1
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Sumner DY. Oxygenation of Earth's atmosphere induced metabolic and ecologic transformations recorded in the Lomagundi-Jatuli carbon isotopic excursion. Appl Environ Microbiol 2024; 90:e0009324. [PMID: 38819147 PMCID: PMC11218651 DOI: 10.1128/aem.00093-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 05/03/2024] [Indexed: 06/01/2024] Open
Abstract
The oxygenation of Earth's atmosphere represents the quintessential transformation of a planetary surface by microbial processes. In turn, atmospheric oxygenation transformed metabolic evolution; molecular clock models indicate the diversification and ecological expansion of respiratory metabolisms in the several hundred million years following atmospheric oxygenation. Across this same interval, the geological record preserves 13C enrichment in some carbonate rocks, called the Lomagundi-Jatuli excursion (LJE). By combining data from geologic and genomic records, a self-consistent metabolic evolution model emerges for the LJE. First, fermentation and methanogenesis were major processes remineralizing organic carbon before atmospheric oxygenation. Once an ozone layer formed, shallow water and exposed environments were shielded from UVB/C radiation, allowing the expansion of cyanobacterial primary productivity. High primary productivity and methanogenesis led to preferential removal of 12C into organic carbon and CH4. Extreme and variable 13C enrichments in carbonates were caused by 13C-depleted CH4 loss to the atmosphere. Through time, aerobic respiration diversified and became ecologically widespread, as did other new metabolisms. Respiration displaced fermentation and methanogenesis as the dominant organic matter remineralization processes. As CH4 loss slowed, dissolved inorganic carbon in shallow environments was no longer highly 13C enriched. Thus, the loss of extreme 13C enrichments in carbonates marks the establishment of a new microbial mat ecosystem structure, one dominated by respiratory processes distributed along steep redox gradients. These gradients allowed the exchange of metabolic by-products among metabolically diverse organisms, providing novel metabolic opportunities. Thus, the microbially induced oxygenation of Earth's atmosphere led to the transformation of microbial ecosystems, an archetypal example of planetary microbiology.IMPORTANCEThe oxygenation of Earth's atmosphere represents the most extensive known chemical transformation of a planetary surface by microbial processes. In turn, atmospheric oxygenation transformed metabolic evolution by providing oxidants independent of the sites of photosynthesis. Thus, the evolutionary changes during this interval and their effects on planetary-scale biogeochemical cycles are fundamental to our understanding of the interdependencies among genomes, organisms, ecosystems, elemental cycles, and Earth's surface chemistry through time.
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Affiliation(s)
- Dawn Y. Sumner
- Department of Earth and Planetary Sciences, University of California, Davis, Davis, California, USA
- Microbiology Graduate Group, University of California, Davis, Davis, California, USA
- Feminist Research Institute, University of California, Davis, Davis, California, USA
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2
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García-Maldonado JQ, Latisnere-Barragán H, Escobar-Zepeda A, Cadena S, Ramírez-Arenas PJ, Vázquez-Juárez R, Rojas-Contreras M, López-Cortés A. Revisiting Microbial Diversity in Hypersaline Microbial Mats from Guerrero Negro for a Better Understanding of Methanogenic Archaeal Communities. Microorganisms 2023; 11:microorganisms11030812. [PMID: 36985385 PMCID: PMC10059902 DOI: 10.3390/microorganisms11030812] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/21/2023] [Accepted: 02/23/2023] [Indexed: 03/30/2023] Open
Abstract
Knowledge regarding the diversity of methanogenic archaeal communities in hypersaline environments is limited because of the lack of efficient cultivation efforts as well as their low abundance and metabolic activities. In this study, we explored the microbial communities in hypersaline microbial mats. Bioinformatic analyses showed significant differences among the archaeal community structures for each studied site. Taxonomic assignment based on 16S rRNA and methyl coenzyme-M reductase (mcrA) gene sequences, as well as metagenomic analysis, corroborated the presence of Methanosarcinales. Furthermore, this study also provided evidence for the presence of Methanobacteriales, Methanomicrobiales, Methanomassiliicoccales, Candidatus Methanofastidiosales, Methanocellales, Methanococcales and Methanopyrales, although some of these were found in extremely low relative abundances. Several mcrA environmental sequences were significantly different from those previously reported and did not match with any known methanogenic archaea, suggesting the presence of specific environmental clusters of methanogenic archaea in Guerrero Negro. Based on functional inference and the detection of specific genes in the metagenome, we hypothesised that all four methanogenic pathways were able to occur in these environments. This study allowed the detection of extremely low-abundance methanogenic archaea, which were highly diverse and with unknown physiology, evidencing the presence of all methanogenic metabolic pathways rather than the sheer existence of exclusively methylotrophic methanogenic archaea in hypersaline environments.
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Affiliation(s)
- José Q García-Maldonado
- Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Unidad Mérida, Mérida 97310, Yucatán, Mexico
| | - Hever Latisnere-Barragán
- Centro de Investigaciones Biológicas del Noroeste (CIBNOR), La Paz 23205, Baja California Sur, Mexico
| | | | - Santiago Cadena
- Centro de Investigaciones Químicas, Universidad Autónoma del Estado de Morelos, Cuernavaca 62209, Morelos, Mexico
| | - Patricia J Ramírez-Arenas
- Centro de Investigaciones Biológicas del Noroeste (CIBNOR), La Paz 23205, Baja California Sur, Mexico
| | - Ricardo Vázquez-Juárez
- Centro de Investigaciones Biológicas del Noroeste (CIBNOR), La Paz 23205, Baja California Sur, Mexico
| | - Maurilia Rojas-Contreras
- Departamento de Agronomía, Universidad Autónoma de Baja California Sur, La Paz 23080, Baja California Sur, Mexico
| | - Alejandro López-Cortés
- Centro de Investigaciones Biológicas del Noroeste (CIBNOR), La Paz 23205, Baja California Sur, Mexico
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3
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Pavloudi C, Zafeiropoulos H. Deciphering the community structure and the functional potential of a hypersaline marsh microbial mat community. FEMS Microbiol Ecol 2022; 98:6843573. [PMID: 36416806 DOI: 10.1093/femsec/fiac141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/31/2022] [Accepted: 11/21/2022] [Indexed: 11/24/2022] Open
Abstract
Microbial mats are vertically stratified communities of microorganisms characterized by pronounced physiochemical gradients allowing for high species diversity and a wide range of metabolic capabilities. High Throughput Sequencing has the potential to reveal the biodiversity and function of such ecosystems in the cycling of elements. The present study combines 16S rRNA amplicon sequencing and shotgun metagenomics on a hypersaline marsh in Tristomo bay (Karpathos, Greece). Samples were collected in July 2018 and November 2019 from microbial mats, deeper sediment, aggregates observed in the water overlying the sediment, as well as sediment samples with no apparent layering. Metagenomic samples' coassembly and binning revealed 250 bacterial and 39 archaeal metagenome-assembled genomes, with completeness estimates higher than 70% and contamination less than 5%. All MAGs had KEGG Orthology terms related to osmoadaptation, with the 'salt in' strategy ones being prominent. Halobacteria and Bacteroidetes were the most abundant taxa in the mats. Photosynthesis was most likely performed by purple sulphur and nonsulphur bacteria. All samples had the capacity for sulphate reduction, dissimilatory arsenic reduction, and conversion of pyruvate to oxaloacetate. Overall, both sequencing methodologies resulted in similar taxonomic compositions and revealed that the formation of the microbial mat in this marsh exhibits seasonal variation.
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Affiliation(s)
- Christina Pavloudi
- Institute of Marine Biology, Biotechnology and Aquaculture (IMBBC), Hellenic Centre for Marine Research (HCMR), P.O. Box 2214, 71003, Heraklion, Crete, Greece.,Department of Biological Sciences, The George Washington University, 2029 G St NW, Bell Hall 302, Washington DC 20052, United States
| | - Haris Zafeiropoulos
- Institute of Marine Biology, Biotechnology and Aquaculture (IMBBC), Hellenic Centre for Marine Research (HCMR), P.O. Box 2214, 71003, Heraklion, Crete, Greece.,Department of Biology, University of Crete, Voutes University Campus, P.O. Box 2208, 70013, Heraklion, Crete, Greece.,Laboratory of Molecular Bacteriology, Rega Institute for Medical Research, Department of Microbiology, Immunology and Transplantation, KU Leuven, Herestraat 49, box 1028, 3000 Leuven, Belgium
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4
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Medina-Chávez NO, Travisano M. Archaeal Communities: The Microbial Phylogenomic Frontier. Front Genet 2022; 12:693193. [PMID: 35154237 PMCID: PMC8826477 DOI: 10.3389/fgene.2021.693193] [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: 04/10/2021] [Accepted: 11/22/2021] [Indexed: 11/17/2022] Open
Abstract
Archaea are a unique system for investigating the diversity of life. There are the most diverse group of organisms with the longest evolutionary history of life on Earth. Phylogenomic investigations reveal the complex evolutionary history of Archaea, overturning longstanding views of the history of life. They exist in the harshest environments and benign conditions, providing a system to investigate the basis for living in extreme environments. They are frequently members of microbial communities, albeit generally rare. Archaea were central in the evolution of Eukaryotes and can be used as a proxy for studying life on other planets. Future advances will depend not only upon phylogenomic studies but also on a better understanding of isolation and cultivation techniques.
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Affiliation(s)
- Nahui Olin Medina-Chávez
- Ecology, Evolution and Behavior, University of Minnesota, St. Paul, MN, United States.,BioTechnology Institute, University of Minnesota, St. Paul, MN, United States
| | - Michael Travisano
- Ecology, Evolution and Behavior, University of Minnesota, St. Paul, MN, United States.,BioTechnology Institute, University of Minnesota, St. Paul, MN, United States.,Minnesota Center for the Philosophy of Science, University of Minnesota, Minneapolis, MN, United States
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5
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Metabarcoding under Brine: Microbial Ecology of Five Hypersaline Lakes at Rottnest Island (WA, Australia). WATER 2021. [DOI: 10.3390/w13141899] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Hypersaline ecosystems—aquatic environments where concentration of salt exceeds 35 g L−1—host microbial communities that are highly specialised to cope with these extreme conditions. However, our knowledge on the taxonomic diversity and functional metabolisms characterising microbial communities in the water columns of hypersaline ecosystems is still limited, and this may compromise the future preservation of these unique environments. DNA metabarcoding provides a reliable and affordable tool to investigate environmental dynamics of aquatic ecosystems, and its use in brine can be highly informative. Here, we make use of bacterial 16S metabarcoding techniques combined with hydrochemical analyses to investigate the microbial patterns (diversity and functions) from five hypersaline lakes located at Rottnest Island (WA). Our results indicate lake-driven microbial aquatic assemblages that are characterised by taxonomically and functionally moderately to extremely halophilic groups, with TDS (total dissolved solids) and alkalinity amongst the most influential parameters driving the community patterns. Overall, our findings suggest that DNA metabarcoding allows rapid but reliable ecological assessment of the hypersaline aquatic microbial communities at Rottnest Island. Further studies involving different hypersaline lakes across multiple seasons will help elucidate the full extent of the potential of this tool in brine.
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Methanogenesis at High Temperature, High Ionic Strength and Low pH in the Volcanic Area of Dallol, Ethiopia. Microorganisms 2021; 9:microorganisms9061231. [PMID: 34204110 PMCID: PMC8228321 DOI: 10.3390/microorganisms9061231] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/03/2021] [Accepted: 06/04/2021] [Indexed: 11/17/2022] Open
Abstract
The Dallol geothermal area originated as a result of seismic activity and the presence of a shallow underground volcano, both due to the divergence of two tectonic plates. In its ascent, hot water dissolves and drags away the subsurface salts. The temperature of the water that comes out of the chimneys is higher than 100 °C, with a pH close to zero and high mineral concentration. These factors make Dallol a polyextreme environment. So far, nanohaloarchaeas, present in the salts that form the walls of the chimneys, have been the only living beings reported in this extreme environment. Through the use of complementary techniques: culture in microcosms, methane stable isotope signature and hybridization with specific probes, the methanogenic activity in the Dallol area has been assessed. Methane production in microcosms, positive hybridization with the Methanosarcinales probe and the δ13CCH4-values measured, show the existence of extensive methanogenic activity in the hydrogeothermic Dallol system. A methylotrophic pathway, carried out by Methanohalobium and Methanosarcina-like genera, could be the dominant pathway for methane production in this environment.
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7
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Jahnke LL, Des Marais DJ. Carbon isotopic composition of lipid biomarkers from an endoevaporitic gypsum crust microbial mat reveals cycling of mineralized organic carbon. GEOBIOLOGY 2019; 17:643-659. [PMID: 31361088 DOI: 10.1111/gbi.12355] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 06/02/2019] [Accepted: 06/23/2019] [Indexed: 06/10/2023]
Abstract
Microbial mats that inhabit gypsum deposits in ponds at Guerrero Negro, Baja California Sur, Mexico, developed distinct pigmented horizons that provided an opportunity to examine the fixation and flow of carbon through a trophic structure and, in conjunction with previous phylogenetic analyses, to assess the diagenetic fates of molecular δ13 C biosignatures. The δ13 C values of individual biomarker lipids, total carbon, and total organic carbon (TOC) were determined for each of the following horizons: tan-orange (TO) at the surface, green (G), purple (P), and olive-black (OB) at the bottom. δ13 C of individual fatty acids from intact polar lipids (IPFA) in TO were similar to δ13 C of dissolved inorganic carbon (DIC) in the overlying water column, indicating limited discrimination by cyanobacteria during CO2 fixation. δ13 CTOC of the underlying G was 3‰ greater than that of TO. The most δ13 C-depleted acetogenic lipids in the upper horizons were the cyanobacterial biomarkers C17 n-alkanes and polyunsaturated fatty acids. Bishomohopanol was 4 to 7‰ enriched, relative to alkanes and intact polar fatty acids (IPFA), respectively. Acyclic C20 isoprenoids were depleted by 14‰ relative to bishomohopanol. Significantly, ∆[δ13 CTOC - δ13 C∑IPFA ] increased from 6.9‰ in TO to 14.7‰ in OB. This major trend might indicate that 13 C-enriched residual organic matter accumulated at depth. The permanently anoxic P horizon was dominated by anoxygenic phototrophs and sulfate-reducing bacteria. P hosted an active sulfur-dependent microbial community. IPFA and bishomohopanol were 13 C-depleted relative to upper crust by 7 and 4‰, respectively, and C20 isoprenoids were somewhat 13 C-enriched. Synthesis of alkanes in P was evidenced only by 13 C-depleted n-octadecane and 8-methylhexadecane. In OB, the marked increase of total inorganic carbon δ13 C (δ13 CTIC ) of >6‰ perhaps indicated terminal mineralization. This δ13 CTIC increase is consistent with degradation of the osmolyte glycine betaine by methylotrophic methanogens and loss of 13 C-depleted methane from the mat.
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Affiliation(s)
- Linda L Jahnke
- Exobiology Branch, Space Science & Astrobiology Division, NASA-Ames Research Center, Moffett Field, CA, USA
| | - David J Des Marais
- Exobiology Branch, Space Science & Astrobiology Division, NASA-Ames Research Center, Moffett Field, CA, USA
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8
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Guan Y, Ngugi DK, Vinu M, Blom J, Alam I, Guillot S, Ferry JG, Stingl U. Comparative Genomics of the Genus Methanohalophilus, Including a Newly Isolated Strain From Kebrit Deep in the Red Sea. Front Microbiol 2019; 10:839. [PMID: 31068917 PMCID: PMC6491703 DOI: 10.3389/fmicb.2019.00839] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 04/02/2019] [Indexed: 01/25/2023] Open
Abstract
Halophilic methanogens play an important role in the carbon cycle in hypersaline environments, but are under-represented in culture collections. In this study, we describe a novel Methanohalophilus strain that was isolated from the sulfide-rich brine-seawater interface of Kebrit Deep in the Red Sea. Based on physiological and phylogenomic features, strain RSK, which is the first methanogenic archaeon to be isolated from a deep hypersaline anoxic brine lake of the Red Sea, represents a novel species of this genus. In order to compare the genetic traits underpinning the adaptations of this genus in diverse hypersaline environments, we sequenced the genome of strain RSK and compared it with genomes of previously isolated and well characterized species in this genus (Methanohalophilus mahii, Methanohalophilus halophilus, Methanohalophilus portucalensis, and Methanohalophilus euhalobius). These analyses revealed a highly conserved genomic core of greater than 93% of annotated genes (1490 genes) containing pathways for methylotrophic methanogenesis, osmoprotection through salt-out strategy, and oxidative stress response, among others. Despite the high degree of genomic conservation, species-specific differences in sulfur and glycogen metabolisms, viral resistance, amino acid, and peptide uptake machineries were also evident. Thus, while Methanohalophilus species are found in diverse extreme environments, each genotype also possesses adaptive traits that are likely relevant in their respective hypersaline habitats.
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Affiliation(s)
- Yue Guan
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - David K. Ngugi
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Manikandan Vinu
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Jochen Blom
- Bioinformatik und Systembiologie, Justus-Liebig-Universität Giessen, Giessen, Germany
| | - Intikhab Alam
- Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Sylvain Guillot
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - James G. Ferry
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States
| | - Ulrich Stingl
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- Department of Microbiology and Cell Science, UF/IFAS Fort Lauderdale Research and Education Center, University of Florida, Davie, FL, United States
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9
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Gregory SP, Barnett MJ, Field LP, Milodowski AE. Subsurface Microbial Hydrogen Cycling: Natural Occurrence and Implications for Industry. Microorganisms 2019; 7:E53. [PMID: 30769950 PMCID: PMC6407114 DOI: 10.3390/microorganisms7020053] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 02/01/2019] [Accepted: 02/03/2019] [Indexed: 12/21/2022] Open
Abstract
Hydrogen is a key energy source for subsurface microbial processes, particularly in subsurface environments with limited alternative electron donors, and environments that are not well connected to the surface. In addition to consumption of hydrogen, microbial processes such as fermentation and nitrogen fixation produce hydrogen. Hydrogen is also produced by a number of abiotic processes including radiolysis, serpentinization, graphitization, and cataclasis of silicate minerals. Both biotic and abiotically generated hydrogen may become available for consumption by microorganisms, but biotic production and consumption are usually tightly coupled. Understanding the microbiology of hydrogen cycling is relevant to subsurface engineered environments where hydrogen-cycling microorganisms are implicated in gas consumption and production and corrosion in a number of industries including carbon capture and storage, energy gas storage, and radioactive waste disposal. The same hydrogen-cycling microorganisms and processes are important in natural sites with elevated hydrogen and can provide insights into early life on Earth and life on other planets. This review draws together what is known about microbiology in natural environments with elevated hydrogen, and highlights where similar microbial populations could be of relevance to subsurface industry.
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Affiliation(s)
- Simon P Gregory
- British Geological Survey, Environmental Science Centre, Keyworth, Nottingham NG12 5GG, UK.
| | - Megan J Barnett
- British Geological Survey, Environmental Science Centre, Keyworth, Nottingham NG12 5GG, UK.
| | - Lorraine P Field
- British Geological Survey, Environmental Science Centre, Keyworth, Nottingham NG12 5GG, UK.
| | - Antoni E Milodowski
- British Geological Survey, Environmental Science Centre, Keyworth, Nottingham NG12 5GG, UK.
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10
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García-Maldonado JQ, Escobar-Zepeda A, Raggi L, Bebout BM, Sanchez-Flores A, López-Cortés A. Bacterial and archaeal profiling of hypersaline microbial mats and endoevaporites, under natural conditions and methanogenic microcosm experiments. Extremophiles 2018; 22:903-916. [PMID: 30120599 DOI: 10.1007/s00792-018-1047-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 08/08/2018] [Indexed: 11/29/2022]
Abstract
Bacterial and archaeal community structure of five microbial communities, developing at different salinities in Baja California Sur, Mexico, were characterized by 16S rRNA sequencing. The response of the microbial community to artificial changes in salinity-sulfate concentrations and to addition of trimethylamine was also evaluated in microcosm experiments. Ordination analyses of the microbial community structure showed that microbial composition was distinctive for each hypersaline site. Members of bacteria were dominated by Bacteroidetes and Proteobacteria phyla, while Halobacteria of the Euryarchaeota phylum was the most represented class of archaea for all the environmental samples. At a higher phylogenetic resolution, methanogenic communities were dominated by members of the Methanosarcinales, Methanobacteriales and Methanococcales orders. Incubation experiments showed that putative hydrogenotrophic methanogens of the Methanomicrobiales increased in abundance only under lowest salinity and sulfate concentrations. Trimethylamine addition effectively increased the abundance of methylotrophic members from the Methanosarcinales, but also increased the relative abundance of the Thermoplasmata class, suggesting the potential capability of these microorganisms to use trimethylamine in hypersaline environments. These results contribute to the knowledge of microbial diversity in hypersaline environments from Baja California Sur, Mexico, and expand upon the available information for uncultured methanogenic archaea in these ecosystems.
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Affiliation(s)
- José Q García-Maldonado
- CONACYT - Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Unidad Mérida, Antigua Carretera a Progreso Km. 6, Yucatán, 97310, Mexico.
| | - Alejandra Escobar-Zepeda
- Unidad Universitaria de Secuenciación Masiva y Bioinformática, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Mexico, Mexico
| | - Luciana Raggi
- CONACYT - Instituto de Investigaciones Agropecuarias y Forestales, Universidad Michoacana San Nicolás de Hidalgo, Morelia, Michoacán, Mexico
| | - Brad M Bebout
- Exobiology Branch, Ames Research Center, National Aeronautics and Space Administration, Moffett Field, CA, USA
| | - Alejandro Sanchez-Flores
- Unidad Universitaria de Secuenciación Masiva y Bioinformática, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Mexico, Mexico
| | - Alejandro López-Cortés
- Laboratorio de Geomicrobiología y Biotecnología, Instituto Politécnico Nacional 195, Centro de Investigaciones Biológicas del Noroeste, Playa Palo de Santa Rita Sur, La Paz, Baja California Sur, 23096, Mexico.
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11
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Cadena S, García-Maldonado JQ, López-Lozano NE, Cervantes FJ. Methanogenic and Sulfate-Reducing Activities in a Hypersaline Microbial Mat and Associated Microbial Diversity. MICROBIAL ECOLOGY 2018; 75:930-940. [PMID: 29116347 DOI: 10.1007/s00248-017-1104-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 10/30/2017] [Indexed: 06/07/2023]
Abstract
Methanogenesis and sulfate reduction are important microbial processes in hypersaline environments. However, key aspects determining substrate competition between these microbial processes have not been well documented. We evaluated competitive and non-competitive substrates for stimulation of both processes through microcosm experiments of hypersaline microbial mat samples from Guerrero Negro, Baja California Sur, Mexico, and we assessed the effect of these substrates on the microbial community composition. Methylotrophic methanogenesis evidenced by sequences belonging to methanogens of the family Methanosarcinaceae was found as the dominant methanogenic pathway in the studied hypersaline microbial mat. Nevertheless, our results showed that incubations supplemented with acetate and lactate, performed in absence of sulfate, also produced methane after 40 days of incubation, apparently driven by hydrogenotrophic methanogens affiliated to the family Methanomicrobiaceae. Sulfate reduction was mainly stimulated by addition of acetate and lactate; however, after 40 days of incubation, an increase of the H2S concentrations in microcosms amended with trimethylamine and methanol was also observed, suggesting that these substrates are putatively used for sulfate reduction. Moreover, 16S rRNA gene sequencing analysis showed remarkable differences in the microbial community composition among experimental treatments. In the analyzed sample amended with acetate, sulfate-reducing bacteria (SRB) belonging to the family Desulfobacteraceae were dominant, while members of Desulfohalobiaceae, Desulfomicrobiaceae, and Desulfovibrionaceae were found in the incubation with lactate. Additionally, we detected an unexpected high abundance of unclassified Hydrogenedentes (near 25%) in almost all the experimental treatments. This study contributes to better understand methanogenic and sulfate-reducing activities, which play an important role in the functioning of hypersaline environments.
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Affiliation(s)
- Santiago Cadena
- Instituto Potosino de Investigación Científica y Tecnológica, IPICYT, División de Ciencias Ambientales, San Luis Potosí, Mexico
- Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Unidad Mérida, Mérida, Yucatán, Mexico
| | - José Q García-Maldonado
- CONACYT-Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Departamento de Recursos del Mar, Unidad Mérida, Mérida, Yucatán, Mexico
| | - Nguyen E López-Lozano
- CONACYT-Instituto Potosino de Investigación Científica y Tecnológica, IPICYT, División de Ciencias Ambientales, San Luis Potosí, Mexico.
| | - Francisco J Cervantes
- Instituto Potosino de Investigación Científica y Tecnológica, IPICYT, División de Ciencias Ambientales, San Luis Potosí, Mexico.
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12
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Sorokin DY, Makarova KS, Abbas B, Ferrer M, Golyshin PN, Galinski EA, Ciordia S, Mena MC, Merkel AY, Wolf YI, van Loosdrecht MCM, Koonin EV. Discovery of extremely halophilic, methyl-reducing euryarchaea provides insights into the evolutionary origin of methanogenesis. Nat Microbiol 2017; 2:17081. [PMID: 28555626 PMCID: PMC5494993 DOI: 10.1038/nmicrobiol.2017.81] [Citation(s) in RCA: 149] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 04/18/2017] [Indexed: 01/24/2023]
Abstract
Methanogenic archaea are major players in the global carbon cycle and in the biotechnology of anaerobic digestion. The phylum Euryarchaeota includes diverse groups of methanogens that are interspersed with non-methanogenic lineages. So far, methanogens inhabiting hypersaline environments have been identified only within the order Methanosarcinales. We report the discovery of a deep phylogenetic lineage of extremophilic methanogens in hypersaline lakes and present analysis of two nearly complete genomes from this group. Within the phylum Euryarchaeota, these isolates form a separate, class-level lineage 'Methanonatronarchaeia' that is most closely related to the class Halobacteria. Similar to the Halobacteria, 'Methanonatronarchaeia' are extremely halophilic and do not accumulate organic osmoprotectants. The high intracellular concentration of potassium implies that 'Methanonatronarchaeia' employ the 'salt-in' osmoprotection strategy. These methanogens are heterotrophic methyl-reducers that use C1-methylated compounds as electron acceptors and formate or hydrogen as electron donors. The genomes contain an incomplete and apparently inactivated set of genes encoding the upper branch of methyl group oxidation to CO2 as well as membrane-bound heterodisulfide reductase and cytochromes. These features differentiate 'Methanonatronarchaeia' from all known methyl-reducing methanogens. The discovery of extremely halophilic, methyl-reducing methanogens related to haloarchaea provides insights into the origin of methanogenesis and shows that the strategies employed by methanogens to thrive in salt-saturating conditions are not limited to the classical methylotrophic pathway.
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Affiliation(s)
- Dimitry Y Sorokin
- Winogradsky Institute of Microbiology, Centre for Biotechnology, Russian Academy of Sciences, Moscow, Russia.,Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | - Ben Abbas
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | | | - Peter N Golyshin
- School of Biological Sciences, Bangor University, Gwynedd LL57 2UW, UK
| | - Erwin A Galinski
- Institute of Microbiology and Biotechnology, Rheinische Friedrich-Wilhelms University, Bonn, Germany
| | - Sergio Ciordia
- Proteomics Facility, Centro Nacional de Biotecnología, CSIC, Madrid, Spain
| | - María Carmen Mena
- Proteomics Facility, Centro Nacional de Biotecnología, CSIC, Madrid, Spain
| | - Alexander Y Merkel
- Winogradsky Institute of Microbiology, Centre for Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Yuri I Wolf
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | | | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
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13
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McKay CP, Rask JC, Detweiler AM, Bebout BM, Everroad RC, Lee JZ, Chanton JP, Mayer MH, Caraballo AAL, Kapili B, Al-Awar M, Al-Farraj A. An Unusual Inverted Saline Microbial Mat Community in an Interdune Sabkha in the Rub' al Khali (the Empty Quarter), United Arab Emirates. PLoS One 2016; 11:e0150342. [PMID: 26982497 PMCID: PMC4794207 DOI: 10.1371/journal.pone.0150342] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 02/14/2016] [Indexed: 11/23/2022] Open
Abstract
Salt flats (sabkha) are a recognized habitat for microbial life in desert environments and as analogs of habitats for possible life on Mars. Here we report on the physical setting and microbiology of interdune sabkhas among the large dunes in the Rub' al Khali (the Empty Quarter) in Liwa Oasis, United Arab Emirates. The salt flats, composed of gypsum and halite, are moistened by relatively fresh ground water. The result is a salinity gradient that is inverted compared to most salt flat communities with the hypersaline layer at the top and freshwater layers below. We describe and characterize a rich photosynthetically-based microbial ecosystem that is protected from the arid outside environment by a translucent salt crust. Gases collected from sediments under shallow ponds in the sabkha contain methane in concentrations as high as 3400 ppm. The salt crust could preserve biomarkers and other evidence for life in the salt after it dries out. Chloride-filled depressions have been identified on Mars and although surface flow of water is unlikely on Mars today, ground water is possible. Such a near surface system with modern groundwater flowing under ancient salt deposits could be present on Mars and could be accessed by surface rovers.
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Affiliation(s)
- Christopher P. McKay
- NASA Ames Research Center, Moffett Field, California, United States of America
- * E-mail:
| | - Jon C. Rask
- NASA Ames Research Center, Moffett Field, California, United States of America
| | - Angela M. Detweiler
- NASA Ames Research Center, Moffett Field, California, United States of America
- Bay Area Environmental Research Institute, Petaluma, California, United States of America
| | - Brad M. Bebout
- NASA Ames Research Center, Moffett Field, California, United States of America
| | - R. Craig Everroad
- NASA Ames Research Center, Moffett Field, California, United States of America
- Bay Area Environmental Research Institute, Petaluma, California, United States of America
| | - Jackson Z. Lee
- NASA Ames Research Center, Moffett Field, California, United States of America
- Bay Area Environmental Research Institute, Petaluma, California, United States of America
| | - Jeffrey P. Chanton
- Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, Florida, United States of America
| | - Marisa H. Mayer
- NASA Ames Research Center, Moffett Field, California, United States of America
| | | | - Bennett Kapili
- NASA Ames Research Center, Moffett Field, California, United States of America
| | - Meshgan Al-Awar
- Research and Studies Center, Dubai Police Academy, Dubai, United Arab Emirates
| | - Asma Al-Farraj
- Geography Department, United Arab Emirates University, Al Ain, United Arab Emirates
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14
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Kietäväinen R, Purkamo L. The origin, source, and cycling of methane in deep crystalline rock biosphere. Front Microbiol 2015; 6:725. [PMID: 26236303 PMCID: PMC4505394 DOI: 10.3389/fmicb.2015.00725] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 07/02/2015] [Indexed: 11/13/2022] Open
Abstract
The emerging interest in using stable bedrock formations for industrial purposes, e.g., nuclear waste disposal, has increased the need for understanding microbiological and geochemical processes in deep crystalline rock environments, including the carbon cycle. Considering the origin and evolution of life on Earth, these environments may also serve as windows to the past. Various geological, chemical, and biological processes can influence the deep carbon cycle. Conditions of CH4 formation, available substrates and time scales can be drastically different from surface environments. This paper reviews the origin, source, and cycling of methane in deep terrestrial crystalline bedrock with an emphasis on microbiology. In addition to potential formation pathways of CH4, microbial consumption of CH4 is also discussed. Recent studies on the origin of CH4 in continental bedrock environments have shown that the traditional separation of biotic and abiotic CH4 by the isotopic composition can be misleading in substrate-limited environments, such as the deep crystalline bedrock. Despite of similarities between Precambrian continental sites in Fennoscandia, South Africa and North America, where deep methane cycling has been studied, common physicochemical properties which could explain the variation in the amount of CH4 and presence or absence of CH4 cycling microbes were not found. However, based on their preferred carbon metabolism, methanogenic microbes appeared to have similar spatial distribution among the different sites.
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Affiliation(s)
| | - Lotta Purkamo
- VTT Technical Research Centre of Finland Espoo, Finland
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15
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Andrei AŞ, Robeson MS, Baricz A, Coman C, Muntean V, Ionescu A, Etiope G, Alexe M, Sicora CI, Podar M, Banciu HL. Contrasting taxonomic stratification of microbial communities in two hypersaline meromictic lakes. ISME JOURNAL 2015; 9:2642-56. [PMID: 25932617 DOI: 10.1038/ismej.2015.60] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Revised: 02/14/2015] [Accepted: 03/18/2015] [Indexed: 11/09/2022]
Abstract
Hypersaline meromictic lakes are extreme environments in which water stratification is associated with powerful physicochemical gradients and high salt concentrations. Furthermore, their physical stability coupled with vertical water column partitioning makes them important research model systems in microbial niche differentiation and biogeochemical cycling. Here, we compare the prokaryotic assemblages from Ursu and Fara Fund hypersaline meromictic lakes (Transylvanian Basin, Romania) in relation to their limnological factors and infer their role in elemental cycling by matching taxa to known taxon-specific biogeochemical functions. To assess the composition and structure of prokaryotic communities and the environmental factors that structure them, deep-coverage small subunit (SSU) ribosomal RNA (rDNA) amplicon sequencing, community domain-specific quantitative PCR and physicochemical analyses were performed on samples collected along depth profiles. The analyses showed that the lakes harbored multiple and diverse prokaryotic communities whose distribution mirrored the water stratification patterns. Ursu Lake was found to be dominated by Bacteria and to have a greater prokaryotic diversity than Fara Fund Lake that harbored an increased cell density and was populated mostly by Archaea within oxic strata. In spite of their contrasting diversity, the microbial populations indigenous to each lake pointed to similar physiological functions within carbon degradation and sulfate reduction. Furthermore, the taxonomy results coupled with methane detection and its stable C isotope composition indicated the presence of a yet-undescribed methanogenic group in the lakes' hypersaline monimolimnion. In addition, ultrasmall uncultivated archaeal lineages were detected in the chemocline of Fara Fund Lake, where the recently proposed Nanohaloarchaeota phylum was found to thrive.
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Affiliation(s)
- Adrian-Ştefan Andrei
- Institute for Interdisciplinary Research in Bio-Nano-Sciences, Molecular Biology Center, Babeş-Bolyai University, Cluj-Napoca, Romania.,Department of Molecular Biology and Biotechnology, Babeş-Bolyai University, Cluj-Napoca, Romania
| | - Michael S Robeson
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.,Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, CO, USA
| | - Andreea Baricz
- Department of Molecular Biology and Biotechnology, Babeş-Bolyai University, Cluj-Napoca, Romania.,National Institute of Research and Development for Biological Sciences (NIRDBS), Institute of Biological Research, Cluj-Napoca, Romania
| | - Cristian Coman
- Department of Molecular Biology and Biotechnology, Babeş-Bolyai University, Cluj-Napoca, Romania.,National Institute of Research and Development for Biological Sciences (NIRDBS), Institute of Biological Research, Cluj-Napoca, Romania
| | - Vasile Muntean
- Department of Molecular Biology and Biotechnology, Babeş-Bolyai University, Cluj-Napoca, Romania
| | - Artur Ionescu
- Faculty of Environmental Science and Engineering, Babeş-Bolyai University, Cluj-Napoca, Romania
| | - Giuseppe Etiope
- Faculty of Environmental Science and Engineering, Babeş-Bolyai University, Cluj-Napoca, Romania.,Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy
| | - Mircea Alexe
- Faculty of Geography, Babeş-Bolyai University, Cluj-Napoca, Romania
| | | | - Mircea Podar
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.,Department of Microbiology, University of Tennessee, Knoxville, TN, USA
| | - Horia Leonard Banciu
- Institute for Interdisciplinary Research in Bio-Nano-Sciences, Molecular Biology Center, Babeş-Bolyai University, Cluj-Napoca, Romania.,Department of Molecular Biology and Biotechnology, Babeş-Bolyai University, Cluj-Napoca, Romania
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16
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Sorokin DY, Abbas B, Geleijnse M, Pimenov NV, Sukhacheva MV, van Loosdrecht MCM. Methanogenesis at extremely haloalkaline conditions in the soda lakes of Kulunda Steppe (Altai, Russia). FEMS Microbiol Ecol 2015; 91:fiv016. [PMID: 25764464 DOI: 10.1093/femsec/fiv016] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/02/2015] [Indexed: 11/13/2022] Open
Abstract
Microbial methanogenesis at extreme conditions of saline alkaline soda lakes has, so far, been poorly investigated. Despite the obvious domination of sulfidogenesis as the therminal anaerobic process in the hypersaline soda lakes of Kulunda Steppe (Altai, southwestern Siberia), high concentrations of methane were detected in the anaerobic sediments. Potential activity measurements with different substrates gave results significantly deviating from what is commonly found in hypersaline habitats with neutral pH. In particular, not only a non-competitive methylotrophic pathway was active, but also lithotrophic and, in some cases, even acetate-dependent methanogenesis was found to be present in hypersaline soda lake sediments. All three pathways were functioning exclusively within the alkaline pH range between 8 and 10.5, while the salt concentration was the key factor influencing the activity. Methylotrophic and, to a lesser extent, lithotrophic methanogenesis were active up to soda-saturating conditions (4 M total Na(+)). Acetate-dependent methanogenesis was observed at salinities below 3 M total Na(+). Detection of methanogens in sediments using the mcrA gene as a functional marker demonstrated domination of methylotrophic genera Methanolobus and Methanosalsum and lithotrophic Methanocalculus. In a few cases, acetoclastic Methanosaeta was detected, as well as two deep lineage methanogens. Cultivation results corresponded well to the mcrA-based observations. Enrichments for natronophilic methylotrophic methanogens resulted in isolation of Methanolobus strains at moderate salinity, while at salt concentrations above 2 M Na(+) a novel member of the genus Methanosalsum was dominating. Enrichments with H2 or formate invariably resulted in domination of close relatives of Methanocalculus natronophilus. Enrichments with acetate at low salt concentration yielded two acetoclastic alkaliphilic Methanosaeta cultures, while at salinity above 1 M Na(+) syntrophic associations were apparently responsible for the observed acetate conversion to methane. Overall, the results indicated the presence of functionally structured and active methanogenic populations in Siberian hypersaline soda lakes.
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Affiliation(s)
- Dimitry Y Sorokin
- Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospect 60-let Octyabrya 7/2, 117811 Moscow, Russia Department of Biotechnology, Delft University of Technology, 2628 BC Delft, the Netherlands
| | - Ben Abbas
- Department of Biotechnology, Delft University of Technology, 2628 BC Delft, the Netherlands
| | - Mitchell Geleijnse
- Department of Biotechnology, Delft University of Technology, 2628 BC Delft, the Netherlands
| | - Nikolai V Pimenov
- Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospect 60-let Octyabrya 7/2, 117811 Moscow, Russia
| | - Marina V Sukhacheva
- Centre Bioengineering, Russian Academy of Sciences, Prospect 60-let Octyabrya 7/1, 117312 Moscow, Russia
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17
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García-Maldonado JQ, Bebout BM, Everroad RC, López-Cortés A. Evidence of novel phylogenetic lineages of methanogenic archaea from hypersaline microbial mats. MICROBIAL ECOLOGY 2015; 69:106-117. [PMID: 25108574 DOI: 10.1007/s00248-014-0473-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 07/25/2014] [Indexed: 06/03/2023]
Abstract
Methanogenesis in hypersaline and high-sulfate environments is typically dominated by methylotrophic methanogens because sulfate reduction is thermodynamically favored over hydrogenotrophic methanogenesis in these environments. We characterized the community composition of methanogenic archaea in both unmanipulated and incubated microbial mats from different hypersaline environments in Baja California Sur, Mexico. Clone libraries of methyl coenzyme-M reductase (mcrA) sequences and DGGE band patterns of 16S rRNA and mcrA sequences showed that the methanogen community in these microbial mats is dominated by methylotrophic methanogens of the genus Methanohalophilus. However, phylogenetic analyses of mcrA sequences from these mats also revealed two new lineages corresponding to putative hydrogenotrophic methanogens related with the strictly hydrogenotrophic order Methanomicrobiales. Stimulated methane production under decreased salinity and sulfate concentrations also suggested the presence of hydrogenotrophic methanogens in these samples. The relative abundance of mcrA gene and transcripts, estimated by SYBR green I qPCR assays, suggested the activity of different phylogenetic groups of methanogens, including the two novel clusters, in unmanipulated samples of hypersaline microbial mats. Using geochemical and molecular approaches, we show that substrate limitation and values of salinity and sulfate higher than 3 % and 25 mM (respectively) are potential environmental constraints for methanogenesis in these environments. Microcosm experiments with modifications of salinity and sulfate concentrations and TMA addition showed that upper salt and sulfate concentrations for occurrence of methylotrophic methanogenesis were 28 % and 263 mM, respectively. This study provides phylogenetic information about uncultivated and undescribed methanogenic archaea from hypersaline environments.
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Affiliation(s)
- José Q García-Maldonado
- Laboratorio de Geomicrobiología y Biotecnología, Centro de Investigaciones Biológicas del Noroeste, La Paz, BCS, Mexico
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18
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Trimethylamine and Organic Matter Additions Reverse Substrate Limitation Effects on the δ13C Values of Methane Produced in Hypersaline Microbial Mats. Appl Environ Microbiol 2014; 80:7316-23. [PMID: 25239903 DOI: 10.1128/aem.02641-14] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 09/12/2014] [Indexed: 11/20/2022] Open
Abstract
Methane production has been observed in a number of hypersaline environments, and it is generally thought that this methane is produced through the use of noncompetitive substrates, such as the methylamines, dimethylsulfide and methanol. Stable isotope measurements of the produced methane have also suggested that the methanogens are operating under conditions of substrate limitation. Here, substrate limitation in gypsum-hosted endoevaporite and soft-mat hypersaline environments was investigated by the addition of trimethylamine, a noncompetitive substrate for methanogenesis, and dried microbial mat, a source of natural organic matter. The δ(13)C values of the methane produced after amendments were compared to those in unamended control vials. At all hypersaline sites investigated, the δ(13)C values of the methane produced in the amended vials were statistically lower (by 10 to 71‰) than the unamended controls, supporting the hypothesis of substrate limitation at these sites. When substrates were added to the incubation vials, the methanogens within the vials fractionated carbon isotopes to a greater degree, resulting in the production of more (13)C-depleted methane. Trimethylamine-amended samples produced lower methane δ(13)C values than the mat-amended samples. This difference in the δ(13)C values between the two types of amendments could be due to differences in isotope fractionation associated with the dominant methane production pathway (or substrate used) within the vials, with trimethylamine being the main substrate used in the trimethylamine-amended vials. It is hypothesized that increased natural organic matter in the mat-amended vials would increase fermentation rates, leading to higher H2 concentrations and increased CO2/H2 methanogenesis.
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19
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Methane production potential and methanogenic archaea community dynamics along the Spartina alterniflora invasion chronosequence in a coastal salt marsh. Appl Microbiol Biotechnol 2013; 98:1817-29. [DOI: 10.1007/s00253-013-5104-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 07/02/2013] [Accepted: 07/04/2013] [Indexed: 11/30/2022]
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