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Popall RM, Postec A, Lecoeuvre A, Quéméneur M, Erauso G. Metabolic challenges and key players in serpentinite-hosted microbial ecosystems. Front Microbiol 2023; 14:1197823. [PMID: 37555067 PMCID: PMC10404738 DOI: 10.3389/fmicb.2023.1197823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/29/2023] [Indexed: 08/10/2023] Open
Abstract
Serpentinite-hosted systems are amongst the most challenging environments for life on Earth. Serpentinization, a geochemical alteration of exposed ultramafic rock, produces hydrothermal fluids enriched in abiotically derived hydrogen (H2), methane (CH4), and small organic molecules. The hyperalkaline pH of these fluids poses a great challenge for metabolic energy and nutrient acquisition, curbing the cellular membrane potential and limiting electron acceptor, carbon, and phosphorous availability. Nevertheless, serpentinization supports the growth of diverse microbial communities whose metabolic make-up might shed light on the beginning of life on Earth and potentially elsewhere. Here, we outline current hypotheses on metabolic energy production, carbon fixation, and nutrient acquisition in serpentinizing environments. A taxonomic survey is performed for each important metabolic function, highlighting potential key players such as H2 and CH4 cycling Serpentinimonas, Hydrogenophaga, Methanobacteriales, Methanosarcinales, and novel candidate phyla. Methodological biases of the available data and future approaches are discussed.
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Affiliation(s)
| | | | | | | | - Gaël Erauso
- Aix-Marseille Univ, Univ Toulon, CNRS, IRD, MIO, Marseille, France
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2
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Feehan B, Ran Q, Dorman V, Rumback K, Pogranichniy S, Ward K, Goodband R, Niederwerder MC, Lee STM. Novel complete methanogenic pathways in longitudinal genomic study of monogastric age-associated archaea. Anim Microbiome 2023; 5:35. [PMID: 37461084 DOI: 10.1186/s42523-023-00256-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 07/11/2023] [Indexed: 07/20/2023] Open
Abstract
BACKGROUND Archaea perform critical roles in the microbiome system, including utilizing hydrogen to allow for enhanced microbiome member growth and influencing overall host health. With the majority of microbiome research focusing on bacteria, the functions of archaea are largely still under investigation. Understanding methanogenic functions during the host lifetime will add to the limited knowledge on archaeal influence on gut and host health. In our study, we determined lifelong archaea dynamics, including detection and methanogenic functions, while assessing global, temporal and host distribution of our novel archaeal metagenome-assembled genomes (MAGs). We followed 7 monogastric swine throughout their life, from birth to adult (1-156 days of age), and collected feces at 22 time points. The samples underwent gDNA extraction, Illumina sequencing, bioinformatic quality and assembly processes, MAG taxonomic assignment and functional annotation. MAGs were utilized in downstream phylogenetic analysis for global, temporal and host distribution in addition to methanogenic functional potential determination. RESULTS We generated 1130 non-redundant MAGs, representing 588 unique taxa at the species level, with 8 classified as methanogenic archaea. The taxonomic classifications were as follows: orders Methanomassiliicoccales (5) and Methanobacteriales (3); genera UBA71 (3), Methanomethylophilus (1), MX-02 (1), and Methanobrevibacter (3). We recovered the first US swine Methanobrevibacter UBA71 sp006954425 and Methanobrevibacter gottschalkii MAGs. The Methanobacteriales MAGs were identified primarily during the young, preweaned host whereas Methanomassiliicoccales primarily in the adult host. Moreover, we identified our methanogens in metagenomic sequences from Chinese swine, US adult humans, Mexican adult humans, Swedish adult humans, and paleontological humans, indicating that methanogens span different hosts, geography and time. We determined complete metabolic pathways for all three methanogenic pathways: hydrogenotrophic, methylotrophic, and acetoclastic. This study provided the first evidence of acetoclastic methanogenesis in archaea of monogastric hosts which indicated a previously unknown capability for acetate utilization in methanogenesis for monogastric methanogens. Overall, we hypothesized that the age-associated detection patterns were due to differential substrate availability via the host diet and microbial metabolism, and that these methanogenic functions are likely crucial to methanogens across hosts. This study provided a comprehensive, genome-centric investigation of monogastric-associated methanogens which will further improve our understanding of microbiome development and functions.
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Affiliation(s)
- Brandi Feehan
- Division of Biology, College of Arts and Sciences, Kansas State University, Manhattan, KS, 66506, USA
| | - Qinghong Ran
- Division of Biology, College of Arts and Sciences, Kansas State University, Manhattan, KS, 66506, USA
| | - Victoria Dorman
- Division of Biology, College of Arts and Sciences, Kansas State University, Manhattan, KS, 66506, USA
| | - Kourtney Rumback
- Division of Biology, College of Arts and Sciences, Kansas State University, Manhattan, KS, 66506, USA
| | - Sophia Pogranichniy
- Division of Biology, College of Arts and Sciences, Kansas State University, Manhattan, KS, 66506, USA
| | - Kaitlyn Ward
- Division of Biology, College of Arts and Sciences, Kansas State University, Manhattan, KS, 66506, USA
| | - Robert Goodband
- Department of Animal Sciences and Industry, College of Agriculture, Kansas State University, Manhattan, KS, 66506, USA
| | | | - Sonny T M Lee
- Division of Biology, College of Arts and Sciences, Kansas State University, Manhattan, KS, 66506, USA.
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3
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Unique H 2-utilizing lithotrophy in serpentinite-hosted systems. THE ISME JOURNAL 2023; 17:95-104. [PMID: 36207493 PMCID: PMC9751293 DOI: 10.1038/s41396-022-01197-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 01/08/2022] [Accepted: 01/17/2022] [Indexed: 11/08/2022]
Abstract
Serpentinization of ultramafic rocks provides molecular hydrogen (H2) that can support lithotrophic metabolism of microorganisms, but also poses extremely challenging conditions, including hyperalkalinity and limited electron acceptor availability. Investigation of two serpentinization-active systems reveals that conventional H2-/CO2-dependent homoacetogenesis is thermodynamically unfavorable in situ due to picomolar CO2 levels. Through metagenomics and thermodynamics, we discover unique taxa capable of metabolism adapted to the habitat. This included a novel deep-branching phylum, "Ca. Lithacetigenota", that exclusively inhabits serpentinite-hosted systems and harbors genes encoding alternative modes of H2-utilizing lithotrophy. Rather than CO2, these putative metabolisms utilize reduced carbon compounds detected in situ presumably serpentinization-derived: formate and glycine. The former employs a partial homoacetogenesis pathway and the latter a distinct pathway mediated by a rare selenoprotein-the glycine reductase. A survey of microbiomes shows that glycine reductases are diverse and nearly ubiquitous in serpentinite-hosted environments. "Ca. Lithacetigenota" glycine reductases represent a basal lineage, suggesting that catabolic glycine reduction is an ancient bacterial innovation by Terrabacteria for gaining energy from geogenic H2 even under hyperalkaline, CO2-poor conditions. Unique non-CO2-reducing metabolisms presented here shed light on potential strategies that extremophiles may employ for overcoming a crucial obstacle in serpentinization-associated environments, features potentially relevant to primordial lithotrophy in early Earth.
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4
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Fones EM, Templeton AS, Mogk DW, Boyd ES. Transformation of low molecular weight organic acids by microbial endoliths in subsurface mafic and ultramafic igneous rock. Environ Microbiol 2022; 24:4137-4152. [PMID: 35590457 DOI: 10.1111/1462-2920.16041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 04/13/2022] [Accepted: 05/05/2022] [Indexed: 11/28/2022]
Abstract
A growing body of work indicates that continental subsurface rocks host a substantial portion of the Earth's biosphere. However, the activities of microbial cells inhabiting pore spaces and microfractures in subsurface rocks remain underexplored. Here, we develop and optimize microcosm assays to detect organic acid transformation activities of cells residing in mafic to ultramafic igneous rocks. Application of this assay to gabbro core from the Stillwater Mine, Montana, USA, revealed maximal methane production from acetate at temperatures approximating that of the mine. Controls show that these activities are not due to contamination introduced during drilling, exhumation, or laboratory processing of the core. The assay was then applied to rocks cored from the Samail Ophiolite, Oman, which is undergoing low temperature serpentinization. Production of i) carbon dioxide from acetate and formate and ii) methane from formate were detected in a dunite/harzburgite rock core interfacing pH 9.6 waters, and estimates of microbial activities were up to three orders of magnitude higher in the rock core pore space than in corresponding waters. The detection of endolithic microbial activities in igneous rocks has implications for life detection on other planetary bodies where similar rock types prevail, such as Mars, Europa, and Enceladus. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Elizabeth M Fones
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, 59717
| | - Alexis S Templeton
- Department of Geological Sciences, University of Colorado, Boulder, CO, 80309
| | - David W Mogk
- Department of Earth Sciences, Montana State University, Bozeman, MT, 59717
| | - Eric S Boyd
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, 59717
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5
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Bellucci M, Borruso L, Piergiacomo F, Brusetti L, Beneduce L. The effect of substituting energy crop with agricultural waste on the dynamics of bacterial communities in a two-stage anaerobic digester. CHEMOSPHERE 2022; 294:133776. [PMID: 35093420 DOI: 10.1016/j.chemosphere.2022.133776] [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: 11/15/2021] [Revised: 01/04/2022] [Accepted: 01/25/2022] [Indexed: 06/14/2023]
Abstract
The replacement of energy crops with agricultural waste in biogas production through anaerobic digestion (AD) is both an environmentally sustainable and economically profitable strategy. However, the change of feeding mix in AD might result in nutrient imbalance or increase of the ammonium concentration, negatively affecting the activity of the microbes responsible for the process. In the present study the structure and dynamics of the bacterial communities of a full-scale two-stage AD plant, composed of a hydrolysis/acidogenesis (H) and an acetogenesis/methanogenesis (M) tanks, was monitored during feedstock substitution. Energy crop (triticale) was replaced by poultry manure litter and olive mill pomace. The increase percentage of poultry manure litter (up to 8.6%) and olive mill pomace (up to 30.5%) in the recipe incremented the total solids (up to 21% in H) and, consequently, the nitrogen content in the digestate (6.7 g N/kg in the solid fraction in H and 4-5 g NH4+-N/L in the liquid fraction). This favored the growth of Lactococcus sp. with consequent increment of lactate production (∼ 1 mg L-1 last two days of the survey) and the establishment of Weissella and Lactobacillus spp. Syntrophic acetate-oxidizers, including Syntrophaceticus (6% ± 1.7%), were detected manly in M but were negatively affected by the addition of the poultry manure litter, while the sulfate-reducing bacteria correlated with the variations of the volatile fatty acids. Planctomycetes putatively capable of anammox process were also found in the H during the first two days of the survey and accounted for 0.3 ± 0.01% of the total bacterial community. The stability of the process during feedstock change is the result of the shift of bacterial populations of different functional groups that showed peculiar adaptation patterns in the two stages of the plant.
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Affiliation(s)
- M Bellucci
- Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA), Rome, 00144, Italy
| | - L Borruso
- Faculty of Science and Technology, Free University of Bolzano-Bozen, Piazza Università 1, 39100, Bolzano-Bozen, Italy
| | - F Piergiacomo
- Faculty of Science and Technology, Free University of Bolzano-Bozen, Piazza Università 1, 39100, Bolzano-Bozen, Italy
| | - L Brusetti
- Faculty of Science and Technology, Free University of Bolzano-Bozen, Piazza Università 1, 39100, Bolzano-Bozen, Italy
| | - L Beneduce
- Department of Agriculture, Food, Natural Resources and Engineering (DAFNE), University of Foggia, Via Napoli 25, 71122, Foggia, Italy.
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Bendia AG, Callefo F, Araújo MN, Sanchez E, Teixeira VC, Vasconcelos A, Battilani G, Pellizari VH, Rodrigues F, Galante D. Metagenome-Assembled Genomes from Monte Cristo Cave (Diamantina, Brazil) Reveal Prokaryotic Lineages As Functional Models for Life on Mars. ASTROBIOLOGY 2022; 22:293-312. [PMID: 34694925 DOI: 10.1089/ast.2021.0016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Microbial communities have been explored in various terrestrial subsurface ecosystems, showing metabolic potentials that could generate noteworthy morphological and molecular biosignatures. Recent advancements in bioinformatic tools have allowed for descriptions of novel and yet-to-be cultivated microbial lineages in different ecosystems due to the genome reconstruction approach from metagenomic data. Using shotgun metagenomic data, we obtained metagenome-assembled genomes related to cultivated and yet-to-be cultivated prokaryotic lineages from a silica and iron-rich cave (Monte Cristo) in Minas Gerais State, Brazil. The Monte Cristo Cave has been shown to possess a high diversity of genes involved with different biogeochemical cycles, including reductive and oxidative pathways related to carbon, sulfur, nitrogen, and iron. Three genomes were selected for pangenomic analysis, assigned as Truepera sp., Ca. Methylomirabilis sp., and Ca. Koribacter sp. based on their lifestyles (radiation resistance, anaerobic methane oxidation, and potential iron oxidation). These bacteria exhibit genes involved with multiple DNA repair strategies, starvation, and stress response. Because these groups have few reference genomes deposited in databases, our study adds important genomic information about these lineages. The combination of techniques applied in this study allowed us to unveil the potential relationships between microbial genomes and their ecological processes with the cave mineralogy and highlight the lineages involved with anaerobic methane oxidation, iron oxidation, and radiation resistance as functional models for the search for extant life-forms outside our planet in silica- and iron-rich environments and potentially on Mars.
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Affiliation(s)
- Amanda G Bendia
- Biological Oceanography Department, Oceanographic Institute, Universidade de São Paulo, São Paulo, Brazil
| | - Flavia Callefo
- Brazilian Synchrotron Light Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | - Maicon N Araújo
- Fundamental Chemistry Department, Institute of Chemistry, Universidade de São Paulo, São Paulo, Brazil
| | - Evelyn Sanchez
- Institute of Science and Technology, Federal University of the Jequitinhonha and Mucuri, Diamantina, Brazil
| | - Verônica C Teixeira
- Brazilian Synchrotron Light Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | - Alessandra Vasconcelos
- Institute of Science and Technology, Federal University of the Jequitinhonha and Mucuri, Diamantina, Brazil
| | - Gislaine Battilani
- Institute of Science and Technology, Federal University of the Jequitinhonha and Mucuri, Diamantina, Brazil
| | - Vivian H Pellizari
- Biological Oceanography Department, Oceanographic Institute, Universidade de São Paulo, São Paulo, Brazil
| | - Fabio Rodrigues
- Fundamental Chemistry Department, Institute of Chemistry, Universidade de São Paulo, São Paulo, Brazil
| | - Douglas Galante
- Brazilian Synchrotron Light Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
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7
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Fones EM, Colman DR, Kraus EA, Stepanauskas R, Templeton AS, Spear JR, Boyd ES. Diversification of methanogens into hyperalkaline serpentinizing environments through adaptations to minimize oxidant limitation. THE ISME JOURNAL 2021; 15:1121-1135. [PMID: 33257813 PMCID: PMC8115248 DOI: 10.1038/s41396-020-00838-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 10/28/2020] [Accepted: 11/11/2020] [Indexed: 01/29/2023]
Abstract
Metagenome assembled genomes (MAGs) and single amplified genomes (SAGs) affiliated with two distinct Methanobacterium lineages were recovered from subsurface fracture waters of the Samail Ophiolite, Sultanate of Oman. Lineage Type I was abundant in waters with circumneutral pH, whereas lineage Type II was abundant in hydrogen rich, hyperalkaline waters. Type I encoded proteins to couple hydrogen oxidation to CO2 reduction, typical of hydrogenotrophic methanogens. Surprisingly, Type II, which branched from the Type I lineage, lacked homologs of two key oxidative [NiFe]-hydrogenases. These functions were presumably replaced by formate dehydrogenases that oxidize formate to yield reductant and cytoplasmic CO2 via a pathway that was unique among characterized Methanobacteria, allowing cells to overcome CO2/oxidant limitation in high pH waters. This prediction was supported by microcosm-based radiotracer experiments that showed significant biological methane generation from formate, but not bicarbonate, in waters where the Type II lineage was detected in highest relative abundance. Phylogenetic analyses and variability in gene content suggested that recent and ongoing diversification of the Type II lineage was enabled by gene transfer, loss, and transposition. These data indicate that selection imposed by CO2/oxidant availability drove recent methanogen diversification into hyperalkaline waters that are heavily impacted by serpentinization.
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Affiliation(s)
- Elizabeth M. Fones
- grid.41891.350000 0001 2156 6108Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717 USA
| | - Daniel R. Colman
- grid.41891.350000 0001 2156 6108Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717 USA
| | - Emily A. Kraus
- grid.254549.b0000 0004 1936 8155Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO 80401 USA
| | - Ramunas Stepanauskas
- grid.296275.d0000 0000 9516 4913Bigelow Laboratory for Ocean Sciences, East Boothbay, ME 04544 USA
| | - Alexis S. Templeton
- grid.266190.a0000000096214564Department of Geological Sciences, University of Colorado, Boulder, CO 80309 USA
| | - John R. Spear
- grid.254549.b0000 0004 1936 8155Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO 80401 USA
| | - Eric S. Boyd
- grid.41891.350000 0001 2156 6108Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717 USA
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8
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Veneranda M, Lopez-Reyes G, Pascual Sanchez E, Krzesińska AM, Manrique-Martinez JA, Sanz-Arranz A, Lantz C, Lalla E, Moral A, Medina J, Poulet F, Dypvik H, Werner SC, Vago JL, Rull F. ExoMars Raman Laser Spectrometer: A Tool to Semiquantify the Serpentinization Degree of Olivine-Rich Rocks on Mars. ASTROBIOLOGY 2021; 21:307-322. [PMID: 33252242 DOI: 10.1089/ast.2020.2265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We evaluated the effectiveness of the ExoMars Raman laser spectrometer (RLS) to determine the degree of serpentinization of olivine-rich units on Mars. We selected terrestrial analogs of martian ultramafic rocks from the Leka Ophiolite Complex (LOC) and analyzed them with both laboratory and flight-like analytical instruments. We first studied the mineralogical composition of the samples (mostly olivine and serpentine) with state-of-the-art diffractometric (X-ray diffractometry [XRD]) and spectroscopic (Raman, near-infrared spectroscopy [NIR]) laboratory systems. We compared these results with those obtained using our RLS ExoMars Simulator. Our work shows that the RLS ExoMars Simulator successfully identified all major phases. Moreover, when emulating the automatic operating mode of the flight instrument, the RLS ExoMars Simulator also detected several minor compounds (pyroxene and brucite), some of which were not observed by NIR and XRD (e.g., calcite). Thereafter, we produced RLS-dedicated calibration curves (R2 between 0.9993 and 0.9995 with an uncertainty between ±3.0% and ±5.2% with a confidence interval of 95%) to estimate the relative content of olivine and serpentine in the samples. Our results show that RLS can be very effective in identifying serpentine, a scientific target of primary importance for the potential detection of biosignatures on Mars-the main objective of the ExoMars rover mission.
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Affiliation(s)
- Marco Veneranda
- Department of Condensed Matter Physics, Crystallography and Mineralogy, University of Valladolid, Valladolid, Spain
| | - Guillermo Lopez-Reyes
- Department of Condensed Matter Physics, Crystallography and Mineralogy, University of Valladolid, Valladolid, Spain
| | - Elena Pascual Sanchez
- Department of Condensed Matter Physics, Crystallography and Mineralogy, University of Valladolid, Valladolid, Spain
| | - Agata M Krzesińska
- Department of Geosciences, Centre for Earth Evolution and Dynamics, University of Oslo, Oslo, Norway
| | | | - Aurelio Sanz-Arranz
- Department of Condensed Matter Physics, Crystallography and Mineralogy, University of Valladolid, Valladolid, Spain
| | - Cateline Lantz
- Institut d'Astrophysique Spatiale, CNRS/Université Paris-Sud, Orsay, France
| | - Emmanuel Lalla
- Department of Earth and Space Science and Engineering, York University, Toronto, Canada
| | - Andoni Moral
- Department of Space Programs, Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain
| | - Jesús Medina
- Department of Condensed Matter Physics, Crystallography and Mineralogy, University of Valladolid, Valladolid, Spain
| | - Francois Poulet
- Institut d'Astrophysique Spatiale, CNRS/Université Paris-Sud, Orsay, France
| | - Henning Dypvik
- Department of Geosciences, Centre for Earth Evolution and Dynamics, University of Oslo, Oslo, Norway
| | - Stephanie C Werner
- Department of Geosciences, Centre for Earth Evolution and Dynamics, University of Oslo, Oslo, Norway
| | | | - Fernando Rull
- Department of Condensed Matter Physics, Crystallography and Mineralogy, University of Valladolid, Valladolid, Spain
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Cyanobacterial Mats in Calcite-Precipitating Serpentinite-Hosted Alkaline Springs of the Voltri Massif, Italy. Microorganisms 2020; 9:microorganisms9010062. [PMID: 33383678 PMCID: PMC7824716 DOI: 10.3390/microorganisms9010062] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/12/2020] [Accepted: 12/15/2020] [Indexed: 01/15/2023] Open
Abstract
(1) Background: Microbial communities in terrestrial, calcifying high-alkaline springs are not well understood. In this study, we investigate the structure and composition of microbial mats in ultrabasic (pH 10–12) serpentinite springs of the Voltri Massif (Italy). (2) Methods: Along with analysis of chemical and mineralogical parameters, environmental DNA was extracted and subjected to analysis of microbial communities based upon next-generation sequencing. (3) Results: Mineral precipitation and microbialite formation occurred, along with mat formation. Analysis of the serpentinite spring microbial community, based on Illumina sequencing of 16S rRNA amplicons, point to the relevance of alkaliphilic cyanobacteria, colonizing carbonate buildups. Cyanobacterial groups accounted for up to 45% of all retrieved sequences; 3–4 taxa were dominant, belonging to the filamentous groups of Leptolyngbyaceae, Oscillatoriales, and Pseudanabaenaceae. The cyanobacterial community found at these sites is clearly distinct from creek water sediment, highlighting their specific adaptation to these environments.
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10
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Physiological adaptations to serpentinization in the Samail Ophiolite, Oman. ISME JOURNAL 2019; 13:1750-1762. [PMID: 30872803 PMCID: PMC6588467 DOI: 10.1038/s41396-019-0391-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 02/08/2019] [Accepted: 02/28/2019] [Indexed: 11/30/2022]
Abstract
Hydration of ultramafic rock during the geologic process of serpentinization can generate reduced substrates that microorganisms may use to fuel their carbon and energy metabolisms. However, serpentinizing environments also place multiple constraints on microbial life by generating highly reduced hyperalkaline waters that are limited in dissolved inorganic carbon. To better understand how microbial life persists under these conditions, we performed geochemical measurements on waters from a serpentinizing environment and subjected planktonic microbial cells to metagenomic and physiological analyses. Metabolic potential inferred from metagenomes correlated with fluid type, and genes involved in anaerobic metabolisms were enriched in hyperalkaline waters. The abundance of planktonic cells and their rates of utilization of select single-carbon compounds were lower in hyperalkaline waters than alkaline waters. However, the ratios of substrate assimilation to dissimilation were higher in hyperalkaline waters than alkaline waters, which may represent adaptation to minimize energetic and physiologic stress imposed by highly reducing, carbon-limited conditions. Consistent with this hypothesis, estimated genome sizes and average oxidation states of carbon in inferred proteomes were lower in hyperalkaline waters than in alkaline waters. These data suggest that microorganisms inhabiting serpentinized waters exhibit a unique suite of physiological adaptations that allow for their persistence under these polyextremophilic conditions.
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11
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Sun X, Wang M, Guo L, Shu C, Zhang J, Geng L. Guanidine thiocyanate solution facilitates sample collection for plant rhizosphere microbiome analysis. PeerJ 2019; 7:e6440. [PMID: 30809445 PMCID: PMC6385689 DOI: 10.7717/peerj.6440] [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: 07/18/2018] [Accepted: 01/13/2019] [Indexed: 11/30/2022] Open
Abstract
The interactions between rhizosphere microorganisms and plants are important for the health and development of crops. Analysis of plant rhizosphere bacterial compositions, particularly of those with resistance to biotic/abiotic stresses, may improve their applications in sustainable agriculture. Large-scale rhizosphere samplings in the field are usually required; however, such samples, cannot be immediately frozen. We found that the storage of samples at room temperature for 2 days leads to a considerable reduction in the operational taxonomic unit (OTU) number and the indices of bacterial alpha-diversity of rhizosphere communities. In this study, in order to overcome these problems, we established a method using guanidine thiocyanate (GTC) solution for the preservation of rhizosphere samples after their collection. This method allowed the maintenance of the samples for at least 1 day at room temperature prior to their cryopreservation and was shown to be compatible with conventional DNA isolation protocols. Illumina sequencing of V3 and V4 hypervariable regions of the 16S rRNA gene was used to assess the feasibility and reliability of this method, and no significant differences were observed in the number of OTUs and in the Chao and Shannon indices between samples stored at −70 °C and those stored in GTC solution. Moreover, the representation of Pseudomonas spp. in samples stored in GTC solution was not significantly different from that in samples stored at −70 °C, as determined by real-time quantitative polymerase chain reaction (p > 0.05). Both types of samples were shown to cluster together according to principal coordinate analysis. Furthermore, GTC solution did not affect the bacterial taxon profiles at different storage periods compared with those observed when storing the samples below −70 °C. Even incubation of thawed samples (frozen at −70 °C) for 15 min at room temperature induced minor changes in the bacterial composition. Taken together, our results demonstrated that GTC solution may provide a reliable alternative for the preservation of rhizosphere samples in the field.
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Affiliation(s)
- Xiaoxiao Sun
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Meiling Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Lin Guo
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.,Department of Agronomy, Jinlin Agriculture University, Changchun, Jilin, China
| | - Changlong Shu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Lili Geng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
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12
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Kevbrin VV. Isolation and Cultivation of Alkaliphiles. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2019; 172:53-84. [DOI: 10.1007/10_2018_84] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Korzhenkov AA, Teplyuk AV, Lebedinsky AV, Khvashchevskaya AA, Kopylova YG, Arakchaa KD, Golyshin PN, Lunev EA, Golyshina OV, Kublanov IV, Toshchakov SV, Gavrilov SN. Members of the Uncultured Taxon OP1 (“Acetothermia”) Predominate in the Microbial Community of an Alkaline Hot Spring at East-Tuvinian Upland. Microbiology (Reading) 2018. [DOI: 10.1134/s0026261718060115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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14
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Jones RM, Goordial JM, Orcutt BN. Low Energy Subsurface Environments as Extraterrestrial Analogs. Front Microbiol 2018; 9:1605. [PMID: 30072971 PMCID: PMC6058055 DOI: 10.3389/fmicb.2018.01605] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 06/27/2018] [Indexed: 11/13/2022] Open
Abstract
Earth's subsurface is often isolated from phototrophic energy sources and characterized by chemotrophic modes of life. These environments are often oligotrophic and limited in electron donors or electron acceptors, and include continental crust, subseafloor oceanic crust, and marine sediment as well as subglacial lakes and the subsurface of polar desert soils. These low energy subsurface environments are therefore uniquely positioned for examining minimum energetic requirements and adaptations for chemotrophic life. Current targets for astrobiology investigations of extant life are planetary bodies with largely inhospitable surfaces, such as Mars, Europa, and Enceladus. Subsurface environments on Earth thus serve as analogs to explore possibilities of subsurface life on extraterrestrial bodies. The purpose of this review is to provide an overview of subsurface environments as potential analogs, and the features of microbial communities existing in these low energy environments, with particular emphasis on how they inform the study of energetic limits required for life. The thermodynamic energetic calculations presented here suggest that free energy yields of reactions and energy density of some metabolic redox reactions on Mars, Europa, Enceladus, and Titan could be comparable to analog environments in Earth's low energy subsurface habitats.
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Affiliation(s)
| | | | - Beth N. Orcutt
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States
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Frouin E, Bes M, Ollivier B, Quéméneur M, Postec A, Debroas D, Armougom F, Erauso G. Diversity of Rare and Abundant Prokaryotic Phylotypes in the Prony Hydrothermal Field and Comparison with Other Serpentinite-Hosted Ecosystems. Front Microbiol 2018; 9:102. [PMID: 29467733 PMCID: PMC5808123 DOI: 10.3389/fmicb.2018.00102] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 01/17/2018] [Indexed: 01/21/2023] Open
Abstract
The Bay of Prony, South of New Caledonia, represents a unique serpentinite-hosted hydrothermal field due to its coastal situation. It harbors both submarine and intertidal active sites, discharging hydrogen- and methane-rich alkaline fluids of low salinity and mild temperature through porous carbonate edifices. In this study, we have extensively investigated the bacterial and archaeal communities inhabiting the hydrothermal chimneys from one intertidal and three submarine sites by 16S rRNA gene amplicon sequencing. We show that the bacterial community of the intertidal site is clearly distinct from that of the submarine sites with species distribution patterns driven by only a few abundant populations, affiliated to the Chloroflexi and Proteobacteria phyla. In contrast, the distribution of archaeal taxa seems less site-dependent, as exemplified by the co-occurrence, in both submarine and intertidal sites, of two dominant phylotypes of Methanosarcinales previously thought to be restricted to serpentinizing systems, either marine (Lost City Hydrothermal Field) or terrestrial (The Cedars ultrabasic springs). Over 70% of the phylotypes were rare and included, among others, all those affiliated to candidate divisions. We finally compared the distribution of bacterial and archaeal phylotypes of Prony Hydrothermal Field with those of five previously studied serpentinizing systems of geographically distant sites. Although sensu stricto no core microbial community was identified, a few uncultivated lineages, notably within the archaeal order Methanosarcinales and the bacterial class Dehalococcoidia (the candidate division MSBL5) were exclusively found in a few serpentinizing systems while other operational taxonomic units belonging to the orders Clostridiales, Thermoanaerobacterales, or the genus Hydrogenophaga, were abundantly distributed in several sites. These lineages may represent taxonomic signatures of serpentinizing ecosystems. These findings extend our current knowledge of the microbial diversity inhabiting serpentinizing systems and their biogeography.
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Affiliation(s)
- Eléonore Frouin
- Aix-Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, Marseille, France
| | - Méline Bes
- Aix-Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, Marseille, France
| | - Bernard Ollivier
- Aix-Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, Marseille, France
| | - Marianne Quéméneur
- Aix-Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, Marseille, France
| | - Anne Postec
- Aix-Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, Marseille, France
| | - Didier Debroas
- CNRS UMR 6023, Laboratoire "Microorganismes - Génome et Environnement", Université Clermont Auvergne, Clermont-Ferrand, France
| | - Fabrice Armougom
- Aix-Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, Marseille, France
| | - Gaël Erauso
- Aix-Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, Marseille, France
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