, China
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Hai-Yan Zhu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, No.19 (A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Liang Song
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Ri-Peng Zhang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, No.19 (A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Ai-Hua Li
- China General Microbiological Culture Collection Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qiu-Hong Niu
- College of Life Science and Agricultural Engineering, Nanyang Normal University, 1638 Wolong Road, Nanyang 473061, China
| | - Xin-Zhan Liu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- Correspondence: (X.-Z.L.); (F.-Y.B.)
| | - Feng-Yan Bai
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- Correspondence: (X.-Z.L.); (F.-Y.B.)
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8
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Santini TC, Gramenz L, Southam G, Zammit C. Microbial Community Structure Is Most Strongly Associated With Geographical Distance and pH in Salt Lake Sediments. Front Microbiol 2022; 13:920056. [PMID: 35756015 PMCID: PMC9221066 DOI: 10.3389/fmicb.2022.920056] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 05/09/2022] [Indexed: 11/16/2022] Open
Abstract
Salt lakes are globally significant microbial habitats, hosting substantial novel microbial diversity and functional capacity. Extremes of salinity and pH both pose major challenges for survival of microbial life in terrestrial and aquatic environments, and are frequently cited as primary influences on microbial diversity across a wide variety of environments. However, few studies have attempted to identify spatial and geochemical contributions to microbial community composition, functional capacity, and environmental tolerances in salt lakes, limiting exploration of novel halophilic and halotolerant microbial species and their potential biotechnological applications. Here, we collected sediment samples from 16 salt lakes at pH values that ranged from pH 4 to 9, distributed across 48,000 km2 of the Archaean Yilgarn Craton in southwestern Australia to identify associations between environmental factors and microbial community composition, and used a high throughput culturing approach to identify the limits of salt and pH tolerance during iron and sulfur oxidation in these microbial communities. Geographical distance between lakes was the primary contributor to variation in microbial community composition, with pH identified as the most important geochemical contributor to variation in microbial community composition. Microbial community composition split into two clear groups by pH: Bacillota dominated microbial communities in acidic saline lakes, whereas Euryarchaeota dominated microbial communities in alkaline saline lakes. Iron oxidation was observed at salinities up to 160 g L-1 NaCl at pH values as low as pH 1.5, and sulfur oxidation was observed at salinities up to 160 g L-1 NaCl between pH values 2-10, more than doubling previously observed tolerances to NaCl salinity amongst cultivable iron and sulfur oxidizers at these extreme pH values. OTU level diversity in the salt lake microbial communities emerged as the major indicator of iron- and sulfur-oxidizing capacity and environmental tolerances to extremes of pH and salinity. Overall, when bioprospecting for novel microbial functional capacity and environmental tolerances, our study supports sampling from remote, previously unexplored, and maximally distant locations, and prioritizing for OTU level diversity rather than present geochemical conditions.
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Affiliation(s)
- Talitha C. Santini
- UWA School of Agriculture and Environment, The University of Western Australia, Crawley, WA, Australia
| | - Lucy Gramenz
- School of Earth and Environmental Sciences, The University of Queensland, St Lucia, QLD, Australia
| | - Gordon Southam
- School of Earth and Environmental Sciences, The University of Queensland, St Lucia, QLD, Australia
| | - Carla Zammit
- School of Earth and Environmental Sciences, The University of Queensland, St Lucia, QLD, Australia
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Active Microbial Airborne Dispersal and Biomorphs as Confounding Factors for Life Detection in the Cell-Degrading Brines of the Polyextreme Dallol Geothermal Field. mBio 2022; 13:e0030722. [PMID: 35384698 PMCID: PMC9040726 DOI: 10.1128/mbio.00307-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Determining the precise limits of life in polyextreme environments is challenging. Studies along gradients of polyextreme conditions in the Dallol proto-volcano area (Danakil salt desert, Ethiopia) showed the occurrence of archaea-dominated communities (up to 99%) in several hypersaline systems but strongly suggested that life did not thrive in the hyperacidic (pH ∼0), hypersaline (∼35% [wt/vol],) and sometimes hot (up to 108°C) ponds of the Dallol dome. However, it was recently claimed that archaea flourish in these brines based on the detection of one Nanohaloarchaeotas 16S rRNA gene and fluorescent in situ hybridization (FISH) experiments with archaea-specific probes. Here, we characterized the diversity of microorganisms in aerosols over Dallol, and we show that, in addition to typical bacteria from soil/dust, they transport halophilic archaea likely originating from neighboring hypersaline ecosystems. We also show that cells and DNA from cultures and natural local halophilic communities are rapidly destroyed upon contact with Dallol brine. Furthermore, we confirm the widespread occurrence of mineral particles, including silica-based biomorphs, in Dallol brines. FISH experiments using appropriate controls show that DNA fluorescent probes and dyes unspecifically bind to mineral precipitates in Dallol brines; cellular morphologies were unambiguously observed only in nearby hypersaline ecosystems. Our results show that airborne cell dispersal and unspecific binding of fluorescent probes are confounding factors likely affecting previous inferences of archaea thriving in Dallol. They highlight the need for controls and the consideration of alternative abiotic explanations before safely drawing conclusions about the presence of life in polyextreme terrestrial or extraterrestrial systems.
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Abstract
Water is the cellular milieu, drives all biochemistry within Earth's biosphere and facilitates microbe-mediated decay processes. Instead of reviewing these topics, the current article focuses on the activities of water as a preservative-its capacity to maintain the long-term integrity and viability of microbial cells-and identifies the mechanisms by which this occurs. Water provides for, and maintains, cellular structures; buffers against thermodynamic extremes, at various scales; can mitigate events that are traumatic to the cell membrane, such as desiccation-rehydration, freeze-thawing and thermal shock; prevents microbial dehydration that can otherwise exacerbate oxidative damage; mitigates against biocidal factors (in some circumstances reducing ultraviolet radiation and diluting solute stressors or toxic substances); and is effective at electrostatic screening so prevents damage to the cell by the intense electrostatic fields of some ions. In addition, the water retained in desiccated cells (historically referred to as 'bound' water) plays key roles in biomacromolecular structures and their interactions even for fully hydrated cells. Assuming that the components of the cell membrane are chemically stable or at least repairable, and the environment is fairly constant, water molecules can apparently maintain membrane geometries over very long periods provided these configurations represent thermodynamically stable states. The spores and vegetative cells of many microbes survive longer in the presence of vapour-phase water (at moderate-to-high relative humidities) than under more-arid conditions. There are several mechanisms by which large bodies of water, when cooled during subzero weather conditions remain in a liquid state thus preventing potentially dangerous (freeze-thaw) transitions for their microbiome. Microbial life can be preserved in pure water, freshwater systems, seawater, brines, ice/permafrost, sugar-rich aqueous milieux and vapour-phase water according to laboratory-based studies carried out over periods of years to decades and some natural environments that have yielded cells that are apparently thousands, or even (for hypersaline fluid inclusions of mineralized NaCl) hundreds of millions, of years old. The term preservative has often been restricted to those substances used to extend the shelf life of foods (e.g. sodium benzoate, nitrites and sulphites) or those used to conserve dead organisms, such as ethanol or formaldehyde. For living microorganisms however, the ultimate preservative may actually be water. Implications of this role are discussed with reference to the ecology of halophiles, human pathogens and other microbes; food science; biotechnology; biosignatures for life and other aspects of astrobiology; and the large-scale release/reactivation of preserved microbes caused by global climate change.
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Affiliation(s)
- John E. Hallsworth
- Institute for Global Food SecuritySchool of Biological SciencesQueen’s University Belfast19 Chlorine GardensBelfastBT9 5DLUK
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11
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Belilla J, Iniesto M, Moreira D, Benzerara K, López-García JM, López-Archilla AI, Reboul G, Deschamps P, Gérard E, López-García P. Archaeal overdominance close to life-limiting conditions in geothermally influenced hypersaline lakes at the Danakil Depression, Ethiopia. Environ Microbiol 2021; 23:7168-7182. [PMID: 34519149 DOI: 10.1111/1462-2920.15771] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/05/2021] [Accepted: 09/08/2021] [Indexed: 01/04/2023]
Abstract
The Dallol protovolcanic area on the Danakil Depression (Afar region, Ethiopia) exhibits unique hydrothermal manifestations in hypersaline context, yielding varied polyextreme physicochemical conditions. Previous studies identified a wide archaeal diversity in less extreme brines but failed to identify microorganisms thriving in either high-chaotropicity, low-water-activity brines or hyperacidic-hypersaline Na-Fe-rich brines. Recently, we accessed several small lakes under intense degassing activity adjacent to the Round Mountain, west to the Dallol dome [Western Canyon Lakes (WCL); WCL1-5]. They exhibited intermediate parameter combinations (pH ~ 5, 34%-41% (weight/volume) NaCl-dominated salts with relatively high levels of chaotropic Mg-Ca salts) that should allow to better constrain life limits. These lakes were overwhelmingly dominated by Archaea, encompassing up to 99% of prokaryotic 16S rRNA gene amplicon sequences in metabarcoding studies. The majority belonged to Halobacteriota and Nanohaloarchaeota, the latter representing up to half of prokaryotic sequences. Optical and epifluorescence microscopy showed active cells in natural samples and diverse morphotypes in enrichment cultures. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy revealed tiny cells (200-300 nm diameter) epibiotically associated with somewhat larger cells (0.6-1 μm) but also the presence of silica-dominated precipitates of similar size and shape, highlighting the difficulty of distinguishing microbes from mineral biomorphs in this kind of low-biomass systems.
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Affiliation(s)
- Jodie Belilla
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Miguel Iniesto
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - David Moreira
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Karim Benzerara
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, CNRS, Sorbonne Université, Muséum National d'Histoire Naturelle, Paris, France
| | | | | | - Guillaume Reboul
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Philippe Deschamps
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | | | - Purificación López-García
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
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12
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Ghori NUH, Wise MJ, Whiteley AS. Temporal Microbial Community Dynamics Within a Unique Acid Saline Lake. Front Microbiol 2021; 12:649594. [PMID: 34248867 PMCID: PMC8264302 DOI: 10.3389/fmicb.2021.649594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 06/04/2021] [Indexed: 11/13/2022] Open
Abstract
Lake Magic is an extremely acidic, hypersaline lake found in Western Australia, with the highest concentrations of aluminum and silica in the world. Previous studies of Lake Magic diversity have revealed that the lake hosts acid- and halotolerant bacterial and fungal species. However, they have not canvassed microbial population dynamics across flooding, evapo-concentration and desiccation stages. In this study, we used amplicon sequencing and potential function prediction on sediment and salt mat samples. We observed that the bacterial and fungal diversity in Lake Magic is strongly driven by carbon, temperature, pH and salt concentrations at the different stages of the lake. We also saw that the fungal diversity decreased as the environmental conditions became more extreme. However, prokaryotic diversity was very dynamic and bacteria dominated archaeal species, both in abundance and diversity, perhaps because bacteria better tolerate the extreme variation in conditions. Bacterial species diversity was the highest during early flooding stage and decreased during more stressful conditions. We observed an increase in acid tolerant and halotolerant species in the sediment, involved in functions such as sulfur and iron metabolism, i.e., species involved in buffering the external environment. Thus, due to activity within the microbial community, the environmental conditions in the sediment do not change to the same degree as conditions in the salt mat, resulting in the sediment becoming a safe haven for microbes, which are able to thrive during the extreme conditions of the evapo-concentration and desiccation stages.
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Affiliation(s)
- Noor-Ul-Huda Ghori
- School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia.,The Marshall Centre of Infectious Diseases, School of Biological Sciences, The University of Western Australia, Perth, WA, Australia
| | - Michael J Wise
- The Marshall Centre of Infectious Diseases, School of Biological Sciences, The University of Western Australia, Perth, WA, Australia.,Department of Computer Science and Engineering, The University of Western Australia, Perth, WA, Australia
| | - Andrew S Whiteley
- School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia.,Centre for Environment and Life Sciences, CSIRO Land Water, Perth, WA, Australia
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13
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Benison KC, O'Neill WK, Blain D, Hallsworth JE. Water Activities of Acid Brine Lakes Approach the Limit for Life. ASTROBIOLOGY 2021; 21:729-740. [PMID: 33819431 PMCID: PMC8219186 DOI: 10.1089/ast.2020.2334] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 02/09/2021] [Indexed: 05/19/2023]
Abstract
Water activity is an important characteristic for describing unusual waters and is a determinant of habitability for microorganisms. However, few empirical studies of water activity have been done for natural waters exhibiting an extreme chemistry. Here, we investigate water activity for acid brines from Western Australia and Chile with pH as low as 1.4, salinities as high as 32% total dissolved solids, and complex chemical compositions. These acid brines host diverse communities of extremophilic microorganisms, including archaea, bacteria, algae, and fungi, according to metagenomic analyses. For the most extreme brine, its water activity (0.714) was considerably lower than that of saturated (pure) NaCl brine. This study provides a thermodynamic insight into life within end-member natural waters that lie at, or possibly beyond, the very edge of habitable space on Earth.
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Affiliation(s)
- Kathleen C. Benison
- Department of Geology and Geography, West Virginia University, Morgantown, West Virginia, USA
- Address correspondence to: Kathleen C. Benison, Department of Geology and Geography, West Virginia University, Morgantown, WV 26506-6300, USA
| | - William K. O'Neill
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland
| | - David Blain
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland
| | - John E. Hallsworth
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland
- Address correspondence to: John E. Hallsworth, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Garden, Belfast, BT9 5DL, Northern Ireland
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14
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Matarredona L, Camacho M, Zafrilla B, Bonete MJ, Esclapez J. The Role of Stress Proteins in Haloarchaea and Their Adaptive Response to Environmental Shifts. Biomolecules 2020; 10:biom10101390. [PMID: 33003558 PMCID: PMC7601130 DOI: 10.3390/biom10101390] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/18/2020] [Accepted: 09/24/2020] [Indexed: 12/26/2022] Open
Abstract
Over the years, in order to survive in their natural environment, microbial communities have acquired adaptations to nonoptimal growth conditions. These shifts are usually related to stress conditions such as low/high solar radiation, extreme temperatures, oxidative stress, pH variations, changes in salinity, or a high concentration of heavy metals. In addition, climate change is resulting in these stress conditions becoming more significant due to the frequency and intensity of extreme weather events. The most relevant damaging effect of these stressors is protein denaturation. To cope with this effect, organisms have developed different mechanisms, wherein the stress genes play an important role in deciding which of them survive. Each organism has different responses that involve the activation of many genes and molecules as well as downregulation of other genes and pathways. Focused on salinity stress, the archaeal domain encompasses the most significant extremophiles living in high-salinity environments. To have the capacity to withstand this high salinity without losing protein structure and function, the microorganisms have distinct adaptations. The haloarchaeal stress response protects cells against abiotic stressors through the synthesis of stress proteins. This includes other heat shock stress proteins (Hsp), thermoprotectants, survival proteins, universal stress proteins, and multicellular structures. Gene and family stress proteins are highly conserved among members of the halophilic archaea and their study should continue in order to develop means to improve for biotechnological purposes. In this review, all the mechanisms to cope with stress response by haloarchaea are discussed from a global perspective, specifically focusing on the role played by universal stress proteins.
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15
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Bishop JL, Gross C, Danielsen J, Parente M, Murchie SL, Horgan B, Wray JJ, Viviano C, Seelos FP. Multiple mineral horizons in layered outcrops at Mawrth Vallis, Mars, signify changing geochemical environments on early Mars. ICARUS 2020; 341:113634. [PMID: 34045770 PMCID: PMC8152300 DOI: 10.1016/j.icarus.2020.113634] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Refined calibrations of CRISM images are enabling identification of smaller deposits of unique aqueous materials on Mars that reveal changing environmental conditions at the region surrounding Mawrth Vallis. Through characterization of these clay-sulfate assemblages and their association with the layered, phyllosilicate units of this region, more details of the aqueous geochemical history can be gleaned. A stratigraphy including five distinct mineral horizons is mapped using compositional data from CRISM over CTX and HRSC imagery across 100s of km and from CRISM over HiRISE imagery across 100s of meters. Transitions in mineralogic units were characterized using visible/near-infrared (VNIR) spectral properties and surface morphology. We identified and characterized complex "doublet" type spectral signatures with two bands between 2.2 and 2.3 μm at one stratigraphic horizon. Based on comparisons with terrestrial sites, the spectral "doublet" unit described here may reflect the remnants of a salty, evaporative period that existed on Mars during the transition from formation of Fe-rich phyllosilicates to Al-rich phyllosilicates. Layered outcrops observed at Mawrth Vallis are thicker than in other altered regions of Mars, but may represent processes that were more widespread in wet regions of the planet during its early history. The aqueous geochemical environments supporting the outcrops observed here include: (i) the formation of Fe3+-rich smectites in a warm and wet environment, (ii) overlain by a thin ferrous-bearing clay unit that could be associated with heating or reducing conditions, (iii) followed by a transition to salty and/or acidic alteration phases and sulfates (characterized by the spectral "doublet" shape) in an evaporative setting, (iv) formation of Al-rich phyllosilicates through pedogenesis or acid leaching, and (v) finally persistence of poorly crystalline aluminosilicates marking the end of the warm climate on early Mars. The "doublet" type units described here are likely composed of clay-sulfate assemblages formed in saline, acidic evaporative environments similar to those found in Western Australia and the Atacama desert. Despite the chemically extreme and variable waters present at these terrestrial, saline lake environments, active ecosystems are present; thus, these "doublet" type units may mark exciting areas for continued exploration important to astrobiology on Mars.
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Affiliation(s)
- Janice L. Bishop
- SETI Institute, Mountain View, CA, United States of America
- Freie Universität Berlin, Berlin, Germany
| | | | - Jacob Danielsen
- SETI Institute, Mountain View, CA, United States of America
- San Jose State University, San Jose, CA, United States of America
| | - Mario Parente
- University of Massachusetts at Amherst, Amherst, MA, United States of America
| | - Scott L. Murchie
- Johns Hopkins University Applied Physics Lab, Laurel, MD, United States of America
| | - Briony Horgan
- Purdue University, West Lafayette, IN, United States of America
| | - James J. Wray
- Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Christina Viviano
- Johns Hopkins University Applied Physics Lab, Laurel, MD, United States of America
| | - Frank P. Seelos
- Johns Hopkins University Applied Physics Lab, Laurel, MD, United States of America
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16
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Johnson SS, Millan M, Graham H, Benison KC, Williams AJ, McAdam A, Knudson CA, Andrejkovičová S, Achilles C. Lipid Biomarkers in Ephemeral Acid Salt Lake Mudflat/Sandflat Sediments: Implications for Mars. ASTROBIOLOGY 2020; 20:167-178. [PMID: 32022603 DOI: 10.1089/ast.2017.1812] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Sedimentary strata on Mars often contain a mix of sulfates, iron oxides, chlorides, and phyllosilicates, a mineral assemblage that is unique on Earth to acid brine environments. To help characterize the astrobiological potential of depositional environments with similar minerals present, samples from four naturally occurring acidic salt lakes and adjacent mudflats/sandflats in the vicinity of Norseman, Western Australia, were collected and analyzed. Lipid biomarkers were extracted and quantified, revealing biomarkers from vascular plants alongside trace microbial lipids. The resilience of lipids from dead organic material in these acid saline sediments through the pervasive stages of early diagenesis lends support to the idea that sulfates, in tandem with phyllosilicates and iron oxides, could be a viable target for biomarkers on Mars. To fully understand the astrobiological potential of these depositional environments, additional investigations of organic preservation in ancient acidic saline sedimentary environments are needed.
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Affiliation(s)
- Sarah Stewart Johnson
- Department of Biology, Georgetown University, Washington, District of Columbia
- Program on Science, Technology, and International Affairs, Georgetown University, Washington, District of Columbia
| | - Maëva Millan
- Department of Biology, Georgetown University, Washington, District of Columbia
- NASA Goddard Space Flight Center, Greenbelt, Maryland
| | | | - Kathleen C Benison
- Department of Geology and Geography, West Virginia University, Morgantown, West Virginia
| | - Amy J Williams
- Department of Geological Sciences, University of Florida, Gainesville, Florida
| | - Amy McAdam
- NASA Goddard Space Flight Center, Greenbelt, Maryland
| | - Christine A Knudson
- NASA Goddard Space Flight Center, Greenbelt, Maryland
- Center for Research and Exploration in Space Sciences and Technology/University of Maryland College Park, College Park, Maryland
| | - Slavka Andrejkovičová
- NASA Goddard Space Flight Center, Greenbelt, Maryland
- Center for Research and Exploration in Space Sciences and Technology/University of Maryland College Park, College Park, Maryland
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17
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Aerts JW, van Spanning RJM, Flahaut J, Molenaar D, Bland PA, Genge MJ, Ehrenfreund P, Martins Z. Microbial Communities in Sediments From Four Mildly Acidic Ephemeral Salt Lakes in the Yilgarn Craton (Australia) - Terrestrial Analogs to Ancient Mars. Front Microbiol 2019; 10:779. [PMID: 31133990 PMCID: PMC6512757 DOI: 10.3389/fmicb.2019.00779] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 03/27/2019] [Indexed: 11/24/2022] Open
Abstract
The Yilgarn Craton in Australia has a large number of naturally occurring shallow ephemeral lakes underlain by a dendritic system of paleodrainage channels. Processes like evaporation, flooding, erosion, as well as inflow of saline, often acidic and ion-rich groundwater contribute to the (dynamic) nature of the lakes and the composition of the sediments. The region has previously been described as an analog environment for early Mars due to its geological and geophysical similarities. Here, we investigated sediment samples of four lake environments aimed at getting a fundamental understanding of the native microbial communities and the mineralogical and (bio)chemical composition of the sediments they are associated with. The dominant mineral phases in the sediments were quartz, feldspars and amphiboles, while halite and gypsum were the only evaporites detected. Element analysis revealed a rich and complex image, in which silicon, iron, and aluminum were the dominant ions, but relative high concentrations of trace elements such as strontium, chromium, zirconium, and barium were also found. The concentrations of organic carbon, nitrogen, and phosphorus were generally low. 16S amplicon sequencing on the Illumina platform showed the presence of diverse microbial communities in all four lake environments. We found that most of the communities were dominated by extremely halophilic Archaea of the Halobacteriaceae family. The dynamic nature of these lakes appears to influence the biological, biochemical, and geological components of the ecosystem to a large effect. Inter- and intra-lake variations in the distributions of microbial communities were significant, and could only to a minor degree be explained by underlying environmental conditions. The communities are likely significantly influenced by small scale local effects caused by variations in geological settings and dynamic interactions caused by aeolian transport and flooding and evaporation events.
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Affiliation(s)
- Joost W Aerts
- Department of Molecular Cell Biology, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Rob J M van Spanning
- Department of Molecular Cell Biology, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Jessica Flahaut
- Centre de Recherches Pétrographiques et Géochimiques, Centre National de la Recherche Scientifique/Université de Lorraine, Vandœuvre-lès-Nancy, France
| | - Douwe Molenaar
- Department of Molecular Cell Biology, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Phil A Bland
- Department of Applied Geology, Curtin University, Perth, WA, Australia
| | - Matt J Genge
- Department of Earth Science and Engineering, Faculty of Engineering, Imperial College London, London, United Kingdom
| | - Pascale Ehrenfreund
- Leiden Observatory, Leiden University, Leiden, Netherlands.,Space Policy Institute, Elliott School of International Affairs, George Washington University, Washington, DC, United States
| | - Zita Martins
- Centro de Química-Física Molecular-Institute of Nanoscience and Nanotechnology (CQFM-IN), Institute for Bioengineering and Biosciences (iBB), Departamento de Engenharia Química, Instituto Superior Técnico (IST), Universidade de Lisboa, Lisbon, Portugal
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18
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Chan MA, Bowen BB, Corsetti FA, Farrand WH, Law ES, Newsom HE, Perl SM, Spear JR, Thompson DR. Exploring, Mapping, and Data Management Integration of Habitable Environments in Astrobiology. Front Microbiol 2019; 10:147. [PMID: 30891006 PMCID: PMC6412026 DOI: 10.3389/fmicb.2019.00147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 01/21/2019] [Indexed: 11/17/2022] Open
Abstract
New approaches to blending geoscience, planetary science, microbiology-geobiology/ecology, geoinformatics and cyberinfrastructure technology disciplines in a holistic effort can be transformative to astrobiology explorations. Over the last two decades, overwhelming orbital evidence has confirmed the abundance of authigenic (in situ, formed in place) minerals on Mars. On Earth, environments where authigenic minerals form provide a substrate for the preservation of microbial life. Similarly, extraterrestrial life is likely to be preserved where crustal minerals can record and preserve the biochemical mechanisms (i.e., biosignatures). The search for astrobiological evidence on Mars has focused on identifying past or present habitable environments - places that could support some semblance of life. Thus, authigenic minerals represent a promising habitable environment where extraterrestrial life could be recorded and potentially preserved over geologic time scales. Astrobiology research necessarily takes place over vastly different scales; from molecules to viruses and microbes to those of satellites and solar system exploration, but the differing scales of analyses are rarely connected quantitatively. The mismatch between the scales of these observations- from the macro- satellite mineralogical observations to the micro- microbial observations- limits the applicability of our astrobiological understanding as we search for records of life beyond Earth. Each-scale observation requires knowledge of the geologic context and the environmental parameters important for assessing habitability. Exploration efforts to search for extraterrestrial life should attempt to quantify both the geospatial context and the temporal/spatial relationships between microbial abundance and diversity within authigenic minerals at multiple scales, while assimilating resolutions from satellite observations to field measurements to microscopic analyses. Statistical measures, computer vision, and the geospatial synergy of Geographic Information Systems (GIS), can allow analyses of objective data-driven methods to locate, map, and predict where the "sweet spots" of habitable environments occur at multiple scales. This approach of science information architecture or an "Astrobiology Information System" can provide the necessary maps to guide researchers to discoveries via testing, visualizing, documenting, and collaborating on significant data relationships that will advance explorations for evidence of life in our solar system and beyond.
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Affiliation(s)
- Marjorie A. Chan
- Department of Geology and Geophysics, The University of Utah, Salt Lake City, UT, United States
| | - Brenda B. Bowen
- Department of Geology and Geophysics, The University of Utah, Salt Lake City, UT, United States
| | - Frank A. Corsetti
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States
| | | | - Emily S. Law
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States
| | - Horton E. Newsom
- Department Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM, United States
| | - Scott M. Perl
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States
| | - John R. Spear
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, United States
| | - David R. Thompson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States
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19
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A thiotrophic microbial community in an acidic brine lake in Northern Chile. Antonie van Leeuwenhoek 2018; 111:1403-1419. [PMID: 29748902 DOI: 10.1007/s10482-018-1087-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 04/12/2018] [Indexed: 10/16/2022]
Abstract
The endorheic basins of the Northern Chilean Altiplano contain saline lakes and salt flats. Two of the salt flats, Gorbea and Ignorado, have high acidic brines. The causes of the local acidity have been attributed to the occurrence of volcanic native sulfur, the release of sulfuric acid by oxidation, and the low buffering capacity of the rocks in the area. Understanding the microbial community composition and available energy in this pristine ecosystem is relevant in determining the origin of the acidity and in supporting the rationale of conservation policies. Besides, a comparison between similar systems in Australia highlights key microbial components and specific ones associated with geological settings and environmental conditions. Sediment and water samples from the Salar de Gorbea were collected, physicochemical parameters measured and geochemical and molecular biological analyses performed. A low diversity microbial community was observed in brines and sediments dominated by Actinobacteria, Algae, Firmicutes and Proteobacteria. Most of the constituent genera have been reported to be either sulfur oxidizing microorganisms or ones having the potential for sulfur oxidation given available genomic data and information drawn from the literature on cultured relatives. In addition, a link between sulfur oxidation and carbon fixation was observed. In contrast, to acid mine drainage communities, Gorbea microbial diversity is mainly supported by chemolithoheterotrophic, facultative chemolithoautotrophic and oligotrophic sulfur oxidizing populations indicating that microbial activity should also be considered as a causative agent of local acidity.
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20
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Zaikova E, Benison KC, Mormile MR, Johnson SS. Microbial communities and their predicted metabolic functions in a desiccating acid salt lake. Extremophiles 2018; 22:367-379. [PMID: 29350297 DOI: 10.1007/s00792-018-1000-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 01/02/2018] [Indexed: 11/30/2022]
Abstract
The waters of Lake Magic in Western Australia are among the most geochemically extreme on Earth. This ephemeral saline lake is characterized by pH as low as 1.6 salinity as high as 32% total dissolved solids, and unusually complex geochemistry, including extremely high concentrations of aluminum, silica, and iron. We examined the microbial composition and putative function in this extreme acid brine environment by analyzing lake water, groundwater, and sediment samples collected during the austral summer near peak evapoconcentration. Our results reveal that the lake water metagenome, surprisingly, was comprised of mostly eukaryote sequences, particularly fungi and to a lesser extent, green algae. Groundwater and sediment samples were dominated by acidophilic Firmicutes, with eukaryotic community members only detected at low abundances. The lake water bacterial community was less diverse than that in groundwater and sediment, and was overwhelmingly represented by a single OTU affiliated with Salinisphaera. Pathways associated with halotolerance were found in the metagenomes, as were genes associated with biosynthesis of protective carotenoids. During periods of complete desiccation of the lake, we hypothesize that dormancy and entrapment in fluid inclusions in halite crystals may increase long-term survival, leading to the resilience of complex eukaryotes in this extreme environment.
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Affiliation(s)
- Elena Zaikova
- Department of Biology, Georgetown University, Washington, USA
| | - Kathleen C Benison
- Department of Geology and Geography, West Virginia University, Morgantown, USA
| | - Melanie R Mormile
- Department of Biology, Missouri University of Science and Technology, Rolla, USA
| | - Sarah Stewart Johnson
- Department of Biology, Georgetown University, Washington, USA. .,Program on Science, Technology, and International Affairs, Georgetown University, Washington, USA.
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21
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Quatrini R, Escudero LV, Moya-Beltrán A, Galleguillos PA, Issotta F, Acosta M, Cárdenas JP, Nuñez H, Salinas K, Holmes DS, Demergasso C. Draft genome sequence of Acidithiobacillus thiooxidans CLST isolated from the acidic hypersaline Gorbea salt flat in northern Chile. Stand Genomic Sci 2017; 12:84. [PMID: 29270251 PMCID: PMC5735861 DOI: 10.1186/s40793-017-0305-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 12/06/2017] [Indexed: 01/16/2023] Open
Abstract
10.1601/nm.2199 CLST is an extremely acidophilic gamma-proteobacteria that was isolated from the Gorbea salt flat, an acidic hypersaline environment in northern Chile. This kind of environment is considered a terrestrial analog of ancient Martian terrains and a source of new material for biotechnological applications. 10.1601/nm.2199 plays a key role in industrial bioleaching; it has the capacity of generating and maintaining acidic conditions by producing sulfuric acid and it can also remove sulfur layers from the surface of minerals, which are detrimental for their dissolution. CLST is a strain of 10.1601/nm.2199 able to tolerate moderate chloride concentrations (up to 15 g L-1 Cl-), a feature that is quite unusual in extreme acidophilic microorganisms. Basic microbiological features and genomic properties of this biotechnologically relevant strain are described in this work. The 3,974,949 bp draft genome is arranged into 40 scaffolds of 389 contigs containing 3866 protein-coding genes and 75 RNAs encoding genes. This is the first draft genome of a halotolerant 10.1601/nm.2199 strain. The release of the genome sequence of this strain improves representation of these extreme acidophilic Gram negative bacteria in public databases and strengthens the framework for further investigation of the physiological diversity and ecological function of 10.1601/nm.2199 populations.
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Affiliation(s)
- Raquel Quatrini
- Fundación Ciencia & Vida, Av. Zañartu 1482, 7780272 Santiago, Chile
| | - Lorena V. Escudero
- Centro de Biotecnología “Profesor Alberto Ruiz”, Universidad Católica del Norte, 1270709 Antofagasta, Chile
- Centro de Investigación Científica y Tecnológica para la Minería, Antofagasta, Chile
| | - Ana Moya-Beltrán
- Fundación Ciencia & Vida, Av. Zañartu 1482, 7780272 Santiago, Chile
| | - Pedro A. Galleguillos
- Centro de Biotecnología “Profesor Alberto Ruiz”, Universidad Católica del Norte, 1270709 Antofagasta, Chile
- Centro de Investigación Científica y Tecnológica para la Minería, Antofagasta, Chile
| | | | - Mauricio Acosta
- Centro de Biotecnología “Profesor Alberto Ruiz”, Universidad Católica del Norte, 1270709 Antofagasta, Chile
| | | | - Harold Nuñez
- Fundación Ciencia & Vida, Av. Zañartu 1482, 7780272 Santiago, Chile
| | | | - David S. Holmes
- Fundación Ciencia & Vida, Av. Zañartu 1482, 7780272 Santiago, Chile
- Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile
| | - Cecilia Demergasso
- Centro de Biotecnología “Profesor Alberto Ruiz”, Universidad Católica del Norte, 1270709 Antofagasta, Chile
- Centro de Investigación Científica y Tecnológica para la Minería, Antofagasta, Chile
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Megaw J, Gilmore BF. Archaeal Persisters: Persister Cell Formation as a Stress Response in Haloferax volcanii. Front Microbiol 2017; 8:1589. [PMID: 28871247 PMCID: PMC5566976 DOI: 10.3389/fmicb.2017.01589] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 08/04/2017] [Indexed: 12/12/2022] Open
Abstract
Persister cells are phenotypic variants within a microbial population, which are dormant and transiently tolerant to stress. Persistence has been studied extensively in bacteria, and in eukaryotes to a limited extent, however, it has never been observed in archaea. Using the model haloarchaeon, Haloferax volcanii DS2, we demonstrated persister cell formation in this domain, with time-kill curves exhibiting a characteristic biphasic pattern following starvation or exposure to lethal concentrations of various biocidal compounds. Repeated challenges of surviving cells showed that, as with bacteria, persister formation in H. volcanii was not heritable. Additionally, as previously shown with bacteria, persister formation in H. volcanii was suppressed by exogenous indole. The addition of spent culture media to assays conducted on planktonic cells showed that H. volcanii-conditioned media stimulated persistence, whereas conditioned media of other haloarchaea or halophilic bacteria did not, suggesting the involvement of a species-specific signal. Using a TLC overlay assay, the quorum sensing bioreporter Agrobacterium tumefaciens ATCC BAA-2240 detected the presence of C4 and C6 acyl homoserine lactone-like signal molecules in a H. volcanii culture extract. While synthetic bacterial AHLs did not induce persistence, this is potentially due to structural differences between bacterial and archaeal signals, and does not discount a quorum sensing component in haloarchaeal persister formation. The observation of persister cell formation by this haloarchaeon may provide some insights into the survival of these organisms in stressful or dynamic environments.
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Affiliation(s)
- Julianne Megaw
- Biofilm Research Group, School of Pharmacy, Queen's University BelfastBelfast, United Kingdom
| | - Brendan F Gilmore
- Biofilm Research Group, School of Pharmacy, Queen's University BelfastBelfast, United Kingdom
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Paul VG, Mormile MR. A case for the protection of saline and hypersaline environments: a microbiological perspective. FEMS Microbiol Ecol 2017; 93:3950317. [DOI: 10.1093/femsec/fix091] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 07/09/2017] [Indexed: 11/12/2022] Open
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24
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Haferburg G, Gröning JAD, Schmidt N, Kummer NA, Erquicia JC, Schlömann M. Microbial diversity of the hypersaline and lithium-rich Salar de Uyuni, Bolivia. Microbiol Res 2017; 199:19-28. [PMID: 28454706 DOI: 10.1016/j.micres.2017.02.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 02/25/2017] [Indexed: 10/20/2022]
Abstract
Salar de Uyuni, situated in the Southwest of the Bolivian Altiplano, is the largest salt flat on Earth. Brines of this athalassohaline hypersaline environment are rich in lithium and boron. Due to the ever- increasing commodity demand, the industrial exploitation of brines for metal recovery from the world's biggest lithium reservoir is likely to increase substantially in the near future. Studies on the composition of halophilic microbial communities in brines of the salar have not been published yet. Here we report for the first time on the prokaryotic diversity of four brine habitats across the salar. The brine is characterized by salinity values between 132 and 177 PSU, slightly acidic to near-neutral pH and lithium and boron concentrations of up to 2.0 and 1.4g/L, respectively. Community analysis was performed after sequencing the V3-V4 region of the 16S rRNA genes employing the Illumina MiSeq technology. The mothur software package was used for sequence processing and data analysis. Metagenomic analysis revealed the occurrence of an exclusively archaeal community comprising 26 halobacterial genera including only recently identified genera like Halapricum, Halorubellus and Salinarchaeum. Despite the high diversity of the halobacteria-dominated community in sample P3 (Shannon-Weaver index H'=3.12 at 3% OTU cutoff) almost 40% of the Halobacteriaceae-assigned sequences could not be classified on the genus level under stringent filtering conditions. Even if the limited taxonomic resolution of the V3-V4 region for halobacteria is considered, it seems likely to discover new, hitherto undescribed genera of the family halobacteriaceae in this particular habitat of Salar de Uyuni in future.
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Affiliation(s)
- Götz Haferburg
- Interdisciplinary Ecological Center, Environmental Microbiology Group, TU Bergakademie Freiberg, Leipziger Strasse 29, 09599 Freiberg, Germany.
| | | | - Nadja Schmidt
- Institute of Hydrogeology and Environmental Geology, TU Bergakademie Freiberg, Gustav-Zeuner-Straße 12, 09599 Freiberg, Germany
| | - Nicolai-Alexeji Kummer
- Institute of Hydrogeology and Environmental Geology, TU Bergakademie Freiberg, Gustav-Zeuner-Straße 12, 09599 Freiberg, Germany
| | | | - Michael Schlömann
- Interdisciplinary Ecological Center, Environmental Microbiology Group, TU Bergakademie Freiberg, Leipziger Strasse 29, 09599 Freiberg, Germany
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Ruecker A, Schröder C, Byrne J, Weigold P, Behrens S, Kappler A. Geochemistry and Mineralogy of Western Australian Salt Lake Sediments: Implications for Meridiani Planum on Mars. ASTROBIOLOGY 2016; 16:525-538. [PMID: 27258848 DOI: 10.1089/ast.2015.1429] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
UNLABELLED Hypersaline lakes are characteristic for Western Australia and display a rare combination of geochemical and mineralogical properties that make these lakes potential analogues for past conditions on Mars. In our study, we focused on the geochemistry and mineralogy of Lake Orr and Lake Whurr. While both lakes are poor in organic carbon (<1%), the sediments' pH values differ and range from 3.8 to 4.8 in Lake Orr and from 5.4 to 6.3 in Lake Whurr sediments. Lake Whurr sediments were dominated by orange and red sediment zones in which the main Fe minerals were identified as hematite, goethite, and tentatively jarosite and pyrite. Lake Orr was dominated by brownish and blackish sediments where the main Fe minerals were goethite and another paramagnetic Fe(III)-phase that could not be identified. Furthermore, a likely secondary Fe(II)-phase was observed in Lake Orr sediments. The mineralogy of these two salt lakes in the sampling area is strongly influenced by events such as flooding, evaporation, and desiccation, processes that explain at least to some extent the observed differences between Lake Orr and Lake Whurr. The iron mineralogy of Lake Whurr sediments and the high salinity make this lake a suitable analogue for Meridiani Planum on Mars, and in particular the tentative identification of pyrite in Lake Whurr sediments has implications for the interpretation of the Fe mineralogy of Meridiani Planum sediments. KEY WORDS Western Australia-Salt lakes-Jarosite-Hematite-Pyrite-Mars analogue. Astrobiology 16, 525-538.
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Affiliation(s)
- A Ruecker
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
| | - C Schröder
- 2 Biological and Environmental Sciences, School of Natural Sciences, University of Stirling , Stirling, Scotland, UK
| | - J Byrne
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
| | - P Weigold
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
| | - S Behrens
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
| | - A Kappler
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
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Insights from the metagenome of an acid salt lake: the role of biology in an extreme depositional environment. PLoS One 2015; 10:e0122869. [PMID: 25923206 PMCID: PMC4414474 DOI: 10.1371/journal.pone.0122869] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 02/24/2015] [Indexed: 12/31/2022] Open
Abstract
The extremely acidic brine lakes of the Yilgarn Craton of Western Australia are home to some of the most biologically challenging waters on Earth. In this study, we employed metagenomic shotgun sequencing to generate a microbial profile of the depositional environment associated with the sulfur-rich sediments of one such lake. Of the 1.5 M high-quality reads generated, 0.25 M were mapped to protein features, which in turn provide new insights into the metabolic function of this community. In particular, 45 diverse genes associated with sulfur metabolism were identified, the majority of which were linked to either the conversion of sulfate to adenylylsulfate and the subsequent production of sulfide from sulfite or the oxidation of sulfide, elemental sulfur, and thiosulfate via the sulfur oxidation (Sox) system. This is the first metagenomic study of an acidic, hypersaline depositional environment, and we present evidence for a surprisingly high level of microbial diversity. Our findings also illuminate the possibility that we may be meaningfully underestimating the effects of biology on the chemistry of these sulfur-rich sediments, thereby influencing our understanding of past geobiological conditions that may have been present on Earth as well as early Mars.
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Oren A. Halophilic archaea on Earth and in space: growth and survival under extreme conditions. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2014; 372:rsta.2014.0194. [PMID: 25368347 DOI: 10.1098/rsta.2014.0194] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Salts are abundant on Mars, and any liquid water that is present or may have been present on the planet is expected to be hypersaline. Halophilic archaea (family Halobacteriaceae) are the microorganisms best adapted to life at extremes of salinity on Earth. This paper reviews the properties of the Halobacteriaceae that may make the group good candidates for life also on Mars. Many species resist high UV and gamma radiation levels; one species has survived exposure to vacuum and radiation during a space flight; and there is at least one psychrotolerant species. Halophilic archaea may survive for millions of years within brine inclusions in salt crystals. Many species have different modes of anaerobic metabolism, and some can use light as an energy source using the light-driven proton pump bacteriorhodopsin. They are also highly tolerant to perchlorate, recently shown to be present in Martian soils, and some species can even use perchlorate as an electron acceptor to support anaerobic growth. The presence of characteristic carotenoid pigments (α-bacterioruberin and derivatives) makes the Halobacteriaceae easy to identify by Raman spectroscopy. Thus, if present on Mars, such organisms may be detected by Raman instrumentation planned to explore Mars during the upcoming ExoMars mission.
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Affiliation(s)
- Aharon Oren
- Department of Plant and Environmental Sciences, The Alexander Silverman Institute of Life Sciences, The Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel
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28
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Stevenson A, Burkhardt J, Cockell CS, Cray JA, Dijksterhuis J, Fox-Powell M, Kee TP, Kminek G, McGenity TJ, Timmis KN, Timson DJ, Voytek MA, Westall F, Yakimov MM, Hallsworth JE. Multiplication of microbes below 0.690 water activity: implications for terrestrial and extraterrestrial life. Environ Microbiol 2014; 17:257-77. [DOI: 10.1111/1462-2920.12598] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 08/08/2014] [Accepted: 08/14/2014] [Indexed: 01/25/2023]
Affiliation(s)
- Andrew Stevenson
- Institute for Global Food Security; School of Biological Sciences; MBC; Queen's University Belfast; Belfast BT9 7BL Northern Ireland
| | - Jürgen Burkhardt
- Plant Nutrition Group; Institute of Crop Science and Resource Conservation; University of Bonn; Karlrobert-Kreiten-Str. 13 D-53115 Bonn Germany
| | - Charles S. Cockell
- UK Centre for Astrobiology; School of Physics and Astronomy; University of Edinburgh; Edinburgh EH9 3JZ UK
| | - Jonathan A. Cray
- Institute for Global Food Security; School of Biological Sciences; MBC; Queen's University Belfast; Belfast BT9 7BL Northern Ireland
| | - Jan Dijksterhuis
- CBS Fungal Biodiversity Centre; Uppsalalaan 8 CT 3584 Utrecht The Netherlands
| | - Mark Fox-Powell
- UK Centre for Astrobiology; School of Physics and Astronomy; University of Edinburgh; Edinburgh EH9 3JZ UK
| | - Terence P. Kee
- School of Chemistry; University of Leeds; Leeds LS2 9JT West Yorkshire UK
| | | | - Terry J. McGenity
- School of Biological Sciences; University of Essex; Colchester CO4 3SQ Essex UK
| | - Kenneth N. Timmis
- Institute of Microbiology; Technical University Braunschweig; Spielmannstrasse 7 D-38106 Braunschweig Germany
| | - David J. Timson
- Institute for Global Food Security; School of Biological Sciences; MBC; Queen's University Belfast; Belfast BT9 7BL Northern Ireland
| | | | - Frances Westall
- Centre de Biophysique Moléculaire; CNRS; Rue Charles Sadron; Centre de Recherches sur les Matériaux à Haute Température; 1D, avenue de la recherché scientifique 45071 Orléans Cedex 2 France
| | | | - John E. Hallsworth
- Institute for Global Food Security; School of Biological Sciences; MBC; Queen's University Belfast; Belfast BT9 7BL Northern Ireland
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Moran-Reyna A, Coker JA. The effects of extremes of pH on the growth and transcriptomic profiles of three haloarchaea. F1000Res 2014; 3:168. [PMID: 25285207 PMCID: PMC4176423 DOI: 10.12688/f1000research.4789.2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/26/2014] [Indexed: 12/03/2022] Open
Abstract
The halophilic archaea (haloarchaea) live in saline environments, which are found across the globe. In addition to salinity, these niches can be quite dynamic and experience extreme conditions such as low oxygen content, radiation (gamma and UV), pH and temperature. However, of all the naturally occurring stresses faced by the haloarchaea, only one, pH, has not been previously investigated in regard to the changes induced in the transcriptome. Therefore, we endeavored to determine the responses in three haloarchaea:
Halorubrum lacusprofundi (Hla),
Haloferax volcanii (Hvo), and
Halobacterium sp. NRC-1 (NRC-1) to growth under acidic and alkaline pH. Our observations showed that the transcriptomes of Hvo and NRC-1 regulated stress, motility, and ABC transporters in a similar manner, which is in line with previous reports from other prokaryotes when grown in an acidic environment. However, the pattern for Hla was more species specific. For alkaline stress, all three haloarchaea responded in a manner similar to well-studied archaea and bacteria showing the haloarchaeal response was general to prokaryotes. Additionally, we performed an analysis on the changes in the transcriptomes of the three haloarchaea when shifting from one pH extreme to the other. The results showed that the transcriptomes of all three haloarchaea respond more similarly when moving from alkaline to acidic conditions compared to a shift in the opposite direction. Interestingly, our studies also showed that individual genes of multiple paralogous gene families (
tbp,
tfb,
orc/
cdc6, etc.) found in the haloarchaea were regulated under specific stresses thereby providing evidence that they modulate the response to various environmental stresses. The studies described here are the first to catalog the changes in the haloarchaeal transcriptomes under growth in extreme pH and help us understand how life is able to thrive under all conditions present on Earth and, if present, on extraterrestrial bodies as well.
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Affiliation(s)
- Aida Moran-Reyna
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL, 35294-1170, USA
| | - James A Coker
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL, 35294-1170, USA ; The Graduate School, University of Maryland, University College, Largo, MD, 20774, USA
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Baxter BK, Gunde-Cimerman N, Oren A. Salty sisters: The women of halophiles. Front Microbiol 2014; 5:192. [PMID: 24926287 PMCID: PMC4045239 DOI: 10.3389/fmicb.2014.00192] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 04/10/2014] [Indexed: 01/02/2023] Open
Abstract
A history of halophile research reveals the commitment of scientists to uncovering the secrets of the limits of life, in particular life in high salt concentration and under extreme osmotic pressure. During the last 40 years, halophile scientists have indeed made important contributions to extremophile research, and prior international halophiles congresses have documented both the historical and the current work. During this period of salty discoveries, female scientists, in general, have grown in number worldwide. But those who worked in the field when there were small numbers of women sometimes saw their important contributions overshadowed by their male counterparts. Recent studies suggest that modern female scientists experience gender bias in matters such as conference invitations and even representation among full professors. In the field of halophilic microbiology, what is the impact of gender bias? How has the participation of women changed over time? What do women uniquely contribute to this field? What are factors that impact current female scientists to a greater degree? This essay emphasizes the “her story” (not “history”) of halophile discovery.
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Affiliation(s)
- Bonnie K Baxter
- Great Salt Lake Institute, Westminster College Salt Lake City, UT, USA
| | - Nina Gunde-Cimerman
- Molecular Genetics and Microbiology, University of Ljubljana Ljubljana, Slovenia ; Centre of Excellence for Integrated Approaches in Chemistry and Biology of Proteins Ljubljana, Slovenia
| | - Aharon Oren
- Department of Plant and Environmental Sciences, The Institute of Life Sciences, The Edmond J. Safra Campus, The Hebrew University of Jerusalem Givat Ram, Israel
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Conner AJ, Benison KC. Acidophilic halophilic microorganisms in fluid inclusions in halite from Lake Magic, Western Australia. ASTROBIOLOGY 2013; 13:850-60. [PMID: 23971647 PMCID: PMC3778947 DOI: 10.1089/ast.2012.0956] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Lake Magic is one of the most extreme of hundreds of ephemeral acid-saline lakes in southern Western Australia. It has pH as low as 1.7, salinity as high as 32% total dissolved solids, temperatures ranging from 0°C to 50°C, and an unusually complex aqueous composition. Optical petrography, UV-vis petrography, and laser Raman spectrometry were used to detect microorganisms and organic compounds within primary fluid inclusions in modern bedded halite from Lake Magic. Rare prokaryotes appear as 1-3 μm, bright cocci that fluoresce green with UV-vis illumination. Dimpled, 5-7 μm yellow spherules that fluoresce blue with UV-vis illumination are interpreted as Dunaliella algae. Yellow-orange beta-carotene crystals, globules, and coatings are characterized by orange-red fluorescence and three distinct Raman peaks. Because acid saline lakes are good Mars analogues, the documentation of prokaryotes, eukaryotes, and organic compounds preserved in the halite here has implications for the search for life on Mars. Missions to Mars should incorporate such in situ optical and chemical examination of martian evaporites for possible microorganisms and/or organic compounds in fluid inclusions.
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Affiliation(s)
- Amber J. Conner
- Department of Earth and Atmospheric Sciences, Central Michigan University, Mt. Pleasant, Michigan
| | - Kathleen C. Benison
- Department of Geology and Geography, West Virginia University, Morgantown, West Virginia
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Westall F. Microbial Scale Habitability on Mars. HABITABILITY OF OTHER PLANETS AND SATELLITES 2013. [DOI: 10.1007/978-94-007-6546-7_11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Carneiro CEA, de Santana H, Casado C, Coronas J, Zaia DAM. Adsorption of amino acids (ALA, CYS, HIS, MET) on zeolites: fourier transform infrared and Raman spectroscopy investigations. ASTROBIOLOGY 2011; 11:409-418. [PMID: 21671763 DOI: 10.1089/ast.2010.0521] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Minerals adsorb more amino acids with charged R-groups than amino acids with uncharged R-groups. Thus, the peptides that form from the condensation of amino acids on the surface of minerals should be composed of amino acid residues that are more charged than uncharged. However, most of the amino acids (74%) in today's proteins have an uncharged R-group. One mechanism with which to solve this paradox is the use of organophilic minerals such as zeolites. Over the range of pH (pH 2.66-4.50) used in these experiments, the R-group of histidine (His) is positively charged and neutral for alanine (Ala), cysteine (Cys), and methionine (Met). In acidic hydrothermal environments, the pH could be even lower than those used in this study. For the pH range studied, the zeolites were negatively charged, and the overall charge of all amino acids was positive. The conditions used here approximate those of prebiotic Earth. The most important finding of this work is that the relative concentrations of each amino acid (X=His, Met, Cys) to alanine (X/Ala) are close to 1.00. This is an important result with regard to prebiotic chemistry because it could be a solution for the paradox stated above. Pore size did not affect the adsorption of Cys and Met on zeolites, and the Si/Al ratio did not affect the adsorption of Cys, His, and Met. ZSM-5 could be used for the purification of Cys from other amino acids (Student-Newman-Keuls test, p<0.05), and mordenite could be used for separation of amino acids from each other (Student-Newman-Keuls test, p<0.05). As shown by Fourier transform infrared (FT-IR) spectra, Ala interacts with zeolites through the [Formula: see text] group, and methionine-zeolite interactions involve the COO, [Formula: see text], and CH(3) groups. FT-IR spectra show that the interaction between the zeolites and His is weak. Cys showed higher adsorption on all zeolites; however, the hydrophobic Van der Waals interaction between zeolites and Cys is too weak to produce any structural changes in the Cys groups (amine, carboxylic, sulfhydryl, etc.); thus, the FT-IR and Raman spectra are the same as those of solid Cys.
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Wray JJ, Milliken RE, Dundas CM, Swayze GA, Andrews-Hanna JC, Baldridge AM, Chojnacki M, Bishop JL, Ehlmann BL, Murchie SL, Clark RN, Seelos FP, Tornabene LL, Squyres SW. Columbus crater and other possible groundwater-fed paleolakes of Terra Sirenum, Mars. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010je003694] [Citation(s) in RCA: 121] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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35
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Evidence for the Biogenic Origin of Sepiolite. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/b978-0-444-53607-5.00009-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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