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Harmon RS, Khashchevskaya D, Morency M, Owen LA, Jennings M, Knott JR, Dortch JM. Analysis of Rock Varnish from the Mojave Desert by Handheld Laser-Induced Breakdown Spectroscopy. Molecules 2021; 26:molecules26175200. [PMID: 34500634 PMCID: PMC8433696 DOI: 10.3390/molecules26175200] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 08/19/2021] [Accepted: 08/24/2021] [Indexed: 11/16/2022] Open
Abstract
Laser-induced breakdown spectroscopy (LIBS) is a form of optical emission spectroscopy that can be used for the rapid analysis of geological materials in the field under ambient environmental conditions. We describe here the innovative use of handheld LIBS for the in situ analysis of rock varnish. This thinly laminated and compositionally complex veneer forms slowly over time on rock surfaces in dryland regions and is particularly abundant across the Mojave Desert climatic region of east-central California (USA). Following the depth profiling examination of a varnished clast from colluvial gravel in Death Valley in the laboratory, our in situ analysis of rock varnish and visually similar coatings on rock surfaces was undertaken in the Owens and Deep Spring valleys in two contexts, element detection/identification and microchemical mapping. Emission peaks were recognized in the LIBS spectra for the nine elements most abundant in rock varnish-Mn, Fe, Si, Al, Na, Mg, K, Ca and Ba, as well as for H, Li, C, O, Ti, V, Sr and Rb. Focused follow-up laboratory and field studies will help understand rock varnish formation and its utility for weathering and chronological studies.
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Affiliation(s)
- Russell S. Harmon
- Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695, USA; (D.K.); (M.M.); (L.A.O.)
- Correspondence: ; Tel.: +1-919-588-0613
| | - Daria Khashchevskaya
- Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695, USA; (D.K.); (M.M.); (L.A.O.)
| | - Michelle Morency
- Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695, USA; (D.K.); (M.M.); (L.A.O.)
| | - Lewis A. Owen
- Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695, USA; (D.K.); (M.M.); (L.A.O.)
| | | | - Jeffrey R. Knott
- Department of Geological Sciences, California State University, Fullerton, Fullerton, CA 92831, USA;
| | - Jason M. Dortch
- Kentucky Geological Survey, University of Kentucky, Lexington, KY 40508, USA;
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2
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Shining light on photosynthetic microbes and manganese-enriched rock varnish. Proc Natl Acad Sci U S A 2021; 118:2109436118. [PMID: 34183441 DOI: 10.1073/pnas.2109436118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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3
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Abstract
Rock varnish is a prominent feature of desert landscapes and the canvas for many prehistoric petroglyphs. How it forms—and, in particular, the basis for its extremely high manganese content—has been an enduring mystery. The work presented here establishes a biological mechanism for this manganese enrichment, underpinned by an apparent antioxidant strategy that enables microbes to survive in the harsh environments where varnish forms. The understanding that varnish is the residue of life using manganese to thrive in the desert illustrates that, even in extremely stark environments, the imprint of life is omnipresent on the landscape. Desert varnish is a dark rock coating that forms in arid environments worldwide. It is highly and selectively enriched in manganese, the mechanism for which has been a long-standing geological mystery. We collected varnish samples from diverse sites across the western United States, examined them in petrographic thin section using microscale chemical imaging techniques, and investigated the associated microbial communities using 16S amplicon and shotgun metagenomic DNA sequencing. Our analyses described a material governed by sunlight, water, and manganese redox cycling that hosts an unusually aerobic microbial ecosystem characterized by a remarkable abundance of photosynthetic Cyanobacteria in the genus Chroococcidiopsis as the major autotrophic constituent. We then showed that diverse Cyanobacteria, including the relevant Chroococcidiopsis taxon, accumulate extraordinary amounts of intracellular manganese—over two orders of magnitude higher manganese content than other cells. The speciation of this manganese determined by advanced paramagnetic resonance techniques suggested that the Cyanobacteria use it as a catalytic antioxidant—a valuable adaptation for coping with the substantial oxidative stress present in this environment. Taken together, these results indicated that the manganese enrichment in varnish is related to its specific uptake and use by likely founding members of varnish microbial communities.
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4
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Genderjahn S, Lewin S, Horn F, Schleicher AM, Mangelsdorf K, Wagner D. Living Lithic and Sublithic Bacterial Communities in Namibian Drylands. Microorganisms 2021; 9:235. [PMID: 33498742 PMCID: PMC7911874 DOI: 10.3390/microorganisms9020235] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 01/17/2021] [Accepted: 01/20/2021] [Indexed: 12/26/2022] Open
Abstract
Dryland xeric conditions exert a deterministic effect on microbial communities, forcing life into refuge niches. Deposited rocks can form a lithic niche for microorganisms in desert regions. Mineral weathering is a key process in soil formation and the importance of microbial-driven mineral weathering for nutrient extraction is increasingly accepted. Advances in geobiology provide insight into the interactions between microorganisms and minerals that play an important role in weathering processes. In this study, we present the examination of the microbial diversity in dryland rocks from the Tsauchab River banks in Namibia. We paired culture-independent 16S rRNA gene amplicon sequencing with culture-dependent (isolation of bacteria) techniques to assess the community structure and diversity patterns. Bacteria isolated from dryland rocks are typical of xeric environments and are described as being involved in rock weathering processes. For the first time, we extracted extra- and intracellular DNA from rocks to enhance our understanding of potentially rock-weathering microorganisms. We compared the microbial community structure in different rock types (limestone, quartz-rich sandstone and quartz-rich shale) with adjacent soils below the rocks. Our results indicate differences in the living lithic and sublithic microbial communities.
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Affiliation(s)
- Steffi Genderjahn
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany; (S.L.); (F.H.); (D.W.)
| | - Simon Lewin
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany; (S.L.); (F.H.); (D.W.)
| | - Fabian Horn
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany; (S.L.); (F.H.); (D.W.)
| | - Anja M. Schleicher
- GFZ German Research Centre for Geosciences, Section Organic Geochemistry, Telegrafenberg, 14473 Potsdam, Germany;
| | - Kai Mangelsdorf
- GFZ German Research Centre for Geosciences, Section Anorganic Chemistry, Telegrafenberg, 14473 Potsdam, Germany;
| | - Dirk Wagner
- GFZ German Research Centre for Geosciences, Section Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany; (S.L.); (F.H.); (D.W.)
- Institute of Geosciences, University of Potsdam, 14476 Potsdam, Germany
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5
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Negi A, Sarethy IP. Microbial Biodeterioration of Cultural Heritage: Events, Colonization, and Analyses. MICROBIAL ECOLOGY 2019; 78:1014-1029. [PMID: 31025063 DOI: 10.1007/s00248-019-01366-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 03/18/2019] [Indexed: 06/09/2023]
Abstract
Geochemical cycles result in the chemical, physical, and mineralogical modification of rocks, eventually leading to formation of soil. However, when the stones and rocks are a part of historic buildings and monuments, the effects are deleterious. In addition, microorganisms also colonize these monuments over a period of time, resulting in formation of biofilms; their metabolites lead to physical weakening and discoloration of stone eventually. This process, known as biodeterioration, leads to a significant loss of cultural heritage. For formulating effective conservation strategies to prevent biodeterioration and restore monuments, it is important to know which microorganisms are colonizing the substrate and the different energy sources they consume to sustain themselves. With this view in scope, this review focuses on studies that have attempted to understand the process of biodeterioration, the mechanisms by which they colonize and affect the monuments, the techniques used for assessment of biodeterioration, and conservation strategies that aim to preserve the original integrity of the monuments. This review also includes the "omics" technologies that have started playing a large role in elucidating the nature of microorganisms, and how they can play a role in hastening the formulation of effective conservation strategies.
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Affiliation(s)
- Abhishek Negi
- Department of Biotechnology, Jaypee Institute of Information Technology, A-10, Sec 62, Noida, 201309, India
| | - Indira P Sarethy
- Department of Biotechnology, Jaypee Institute of Information Technology, A-10, Sec 62, Noida, 201309, India.
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6
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Seasonal diversity of the bacterial communities associated with petroglyphs sites from the Negev Desert, Israel. ANN MICROBIOL 2019. [DOI: 10.1007/s13213-019-01509-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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7
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Ren G, Yan Y, Nie Y, Lu A, Wu X, Li Y, Wang C, Ding H. Natural Extracellular Electron Transfer Between Semiconducting Minerals and Electroactive Bacterial Communities Occurred on the Rock Varnish. Front Microbiol 2019; 10:293. [PMID: 30886603 PMCID: PMC6410676 DOI: 10.3389/fmicb.2019.00293] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 02/04/2019] [Indexed: 11/13/2022] Open
Abstract
Rock varnish is a thin coating enriched with manganese (Mn) and iron (Fe) oxides. The mineral composition and formation of rock varnish elicit considerable attention from geologists and microbiologists. However, limited research has been devoted to the semiconducting properties of these Fe/Mn oxides in varnish and relatively little attention is paid to the mineral-microbe interaction under sunlight. In this study, the mineral composition and the bacterial communities on varnish from the Gobi Desert in Xinjiang, China were analyzed. Results of principal components analysis and t-test indicated that more electroactive genera such as Acinetobacter, Staphylococcus, Dietzia, and Pseudomonas gathered on varnish bacterial communities than on substrate rock and surrounding soils. We then explored the culture of varnish, substrate and soil samples in media and the extracellular electron transfer (EET) between bacterial communities and mineral electrodes under light/dark conditions for the first time. Orthogonal electrochemical experiments demonstrated that the most remarkable photocurrent density of 6.1 ± 0.4 μA/cm2 was observed between varnish electrode and varnish microflora. Finally, based on Raman and 16S rRNA gene-sequencing results, coculture system of birnessite and Pseudomonas (the major Mn oxide and a common electroactive bacterium in varnish) was established to study underlying mechanism. A steadily growing photocurrent (205 μA at 100 h) under light was observed with a stable birnessite after 110 h. However, only 47 μA was generated in the dark control and birnessite was reduced to Mn2+ in 13 h, suggesting that birnessite helped deliver electrons instead of serving as an electron acceptor under light. Our study demonstrated that electroactive bacterial communities were positively correlated with Fe/Mn semiconducting minerals in varnish, and diversified EET process occurred on varnish under sunlight. Overall, these phenomena may influence bacterial-community structure in natural environments over time.
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Affiliation(s)
- Guiping Ren
- The Key Laboratory of Orogenic Belts and Crustal Evolution, Beijing Key Laboratory of Mineral Environmental Function, School of Earth and Space Sciences, Peking University, Beijing, China
| | - Yingchun Yan
- College of Engineering, Peking University, Beijing, China
| | - Yong Nie
- College of Engineering, Peking University, Beijing, China
| | - Anhuai Lu
- The Key Laboratory of Orogenic Belts and Crustal Evolution, Beijing Key Laboratory of Mineral Environmental Function, School of Earth and Space Sciences, Peking University, Beijing, China
| | - Xiaolei Wu
- College of Engineering, Peking University, Beijing, China
| | - Yan Li
- The Key Laboratory of Orogenic Belts and Crustal Evolution, Beijing Key Laboratory of Mineral Environmental Function, School of Earth and Space Sciences, Peking University, Beijing, China
| | - Changqiu Wang
- The Key Laboratory of Orogenic Belts and Crustal Evolution, Beijing Key Laboratory of Mineral Environmental Function, School of Earth and Space Sciences, Peking University, Beijing, China
| | - Hongrui Ding
- The Key Laboratory of Orogenic Belts and Crustal Evolution, Beijing Key Laboratory of Mineral Environmental Function, School of Earth and Space Sciences, Peking University, Beijing, China
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8
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Warren-Rhodes KA, Lee KC, Archer SDJ, Cabrol N, Ng-Boyle L, Wettergreen D, Zacny K, Pointing SB. Subsurface Microbial Habitats in an Extreme Desert Mars-Analog Environment. Front Microbiol 2019; 10:69. [PMID: 30873126 PMCID: PMC6403490 DOI: 10.3389/fmicb.2019.00069] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 01/15/2019] [Indexed: 02/03/2023] Open
Abstract
Sediments in the hyper-arid core of the Atacama Desert are a terrestrial analog to Mars regolith. Understanding the distribution and drivers of microbial life in the sediment may give critical clues on how to search for biosignatures on Mars. Here, we identify the spatial distribution of highly specialized bacterial communities in previously unexplored depth horizons of subsurface sediments to a depth of 800 mm. We deployed an autonomous rover in a mission-relevant Martian drilling scenario with manual sample validation. Subsurface communities were delineated by depth related to sediment moisture. Geochemical analysis indicated soluble salts and minerology that influenced water bio-availability, particularly in deeper sediments. Colonization was also patchy and uncolonized sediment was associated with indicators of extreme osmotic challenge. The study identifies linkage between biocomplexity, moisture and geochemistry in Mars-like sediments at the limit of habitability and demonstrates feasibility of the rover-mounted drill for future Mars sample recovery.
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Affiliation(s)
- Kimberley A Warren-Rhodes
- NASA Ames Research Center, Mountain View, CA, United States.,The SETI Institute, Mountain View, CA, United States
| | - Kevin C Lee
- School of Sciences, Auckland University of Technology, Auckland, New Zealand
| | - Stephen D J Archer
- School of Sciences, Auckland University of Technology, Auckland, New Zealand
| | - Nathalie Cabrol
- NASA Ames Research Center, Mountain View, CA, United States.,The SETI Institute, Mountain View, CA, United States
| | - Linda Ng-Boyle
- College of Engineering, University of Washington, Seattle, WA, United States
| | - David Wettergreen
- Institute of Robotics, Carnegie Mellon University, Pittsburgh, PA, United States
| | - Kris Zacny
- Honeybee Robotics Spacecraft Mechanisms Corp., Pasadena, CA, United States
| | - Stephen B Pointing
- Yale-NUS College, National University of Singapore, Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore
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9
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Lang-Yona N, Maier S, Macholdt DS, Müller-Germann I, Yordanova P, Rodriguez-Caballero E, Jochum KP, Al-Amri A, Andreae MO, Fröhlich-Nowoisky J, Weber B. Insights into microbial involvement in desert varnish formation retrieved from metagenomic analysis. ENVIRONMENTAL MICROBIOLOGY REPORTS 2018; 10:264-271. [PMID: 29488349 DOI: 10.1111/1758-2229.12634] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 02/19/2018] [Indexed: 06/08/2023]
Abstract
Desert varnishes are dark rock coatings observed in arid environments and might resemble Mn-rich coatings found on Martian rocks. Their formation mechanism is not fully understood and the possible microbial involvement is under debate. In this study, we applied DNA metagenomic Shotgun sequencing of varnish and surrounding soil to evaluate the composition of the microbial community and its potential metabolic function. We found that the α diversity was lower in varnish compared to soil samples (p value < 0.05), suggesting distinct populations with significantly higher abundance of Actinobacteria, Proteobacteria and Cyanobacteria within the varnish. Additionally, we observed increased levels of transition metal metabolic processes in varnish compared to soil samples. Nevertheless, potentially relevant enzymes for varnish formation were detected at low to insignificant levels in both niches, indicating no current direct microbial involvement in Mn oxidation. This finding is supported by quantitative genomic analysis, elemental analysis, fluorescence imaging and scanning transmission X-ray microscopy. We thus conclude that the distinct microbial communities detected in desert varnish originate from settled Aeolian microbes, which colonized this nutrient-enriched niche, and discuss possible indirect contributions of microorganisms to the formation of desert varnish.
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Affiliation(s)
- Naama Lang-Yona
- Multiphase Chemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Stefanie Maier
- Multiphase Chemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Dorothea S Macholdt
- Biogeochemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
- Climate Geochemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Isabell Müller-Germann
- Multiphase Chemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Petya Yordanova
- Multiphase Chemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Emilio Rodriguez-Caballero
- Multiphase Chemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Klaus P Jochum
- Climate Geochemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Abdullah Al-Amri
- Geology and Geophysics Department, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia
| | - Meinrat O Andreae
- Biogeochemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
- Geology and Geophysics Department, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia
| | - Janine Fröhlich-Nowoisky
- Multiphase Chemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Bettina Weber
- Multiphase Chemistry Department, Hahn-Meitner-Weg 1, Max Planck Institute for Chemistry, 55128 Mainz, Germany
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10
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Santibáñez PA, Maselli OJ, Greenwood MC, Grieman MM, Saltzman ES, McConnell JR, Priscu JC. Prokaryotes in the WAIS Divide ice core reflect source and transport changes between Last Glacial Maximum and the early Holocene. GLOBAL CHANGE BIOLOGY 2018; 24:2182-2197. [PMID: 29322639 DOI: 10.1111/gcb.14042] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 11/25/2017] [Indexed: 06/07/2023]
Abstract
We present the first long-term, highly resolved prokaryotic cell concentration record obtained from a polar ice core. This record, obtained from the West Antarctic Ice Sheet (WAIS) Divide (WD) ice core, spanned from the Last Glacial Maximum (LGM) to the early Holocene (EH) and showed distinct fluctuations in prokaryotic cell concentration coincident with major climatic states. The time series also revealed a ~1,500-year periodicity with greater amplitude during the Last Deglaciation (LDG). Higher prokaryotic cell concentration and lower variability occurred during the LGM and EH than during the LDG. A sevenfold decrease in prokaryotic cell concentration coincided with the LGM/LDG transition and the global 19 ka meltwater pulse. Statistical models revealed significant relationships between the prokaryotic cell record and tracers of both marine (sea-salt sodium [ssNa]) and burning emissions (black carbon [BC]). Collectively, these models, together with visual observations and methanosulfidic acid (MSA) measurements, indicated that the temporal variability in concentration of airborne prokaryotic cells reflected changes in marine/sea-ice regional environments of the WAIS. Our data revealed that variations in source and transport were the most likely processes producing the significant temporal variations in WD prokaryotic cell concentrations. This record provided strong evidence that airborne prokaryotic cell deposition differed during the LGM, LDG, and EH, and that these changes in cell densities could be explained by different environmental conditions during each of these climatic periods. Our observations provide the first ice-core time series evidence for a prokaryotic response to long-term climatic and environmental processes.
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Affiliation(s)
- Pamela A Santibáñez
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
- Departamento Científico, Instituto Antártico Chileno (INACH), Punta Arenas, Chile
| | - Olivia J Maselli
- Desert Research Institute, Nevada System of Higher Education, Reno, NV, USA
| | - Mark C Greenwood
- Department of Mathematical Sciences, Montana State University, Bozeman, MT, USA
| | - Mackenzie M Grieman
- Department of Earth System Science, University of California, Irvine, CA, USA
| | - Eric S Saltzman
- Department of Earth System Science, University of California, Irvine, CA, USA
| | - Joseph R McConnell
- Desert Research Institute, Nevada System of Higher Education, Reno, NV, USA
| | - John C Priscu
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
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11
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Polgári M, Bérczi S, Horiuchi K, Matsuzaki H, Kovács T, Józsa S, Bendő Z, Fintor K, Fekete J, Homonnay Z, Kuzmann E, Gucsik A, Gyollai I, Kovács J, Dódony I. Characterization and 10Be content of iron carbonate concretions for genetic aspects - Weathering, desert varnish or burning: Rim effects in iron carbonate concretions. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2017; 173:58-69. [PMID: 28011110 DOI: 10.1016/j.jenvrad.2016.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 11/06/2016] [Accepted: 11/07/2016] [Indexed: 06/06/2023]
Abstract
The research investigated three iron carbonate (siderite) sedimentary concretions from Nagykovácsi, Úri and Délegyháza, Hungary. To identify possible source rocks and effects of the glaze-like exposed surface of the concretions, we carried on comparative petrological, mineralogical, geochemical and isotopic studies. The samples were microbially mediated siderite concretions with embedded metamorphous and igneous mineral clasts, and had specific rim belts characterized by semi-concentric outer Fe-oxide layers, fluffy pyrite-rich outer belts and siderite inner parts. We investigated the cross section of the Fe-carbonate concretions by independent methodologies in order to identify their rim effects. Their surficial oxide layers showed evidence of degassing of the exposed surface caused most probably by elevated temperatures. The inner rim pyrite belt in the concretions excluded the possibility of a prolonged wet surface environment. Microtextural and mineralogical features did not support desert varnish formation. 10Be nuclide values of the Nagykovácsi and Uri concretions were far above the level of terrestrial in-situ cosmogenic nuclides, but they were consistent with the lowest levels for meteorites. Though the data were not conclusive to confirm any kind of known origin, they are contradictary, and open possibilities for a scenario of terrestrial meteorite origin.
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Affiliation(s)
- Márta Polgári
- Research Center for Astronomy and Geosciences, Geobiomineralization and Astrobiological Research Group, Institute for Geology and Geochemistry, Hungarian Academy of Sciences, 1112, Budapest, Budaörsi út. 45, Hungary; Eszterházy Károly University, Dept. of Physical Geography and Geoinformatics, Leányka str. 6, 3300, Eger, Hungary.
| | - Szaniszló Bérczi
- Eötvös University, Faculty of Science, Dept. of Materials Physics, Cosmic Materials Space Res. Group, 1117, Budapest, Pázmány P. s. 1/a, Hungary.
| | - Kazuho Horiuchi
- Graduate School of Science and Technology, Hirosaki University, 3, Bunkyo-chou, Hirosaki, Aomori, 036-8561, Japan.
| | - Hiroyuki Matsuzaki
- Micro Analysis Laboratory, Tandem Accelerator (MALT), The University Museum, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan.
| | - Tibor Kovács
- Institute of Radiochemistry and Radioecology, University of Pannonia, Egyetem Str. 10, Veszprém, H-8200, Hungary.
| | - Sándor Józsa
- Eötvös University, Dept. Petrology and Geochemistry, 1117, Budapest, Pázmány P. s. 1/c, Hungary
| | - Zsolt Bendő
- Eötvös University, Dept. Petrology and Geochemistry, 1117, Budapest, Pázmány P. s. 1/c, Hungary
| | - Krisztián Fintor
- Szeged University, Department of Mineralogy, Geochemistry and Petrology, Egyetem str. 2-6, 6702, Szeged, Hungary.
| | - József Fekete
- Research Center for Astronomy and Geosciences, Geobiomineralization and Astrobiological Research Group, Institute for Geology and Geochemistry, Hungarian Academy of Sciences, 1112, Budapest, Budaörsi út. 45, Hungary
| | - Zoltán Homonnay
- Eötvös University, Inst. of Chemistry, 1117, Budapest, Pázmány P. s. 1/a, Hungary
| | - Ernő Kuzmann
- Eötvös University, Inst. of Chemistry, 1117, Budapest, Pázmány P. s. 1/a, Hungary
| | - Arnold Gucsik
- University of Johannesburg, Department of Geology, 2600, Auckland Park, Johannesburg, South Africa
| | - Ildikó Gyollai
- Research Center for Astronomy and Geosciences, Geobiomineralization and Astrobiological Research Group, Institute for Geology and Geochemistry, Hungarian Academy of Sciences, 1112, Budapest, Budaörsi út. 45, Hungary
| | - János Kovács
- Department of Geology & Meteorology, Environmental Analytical & Geoanalytical Research Group, Szentágothai Research Centre, University of Pécs, 7624, Pécs, Ifjúság útja 6 and 20, Hungary
| | - István Dódony
- Eötvös University, Dept. Mineralogy, H-1117, Budapest, Pázmány P. s. 1/c, Hungary
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12
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Marcus DN, Pinto A, Anantharaman K, Ruberg SA, Kramer EL, Raskin L, Dick GJ. Diverse manganese(II)-oxidizing bacteria are prevalent in drinking water systems. ENVIRONMENTAL MICROBIOLOGY REPORTS 2017; 9:120-128. [PMID: 27935222 DOI: 10.1111/1758-2229.12508] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 11/22/2016] [Indexed: 06/06/2023]
Abstract
Manganese (Mn) oxides are highly reactive minerals that influence the speciation, mobility, bioavailability and toxicity of a wide variety of organic and inorganic compounds. Although Mn(II)-oxidizing bacteria are known to catalyze the formation of Mn oxides, little is known about the organisms responsible for Mn oxidation in situ, especially in engineered environments. Mn(II)-oxidizing bacteria are important in drinking water systems, including in biofiltration and water distribution systems. Here, we used cultivation dependent and independent approaches to investigate Mn(II)-oxidizing bacteria in drinking water sources, a treatment plant and associated distribution system. We isolated 29 strains of Mn(II)-oxidizing bacteria and found that highly similar 16S rRNA gene sequences were present in all culture-independent datasets and dominant in the studied drinking water treatment plant. These results highlight a potentially important role for Mn(II)-oxidizing bacteria in drinking water systems, where biogenic Mn oxides may affect water quality in terms of aesthetic appearance, speciation of metals and oxidation of organic and inorganic compounds. Deciphering the ecology of these organisms and the factors that regulate their Mn(II)-oxidizing activity could yield important insights into how microbial communities influence the quality of drinking water.
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Affiliation(s)
- Daniel N Marcus
- Department of Earth and Environmental Science, University of Michigan, Ann Arbor, MI, USA
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Ameet Pinto
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, USA
| | - Karthik Anantharaman
- Department of Earth and Environmental Science, University of Michigan, Ann Arbor, MI, USA
| | - Steven A Ruberg
- Great Lakes Environmental Research Laboratory, National Oceanic and Atmospheric Administration, Ann Arbor, MI, USA
| | - Eva L Kramer
- Department of Earth and Environmental Science, University of Michigan, Ann Arbor, MI, USA
| | - Lutgarde Raskin
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Gregory J Dick
- Department of Earth and Environmental Science, University of Michigan, Ann Arbor, MI, USA
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13
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A standardized approach for co-culturing dothidealean rock-inhabiting fungi and lichen photobionts in vitro. Symbiosis 2017. [DOI: 10.1007/s13199-017-0479-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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14
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15
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Esposito A, Ahmed E, Ciccazzo S, Sikorski J, Overmann J, Holmström SJM, Brusetti L. Comparison of Rock Varnish Bacterial Communities with Surrounding Non-Varnished Rock Surfaces: Taxon-Specific Analysis and Morphological Description. MICROBIAL ECOLOGY 2015; 70:741-750. [PMID: 25921518 DOI: 10.1007/s00248-015-0617-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/16/2015] [Indexed: 06/04/2023]
Abstract
Rock varnish is a thin layer of Fe and Mn oxyhydroxides with embedded clay minerals that contain an increased Mn/Fe ratio compared to that of the Earth's crust. Even if the study of rock varnish has important implications in several fields, the composition of epilithic bacterial communities and the distribution of taxa on varnish surfaces are still not wholly described. The aim of this study was (i) to identify the bacterial taxa which show the greatest variation between varnish and non-varnish environments, collected from the same rock, and (ii) to describe the morphology of epilithic communities through scanning electron microscopy (SEM). Triplicate samples of rock surfaces with varnish and triplicate samples without varnish were collected from five sites in Matsch Valley (South Tyrol, Italy). The V4 region of 16S rRNA gene was analyzed by Illumina sequencing. Fifty-five ubiquitous taxa have been examined to assess variation between varnish and non-varnish. Cyanobacteria, Chloroflexi, Proteobacteria along with minor taxa such as Solirubrobacterales, Conexibaxter, and Rhodopila showed significant variations of abundance, diversity, or both responding to the ecology (presence/absence of varnish). Other taxa, such as the genus Edaphobacter, showed a more marked spatial variation responding to the sampling site. SEM images showed a multitude of bacterial morphologies and structures involved in the process of attachment and creation of a suitable environment for growth. The features emerging from this analysis suggest that the highly oxidative Fe and Mn-rich varnish environment favors anoxigenic autotrophy and establishment of highly specialized bacteria.
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Affiliation(s)
- Alfonso Esposito
- Faculty of Science and Technology, Free University of Bozen-Bolzano, Piazza Università 1, I-39100, Bozen-Bolzano, Italy
| | - Engy Ahmed
- Department of Geological Sciences, Stockholm University, SE-10691, Stockholm, Sweden
| | - Sonia Ciccazzo
- Faculty of Science and Technology, Free University of Bozen-Bolzano, Piazza Università 1, I-39100, Bozen-Bolzano, Italy
| | - Johannes Sikorski
- Leibniz-Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Inhoffenstraße 7 B, D-38124, Braunschweig, Germany
| | - Jörg Overmann
- Leibniz-Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Inhoffenstraße 7 B, D-38124, Braunschweig, Germany
| | - Sara J M Holmström
- Department of Geological Sciences, Stockholm University, SE-10691, Stockholm, Sweden
| | - Lorenzo Brusetti
- Faculty of Science and Technology, Free University of Bozen-Bolzano, Piazza Università 1, I-39100, Bozen-Bolzano, Italy.
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16
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Rummel JD, Beaty DW, Jones MA, Bakermans C, Barlow NG, Boston PJ, Chevrier VF, Clark BC, de Vera JPP, Gough RV, Hallsworth JE, Head JW, Hipkin VJ, Kieft TL, McEwen AS, Mellon MT, Mikucki JA, Nicholson WL, Omelon CR, Peterson R, Roden EE, Sherwood Lollar B, Tanaka KL, Viola D, Wray JJ. A new analysis of Mars "Special Regions": findings of the second MEPAG Special Regions Science Analysis Group (SR-SAG2). ASTROBIOLOGY 2014; 14:887-968. [PMID: 25401393 DOI: 10.1089/ast.2014.1227] [Citation(s) in RCA: 148] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
A committee of the Mars Exploration Program Analysis Group (MEPAG) has reviewed and updated the description of Special Regions on Mars as places where terrestrial organisms might replicate (per the COSPAR Planetary Protection Policy). This review and update was conducted by an international team (SR-SAG2) drawn from both the biological science and Mars exploration communities, focused on understanding when and where Special Regions could occur. The study applied recently available data about martian environments and about terrestrial organisms, building on a previous analysis of Mars Special Regions (2006) undertaken by a similar team. Since then, a new body of highly relevant information has been generated from the Mars Reconnaissance Orbiter (launched in 2005) and Phoenix (2007) and data from Mars Express and the twin Mars Exploration Rovers (all 2003). Results have also been gleaned from the Mars Science Laboratory (launched in 2011). In addition to Mars data, there is a considerable body of new data regarding the known environmental limits to life on Earth-including the potential for terrestrial microbial life to survive and replicate under martian environmental conditions. The SR-SAG2 analysis has included an examination of new Mars models relevant to natural environmental variation in water activity and temperature; a review and reconsideration of the current parameters used to define Special Regions; and updated maps and descriptions of the martian environments recommended for treatment as "Uncertain" or "Special" as natural features or those potentially formed by the influence of future landed spacecraft. Significant changes in our knowledge of the capabilities of terrestrial organisms and the existence of possibly habitable martian environments have led to a new appreciation of where Mars Special Regions may be identified and protected. The SR-SAG also considered the impact of Special Regions on potential future human missions to Mars, both as locations of potential resources and as places that should not be inadvertently contaminated by human activity.
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Affiliation(s)
- John D Rummel
- 1 Department of Biology, East Carolina University , Greenville, North Carolina, USA
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17
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Ziolkowski LA, Wierzchos J, Davila AF, Slater GF. Radiocarbon evidence of active endolithic microbial communities in the hyperarid core of the Atacama Desert. ASTROBIOLOGY 2013; 13:607-16. [PMID: 23848470 PMCID: PMC3713447 DOI: 10.1089/ast.2012.0854] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The hyperarid core of the Atacama Desert is one of the driest and most inhospitable places on Earth, where life is most commonly found in the interior of rocks (i.e., endolithic habitats). Due to the extreme dryness, microbial activity in these habitats is expected to be low; however, the rate of carbon cycling within these microbial communities remains unknown. We address this issue by characterizing the isotopic composition ((13)C and (14)C) of phospholipid fatty acids (PLFA) and glycolipid fatty acids (GLFA) in colonized rocks from four different sites inside the hyperarid core. δ(13)C results suggest that autotrophy and/or quantitative conversion of organic matter to CO2 are the dominant processes occurring with the rock. Most Δ(14)C signatures of PLFA and GLFA were consistent with modern atmospheric CO2, indicating that endoliths are using atmospheric carbon as a primary carbon source and are also cycling carbon quickly. However, at one site the PLFA contained (14)C from atmospheric nuclear weapons testing that occurred during the 1950s and 1960s, indicating a decadal rate of carbon cycling. At the driest site (Yungay), based on the relative abundance and (14)C content of GLFA and PLFA, there was evidence of possible preservation. Hence, in low-moisture conditions, glycolipids may persist while phospholipids are preferentially hydrolyzed.
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Affiliation(s)
- Lori A Ziolkowski
- School of Geography and Earth Science, McMaster University, Hamilton, Ontario, Canada.
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18
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Azua-Bustos A, Urrejola C, Vicuña R. Life at the dry edge: microorganisms of the Atacama Desert. FEBS Lett 2012; 586:2939-45. [PMID: 22819826 DOI: 10.1016/j.febslet.2012.07.025] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 07/10/2012] [Accepted: 07/11/2012] [Indexed: 11/29/2022]
Abstract
The Atacama Desert, located in northern Chile, is the driest and oldest desert on Earth. Research aimed at the understanding of this unique habitat and its diverse microbial ecosystems begun only a few decades ago, mainly driven by NASA's astrobiology program. A milestone in these efforts was a paper published in 2003, when the Atacama was shown to be a proper model of Mars. From then on, studies have been focused to examine every possible niche suitable for microbial life in this extreme environment. Habitats as different as the underside of quartz rocks, fumaroles at the Andes Mountains, the inside of halite evaporates and caves of the Coastal Range, among others, have shown that life has found ingenious ways to adapt to extreme conditions such as low water availability, high salt concentration and intense UV radiation.
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Affiliation(s)
- Armando Azua-Bustos
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Chile
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19
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Stivaletta N, Barbieri R, Billi D. Microbial colonization of the salt deposits in the driest place of the Atacama Desert (Chile). ORIGINS LIFE EVOL B 2012; 42:187-200. [PMID: 22661023 DOI: 10.1007/s11084-012-9289-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2011] [Accepted: 02/13/2012] [Indexed: 11/27/2022]
Abstract
The Atacama Desert (Chile), one of the most arid places on Earth, shows hostile conditions for the development of epilithic microbial communities. In this study, we report the association of cyanobacteria (Chroococcidiopsis sp.) and bacteria belonging to Actinobacteria and Beta-Gammaproteobacteria and Firmicutes phyla inhabiting the near surface of salt (halite) deposits of the Salar Grande Basin, Atacama Desert (Chile). The halite deposits were investigated by using optical, confocal and field emission scanning electron microscopes, whereas culture-independent molecular techniques, 16S rDNA clone library, alongside RFLP analysis and 16S rRNA gene sequencing were applied to investigate the bacterial diversity. These microbial communities are an example of life that has adapted to extreme environmental conditions caused by dryness, high irradiation, and metal concentrations. Their adaptation is, therefore, important in the investigation of the environmental conditions that might be expected for life outside of Earth.
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Affiliation(s)
- Nunzia Stivaletta
- Dipartimento di Scienze della Terra e Geologico-Ambientali, Università di Bologna, Via Zamboni 67, 40126, Bologna, Italy.
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20
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Orcutt BN, Sylvan JB, Knab NJ, Edwards KJ. Microbial ecology of the dark ocean above, at, and below the seafloor. Microbiol Mol Biol Rev 2011; 75:361-422. [PMID: 21646433 PMCID: PMC3122624 DOI: 10.1128/mmbr.00039-10] [Citation(s) in RCA: 324] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The majority of life on Earth--notably, microbial life--occurs in places that do not receive sunlight, with the habitats of the oceans being the largest of these reservoirs. Sunlight penetrates only a few tens to hundreds of meters into the ocean, resulting in large-scale microbial ecosystems that function in the dark. Our knowledge of microbial processes in the dark ocean-the aphotic pelagic ocean, sediments, oceanic crust, hydrothermal vents, etc.-has increased substantially in recent decades. Studies that try to decipher the activity of microorganisms in the dark ocean, where we cannot easily observe them, are yielding paradigm-shifting discoveries that are fundamentally changing our understanding of the role of the dark ocean in the global Earth system and its biogeochemical cycles. New generations of researchers and experimental tools have emerged, in the last decade in particular, owing to dedicated research programs to explore the dark ocean biosphere. This review focuses on our current understanding of microbiology in the dark ocean, outlining salient features of various habitats and discussing known and still unexplored types of microbial metabolism and their consequences in global biogeochemical cycling. We also focus on patterns of microbial diversity in the dark ocean and on processes and communities that are characteristic of the different habitats.
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Affiliation(s)
- Beth N. Orcutt
- Center for Geomicrobiology, Aarhus University, 8000 Aarhus, Denmark
- Marine Environmental Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089
| | - Jason B. Sylvan
- Marine Environmental Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089
| | - Nina J. Knab
- Marine Environmental Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089
| | - Katrina J. Edwards
- Marine Environmental Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089
- Department of Earth Sciences, University of Southern California, Los Angeles, California 90089
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21
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Wierzchos J, Cámara B, de Los Ríos A, Davila AF, Sánchez Almazo IM, Artieda O, Wierzchos K, Gómez-Silva B, McKay C, Ascaso C. Microbial colonization of Ca-sulfate crusts in the hyperarid core of the Atacama Desert: implications for the search for life on Mars. GEOBIOLOGY 2011; 9:44-60. [PMID: 20726901 DOI: 10.1111/j.1472-4669.2010.00254.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The scarcity of liquid water in the hyperarid core of the Atacama Desert makes this region one of the most challenging environments for life on Earth. The low numbers of microbial cells in the soils suggest that within the Atacama Desert lies the dry limit for life on our planet. Here, we show that the Ca-sulfate crusts of this hyperarid core are the habitats of lithobiontic micro-organisms. This microporous, translucent substrate is colonized by epilithic lichens, as well as endolithic free-living algae, fungal hyphae, cyanobacteria and non photosynthetic bacteria. We also report a novel type of endolithic community, "hypoendoliths", colonizing the undermost layer of the crusts. The colonization of gypsum crusts within the hyperarid core appears to be controlled by the moisture regime. Our data shows that the threshold for colonization is crossed within the dry core, with abundant colonization in gypsum crusts at one study site, while crusts at a drier site are virtually devoid of life. We show that the cumulative time in 1 year of relative humidity (RH) above 60% is the best parameter to explain the difference in colonization between both sites. This is supported by controlled humidity experiments, where we show that colonies of endolithic cyanobacteria in the Ca-sulfate crust undergo imbibition process at RH >60%. Assuming that life once arose on Mars, it is conceivable that Martian micro-organisms sought refuge in similar isolated evaporite microenvironments during their last struggle for life as their planet turned arid.
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Affiliation(s)
- J Wierzchos
- Departamento de Ecologia de Sistemas, Instituto de Recursos Naturales, CCMA, CSIC, Madrid, Spain.
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22
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Lacap DC, Warren-Rhodes KA, McKay CP, Pointing SB. Cyanobacteria and chloroflexi-dominated hypolithic colonization of quartz at the hyper-arid core of the Atacama Desert, Chile. Extremophiles 2011; 15:31-8. [PMID: 21069402 PMCID: PMC3017302 DOI: 10.1007/s00792-010-0334-3] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Accepted: 10/22/2010] [Indexed: 11/28/2022]
Abstract
Quartz stones are ubiquitous in deserts and are a substrate for hypoliths, microbial colonists of the underside of such stones. These hypoliths thrive where extreme temperature and moisture stress limit the occurrence of higher plant and animal life. Several studies have reported the occurrence of green hypolithic colonization dominated by cyanobacteria. Here, we describe a novel red hypolithic colonization from Yungay, at the hyper-arid core of the Atacama Desert in Chile. Comparative analysis of green and red hypoliths from this site revealed markedly different microbial community structure as revealed by 16S rRNA gene clone libraries. Green hypoliths were dominated by cyanobacteria (Chroococcidiopsis and Nostocales phylotypes), whilst the red hypolith was dominated by a taxonomically diverse group of chloroflexi. Heterotrophic phylotypes common to all hypoliths were affiliated largely to desiccation-tolerant taxa within the Actinobacteria and Deinococci. Alphaproteobacterial phylotypes that affiliated with nitrogen-fixing taxa were unique to green hypoliths, whilst Gemmatimonadetes phylotypes occurred only on red hypolithon. Other heterotrophic phyla recovered with very low frequency were assumed to represent functionally relatively unimportant taxa.
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Affiliation(s)
- Donnabella C. Lacap
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | | | - Christopher P. McKay
- NASA-Ames Research Center, Mail Stop 245-3, Moffett Field, Mountain View, CA 94035 USA
| | - Stephen B. Pointing
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
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23
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Wong FKY, Lacap DC, Lau MCY, Aitchison JC, Cowan DA, Pointing SB. Hypolithic microbial community of quartz pavement in the high-altitude tundra of central Tibet. MICROBIAL ECOLOGY 2010; 60:730-9. [PMID: 20336290 PMCID: PMC2974210 DOI: 10.1007/s00248-010-9653-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Accepted: 02/26/2010] [Indexed: 05/05/2023]
Abstract
The hypolithic microbial community associated with quartz pavement at a high-altitude tundra location in central Tibet is described. A small-scale ecological survey indicated that 36% of quartz rocks were colonized. Community profiling using terminal restriction fragment length polymorphism revealed no significant difference in community structure among a number of colonized rocks. Real-time quantitative PCR and phylogenetic analysis of environmental phylotypes obtained from clone libraries were used to elucidate community structure across all domains. The hypolithon was dominated by cyanobacterial phylotypes (73%) with relatively low frequencies of other bacterial phylotypes, largely represented by the chloroflexi, actinobacteria, and bacteriodetes. Unidentified crenarchaeal phylotypes accounted for 4% of recoverable phylotypes, while algae, fungi, and mosses were indicated by a small fraction of recoverable phylotypes.
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Affiliation(s)
- Fiona K. Y. Wong
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR China
| | - Donnabella C. Lacap
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR China
| | - Maggie C. Y. Lau
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR China
| | - J. C. Aitchison
- Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR China
| | - Donald A. Cowan
- Institute for Microbial Biotechnology and Metagenomics, University of the Western Cape, Bellville, 7535 Cape Town, South Africa
| | - Stephen B. Pointing
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR China
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24
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Fairén AG, Davila AF, Lim D, Bramall N, Bonaccorsi R, Zavaleta J, Uceda ER, Stoker C, Wierzchos J, Dohm JM, Amils R, Andersen D, McKay CP. Astrobiology through the ages of Mars: the study of terrestrial analogues to understand the habitability of Mars. ASTROBIOLOGY 2010; 10:821-843. [PMID: 21087162 DOI: 10.1089/ast.2009.0440] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Mars has undergone three main climatic stages throughout its geological history, beginning with a water-rich epoch, followed by a cold and semi-arid era, and transitioning into present-day arid and very cold desert conditions. These global climatic eras also represent three different stages of planetary habitability: an early, potentially habitable stage when the basic requisites for life as we know it were present (liquid water and energy); an intermediate extreme stage, when liquid solutions became scarce or very challenging for life; and the most recent stage during which conditions on the surface have been largely uninhabitable, except perhaps in some isolated niches. Our understanding of the evolution of Mars is now sufficient to assign specific terrestrial environments to each of these periods. Through the study of Mars terrestrial analogues, we have assessed and constrained the habitability conditions for each of these stages, the geochemistry of the surface, and the likelihood for the preservation of organic and inorganic biosignatures. The study of these analog environments provides important information to better understand past and current mission results as well as to support the design and selection of instruments and the planning for future exploratory missions to Mars.
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25
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Northup DE, Snider JR, Spilde MN, Porter ML, van de Kamp JL, Boston PJ, Nyberg AM, Bargar JR. Diversity of rock varnish bacterial communities from Black Canyon, New Mexico. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jg001107] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Diana E. Northup
- Department of Biology; University of New Mexico; Albuquerque New Mexico USA
| | - Jessica R. Snider
- Department of Biology; University of New Mexico; Albuquerque New Mexico USA
| | - Michael N. Spilde
- Institute of Meteoritics; University of New Mexico; Albuquerque New Mexico USA
| | - Megan L. Porter
- Department of Biological Sciences; University of Maryland Baltimore County; Baltimore Maryland USA
| | | | - Penelope J. Boston
- Earth and Environmental Science Department; New Mexico Institute of Mining and Technology; Socorro New Mexico USA
| | - April M. Nyberg
- National Clonal Germplasm Repository; USDA-ARS; Corvallis Oregon USA
| | - John R. Bargar
- Stanford Synchrotron Radiation Laboratory; Menlo Park California USA
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26
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Gorbushina AA, Broughton WJ. Microbiology of the atmosphere-rock interface: how biological interactions and physical stresses modulate a sophisticated microbial ecosystem. Annu Rev Microbiol 2009; 63:431-50. [PMID: 19575564 DOI: 10.1146/annurev.micro.091208.073349] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Life at the atmosphere-lithosphere boundary is an ancient terrestrial niche that is sparsely covered by thin subaerial biofilms. The microbial inhabitants of these biofilms (a) have adapted to all types of terrestrial/subaerial stresses (e.g., desiccation, extreme temperatures, low nutrient availability, intense solar radiation), (b) interact with minerals that serve as both a dwelling and a source of mineral nutrients, and (c) provoke weathering of rocks and soil formation. Subaerial communities comprise heterotrophic and phototrophic microorganisms that support each other's lifestyle. Major lineages of eubacteria associated with the early colonization of land (e.g., Actinobacteria, Cyanobacteria) are present in these habitats along with eukaryotes such as microscopic green algae and ascomycetous fungi. The subaerial biofilm inhabitants have adapted to desiccation, solar radiation, and other environmental challenges by developing protective, melanized cell walls, assuming microcolonial architectures and symbiotic lifestyles. How these changes occurred, their significance in soil formation, and their potential as markers of climate change are discussed below.
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Affiliation(s)
- Anna A Gorbushina
- Department IV-Materials and Environment, BAM (Federal Institute for Material Research & Testing), D-Berlin 12205 , Germany.
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