1
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Butterworth SJ, Barton F, Lloyd JR. Extremophilic microbial metabolism and radioactive waste disposal. Extremophiles 2023; 27:27. [PMID: 37839067 PMCID: PMC10577106 DOI: 10.1007/s00792-023-01312-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 09/12/2023] [Indexed: 10/17/2023]
Abstract
Decades of nuclear activities have left a legacy of hazardous radioactive waste, which must be isolated from the biosphere for over 100,000 years. The preferred option for safe waste disposal is a deep subsurface geological disposal facility (GDF). Due to the very long geological timescales required, and the complexity of materials to be disposed of (including a wide range of nutrients and electron donors/acceptors) microbial activity will likely play a pivotal role in the safe operation of these mega-facilities. A GDF environment provides many metabolic challenges to microbes that may inhabit the facility, including high temperature, pressure, radiation, alkalinity, and salinity, depending on the specific disposal concept employed. However, as our understanding of the boundaries of life is continuously challenged and expanded by the discovery of novel extremophiles in Earth's most inhospitable environments, it is becoming clear that microorganisms must be considered in GDF safety cases to ensure accurate predictions of long-term performance. This review explores extremophilic adaptations and how this knowledge can be applied to challenge our current assumptions on microbial activity in GDF environments. We conclude that regardless of concept, a GDF will consist of multiple extremes and it is of high importance to understand the limits of polyextremophiles under realistic environmental conditions.
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Affiliation(s)
- Sarah Jane Butterworth
- Department of Earth and Environmental Sciences, Research Centre for Radwaste Disposal and Williamson Research Centre, The University of Manchester, Manchester, UK
| | - Franky Barton
- Department of Earth and Environmental Sciences, Research Centre for Radwaste Disposal and Williamson Research Centre, The University of Manchester, Manchester, UK.
| | - Jonathan Richard Lloyd
- Department of Earth and Environmental Sciences, Research Centre for Radwaste Disposal and Williamson Research Centre, The University of Manchester, Manchester, UK.
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2
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Lopez-Fernandez M, Westmeijer G, Turner S, Broman E, Ståhle M, Bertilsson S, Dopson M. Thiobacillus as a key player for biofilm formation in oligotrophic groundwaters of the Fennoscandian Shield. NPJ Biofilms Microbiomes 2023; 9:41. [PMID: 37349512 DOI: 10.1038/s41522-023-00408-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 06/09/2023] [Indexed: 06/24/2023] Open
Abstract
Biofilm formation is a common adaptation for microbes in energy-limited conditions such as those prevalent in the vast deep terrestrial biosphere. However, due to the low biomass and the inaccessible nature of subsurface groundwaters, the microbial populations and genes involved in its formation are understudied. Here, a flow-cell system was designed to investigate biofilm formation under in situ conditions in two groundwaters of contrasting age and geochemistry at the Äspö Hard Rock Laboratory, Sweden. Metatranscriptomes showed Thiobacillus, Sideroxydans, and Desulforegula to be abundant and together accounted for 31% of the transcripts in the biofilm communities. Differential expression analysis highlighted Thiobacillus to have a principal role in biofilm formation in these oligotrophic groundwaters by being involved in relevant processes such as the formation of extracellular matrix, quorum sensing, and cell motility. The findings revealed an active biofilm community with sulfur cycling as a prominent mode of energy conservation in the deep biosphere.
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Affiliation(s)
- Margarita Lopez-Fernandez
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 392 31, Kalmar, Sweden.
- Department of Microbiology, Faculty of Sciences, University of Granada, Avenida Fuentenueva s/n, 18071, Granada, Spain.
| | - George Westmeijer
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 392 31, Kalmar, Sweden
| | - Stephanie Turner
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 392 31, Kalmar, Sweden
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Box 7026, 75007, Uppsala, Sweden
| | - Elias Broman
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 392 31, Kalmar, Sweden
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Svante Arrhenius väg 20 A, 106 91, Stockholm, Sweden
| | - Magnus Ståhle
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 392 31, Kalmar, Sweden
| | - Stefan Bertilsson
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, SE75007, Uppsala, Sweden
| | - Mark Dopson
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 392 31, Kalmar, Sweden
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3
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Soares A, Edwards A, An D, Bagnoud A, Bradley J, Barnhart E, Bomberg M, Budwill K, Caffrey SM, Fields M, Gralnick J, Kadnikov V, Momper L, Osburn M, Mu A, Moreau JW, Moser D, Purkamo L, Rassner SM, Sheik CS, Sherwood Lollar B, Toner BM, Voordouw G, Wouters K, Mitchell AC. A global perspective on bacterial diversity in the terrestrial deep subsurface. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001172. [PMID: 36748549 PMCID: PMC9993121 DOI: 10.1099/mic.0.001172] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 03/07/2022] [Indexed: 01/19/2023]
Abstract
While recent efforts to catalogue Earth's microbial diversity have focused upon surface and marine habitats, 12-20 % of Earth's biomass is suggested to exist in the terrestrial deep subsurface, compared to ~1.8 % in the deep subseafloor. Metagenomic studies of the terrestrial deep subsurface have yielded a trove of divergent and functionally important microbiomes from a range of localities. However, a wider perspective of microbial diversity and its relationship to environmental conditions within the terrestrial deep subsurface is still required. Our meta-analysis reveals that terrestrial deep subsurface microbiota are dominated by Betaproteobacteria, Gammaproteobacteria and Firmicutes, probably as a function of the diverse metabolic strategies of these taxa. Evidence was also found for a common small consortium of prevalent Betaproteobacteria and Gammaproteobacteria operational taxonomic units across the localities. This implies a core terrestrial deep subsurface community, irrespective of aquifer lithology, depth and other variables, that may play an important role in colonizing and sustaining microbial habitats in the deep terrestrial subsurface. An in silico contamination-aware approach to analysing this dataset underscores the importance of downstream methods for assuring that robust conclusions can be reached from deep subsurface-derived sequencing data. Understanding the global panorama of microbial diversity and ecological dynamics in the deep terrestrial subsurface provides a first step towards understanding the role of microbes in global subsurface element and nutrient cycling.
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Affiliation(s)
- A. Soares
- Department of Geography and Earth Sciences (DGES), Aberystwyth University (AU), Aberystwyth, UK
- Institute of Biology, Environmental and Rural Sciences (IBERS), AU, Aberystwyth, UK
- Department of Plant and Microbial Biology, University of Minnesota, Minneapolis, MN, USA
- Present address: Group for Aquatic Microbial Ecology (GAME), University of Duisburg-Essen, Campus Essen - Environmental Microbiology and Biotechnology, Universitätsstr. 5, 45141 Essen, Germany
| | - A. Edwards
- Institute of Biology, Environmental and Rural Sciences (IBERS), AU, Aberystwyth, UK
- Interdisciplinary Centre for Environmental Microbiology (iCEM), AU, Aberystwyth, UK
| | - D. An
- Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - A. Bagnoud
- Institut de Génie Thermique (IGT), Haute École d'Ingénierie et de Gestion du Canton de Vaud (HEIG-VD), Yverdon-les-Bains, Switzerland
| | - J. Bradley
- School of Geography, Queen Mary University of London, London, UK
| | - E. Barnhart
- U.S. Geological Survey (USGS), USA, Reston, VA, USA
- Center for Biofilm Engineering (CBE), Montana State University, Bozeman, MT, USA
| | - M. Bomberg
- VTT Technical Research Centre of Finland, Finland
| | | | | | - M. Fields
- Center for Biofilm Engineering (CBE), Montana State University, Bozeman, MT, USA
- Department of Microbiology & Immunology, MSU, Bozeman, MT, USA
| | - J. Gralnick
- Department of Plant and Microbial Biology, University of Minnesota, Minneapolis, MN, USA
| | - V. Kadnikov
- Institute of Bioengineering, Research Center of Biotechnology, Russian Academy of Sciences, Russia
| | - L. Momper
- Department of Earth, Atmospheric and Planetary Sciences (DEAPS), The Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - M. Osburn
- Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL, USA
| | - A. Mu
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
- Doherty Applied Microbial Genomics, Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, University of Melbourne, Melbourne, Australia
| | - J. W. Moreau
- School of Earth Sciences, The University of Melbourne, Parkville, Australia
| | - D. Moser
- Division of Hydrologic Sciences, Desert Research Institute (DRI), Las Vegas, NV, USA
| | - L. Purkamo
- VTT Technical Research Centre of Finland, Finland
- School of Earth and Environmental Sciences (SEES), University of St. Andrews, St. Andrews, UK
- Geological Survey of Finland (GTK), Finland
| | - S. M. Rassner
- Department of Geography and Earth Sciences (DGES), Aberystwyth University (AU), Aberystwyth, UK
- Interdisciplinary Centre for Environmental Microbiology (iCEM), AU, Aberystwyth, UK
| | - C. S. Sheik
- Large Lakes Observatory, University of Minnesota, Duluth, MN, USA
| | | | - B. M. Toner
- Department of Soil, Water & Climate, University of Minnesota, Minneapolis/Saint Paul, MN, USA
| | - G. Voordouw
- Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - K. Wouters
- Institute for Environment, Health and Safety (EHS), Belgian Nuclear Research Centre SCK•CEN, Mol, Belgium
| | - A. C. Mitchell
- Department of Geography and Earth Sciences (DGES), Aberystwyth University (AU), Aberystwyth, UK
- Interdisciplinary Centre for Environmental Microbiology (iCEM), AU, Aberystwyth, UK
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4
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Osterholz H, Turner S, Alakangas LJ, Tullborg EL, Dittmar T, Kalinowski BE, Dopson M. Terrigenous dissolved organic matter persists in the energy-limited deep groundwaters of the Fennoscandian Shield. Nat Commun 2022; 13:4837. [PMID: 35977924 PMCID: PMC9385861 DOI: 10.1038/s41467-022-32457-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 08/01/2022] [Indexed: 11/09/2022] Open
Abstract
The deep terrestrial biosphere encompasses the life below the photosynthesis-fueled surface that perseveres in typically nutrient and energy depleted anoxic groundwaters. The composition and cycling of this vast dissolved organic matter (DOM) reservoir relevant to the global carbon cycle remains to be deciphered. Here we show that recent Baltic Sea-influenced to ancient pre-Holocene saline Fennoscandian Shield deep bedrock fracture waters carried DOM with a strong terrigenous signature and varying contributions from abiotic and biotic processes. Removal of easily degraded carbon at the surface-to-groundwater transition and corresponding microbial community assembly processes likely resulted in the highly similar DOM signatures across the notably different water types that selected for a core microbiome. In combination with the aliphatic character, depleted δ13C signatures in DOM indicated recent microbial production in the oldest, saline groundwater. Our study revealed the persistence of terrestrially-sourced carbon in severely energy limited deep continental groundwaters supporting deep microbial life.
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Affiliation(s)
- Helena Osterholz
- Marine Chemistry, Leibniz Institute for Baltic Sea Research Warnemünde, Rostock, Germany.
| | - Stephanie Turner
- Ecology and Evolution in Microbial model Systems (EEMiS), Linnaeus University, Kalmar, Sweden.,Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Linda J Alakangas
- Ecology and Evolution in Microbial model Systems (EEMiS), Linnaeus University, Kalmar, Sweden.,Swedish Nuclear Fuel and Waste Management Company, Äspö Hard Rock Laboratory, Oskarshamn, Sweden
| | | | - Thorsten Dittmar
- Marine Geochemistry, Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University, Oldenburg, Germany.,Helmholtz Institute for Functional Marine Biodiversity, Carl von Ossietzky University, Oldenburg, Germany
| | - Birgitta E Kalinowski
- Swedish Nuclear Fuel and Waste Management Company, Äspö Hard Rock Laboratory, Oskarshamn, Sweden
| | - Mark Dopson
- Ecology and Evolution in Microbial model Systems (EEMiS), Linnaeus University, Kalmar, Sweden
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5
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Nuppunen-Puputti M, Kietäväinen R, Raulio M, Soro A, Purkamo L, Kukkonen I, Bomberg M. Epilithic Microbial Community Functionality in Deep Oligotrophic Continental Bedrock. Front Microbiol 2022; 13:826048. [PMID: 35300483 PMCID: PMC8921683 DOI: 10.3389/fmicb.2022.826048] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/12/2022] [Indexed: 01/03/2023] Open
Abstract
The deep terrestrial biosphere hosts vast sessile rock surface communities and biofilms, but thus far, mostly planktic communities have been studied. We enriched deep subsurface microbial communities on mica schist in microcosms containing bedrock groundwater from the depth of 500 m from Outokumpu, Finland. The biofilms were visualized using scanning electron microscopy, revealing numerous different microbial cell morphologies and attachment strategies on the mica schist surface, e.g., bacteria with outer membrane vesicle-like structures, hair-like extracellular extensions, and long tubular cell structures expanding over hundreds of micrometers over mica schist surfaces. Bacterial communities were analyzed with amplicon sequencing showing that Pseudomonas, Desulfosporosinus, Hydrogenophaga, and Brevundimonas genera dominated communities after 8–40 months of incubation. A total of 21 metagenome assembled genomes from sessile rock surface metagenomes identified genes involved in biofilm formation, as well as a wide variety of metabolic traits indicating a high degree of environmental adaptivity to oligotrophic environment and potential for shifting between multiple energy or carbon sources. In addition, we detected ubiquitous organic carbon oxidation and capacity for arsenate and selenate reduction within our rocky MAGs. Our results agree with the previously suggested interaction between the deep subsurface microbial communities and the rock surfaces, and that this interaction could be crucial for sustaining life in the harsh anoxic and oligotrophic deep subsurface of crystalline bedrock environment.
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Affiliation(s)
| | | | - Mari Raulio
- European Chemicals Agency (ECHA), Helsinki, Finland
| | - Aino Soro
- VTT Technical Research Centre of Finland Ltd., Espoo, Finland
| | | | - Ilmo Kukkonen
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Malin Bomberg
- VTT Technical Research Centre of Finland Ltd., Espoo, Finland
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6
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Westmeijer G, Mehrshad M, Turner S, Alakangas L, Sachpazidou V, Bunse C, Pinhassi J, Ketzer M, Åström M, Bertilsson S, Dopson M. Connectivity of Fennoscandian Shield terrestrial deep biosphere microbiomes with surface communities. Commun Biol 2022; 5:37. [PMID: 35017653 PMCID: PMC8752596 DOI: 10.1038/s42003-021-02980-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 12/15/2021] [Indexed: 12/20/2022] Open
Abstract
The deep biosphere is an energy constrained ecosystem yet fosters diverse microbial communities that are key in biogeochemical cycling. Whether microbial communities in deep biosphere groundwaters are shaped by infiltration of allochthonous surface microorganisms or the evolution of autochthonous species remains unresolved. In this study, 16S rRNA gene amplicon analyses showed that few groups of surface microbes infiltrated deep biosphere groundwaters at the Äspö Hard Rock Laboratory, Sweden, but that such populations constituted up to 49% of the microbial abundance. The dominant persisting phyla included Patescibacteria, Proteobacteria, and Epsilonbacteraeota. Despite the hydrological connection of the Baltic Sea with the studied groundwaters, infiltrating microbes predominantly originated from deep soil groundwater. Most deep biosphere groundwater populations lacked surface representatives, suggesting that they have evolved from ancient autochthonous populations. We propose that deep biosphere groundwater communities in the Fennoscandian Shield consist of selected infiltrated and indigenous populations adapted to the prevailing conditions. Westmeijer et al. employ high-throughput sequencing to investigate the connection between deep biosphere groundwaters and surface microbial communities. They suggest that the microbial communities of deep biosphere groundwaters in the Fennoscandian Shield are mostly comprised of autochthonous species, rather than migratory surface representatives.
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Affiliation(s)
- George Westmeijer
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 39 231, Kalmar, Sweden.
| | - Maliheh Mehrshad
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, P.O. Box 7050, 75 007, Uppsala, Sweden
| | - Stephanie Turner
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 39 231, Kalmar, Sweden
| | - Linda Alakangas
- Swedish Nuclear Fuel and Waste Management Co (SKB), 57 229, Oskarshamn, Sweden
| | - Varvara Sachpazidou
- Department of Biology and Environmental Sciences, Linnaeus University, 39 231, Kalmar, Sweden
| | - Carina Bunse
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 39 231, Kalmar, Sweden.,Helmholtz-Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), 26129, Oldenburg, Germany
| | - Jarone Pinhassi
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 39 231, Kalmar, Sweden
| | - Marcelo Ketzer
- Department of Biology and Environmental Sciences, Linnaeus University, 39 231, Kalmar, Sweden
| | - Mats Åström
- Department of Biology and Environmental Sciences, Linnaeus University, 39 231, Kalmar, Sweden
| | - Stefan Bertilsson
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, P.O. Box 7050, 75 007, Uppsala, Sweden
| | - Mark Dopson
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 39 231, Kalmar, Sweden
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7
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Bourrain M, Suzuki MT, Calvez A, West NJ, Lions J, Lebaron P. In-depth prospection of Avène Thermal Spring Water reveals an uncommon and stable microbial community. J Eur Acad Dermatol Venereol 2021; 34 Suppl 5:8-14. [PMID: 32870559 DOI: 10.1111/jdv.16599] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/24/2020] [Accepted: 04/30/2020] [Indexed: 01/04/2023]
Abstract
BACKGROUND Avène Thermal Spring Water (TSW) exhibits therapeutic properties in the treatment of skin pathologies. Arising from a dolomitic aquifer system, its physico-chemical properties are well-established and its bacteriological quality regularly monitored. The microbiota of this aquifer have been characterized. OBJECTIVES We aimed to describe the structure of the bacterial community inhabiting the deep aquifer and to examine its dynamics over time. METHODS The Avène TSW was collected at the catchment point and filtered through 0.1 µm pore size filters. The sampling was carried out every 3 months to generate a 4-year time series. The DNA extracted from filters was analysed using high-throughput 16S rRNA gene amplicon sequencing, and the microorganisms and their contribution were characterized by the taxonomic assignment of sequence variants generated from each sample. RESULTS Bacteria were distributed into 39 phyla. Nitrospirae and Proteobacteria were the most prevalent, accounting for 38% and 23% of the total community on average, respectively. A stable pattern was observed throughout the study. A few bacterial species were always detected, forming a core community of likely chemolithoautotrophic organisms which might use energy sources and nutrients produced from water-bedrock interactions. Most of the species were distantly related to organisms described to date. CONCLUSIONS Avène TSW provided by the deep aquifer system harbours a unique microbial community, shaped by the physico-chemical characteristics of the deep environment. Its remarkable stability over time has revealed a high level of confinement of the water resource.
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Affiliation(s)
- M Bourrain
- Pierre Fabre Dermo-Cosmétique R&D Center, Toulouse, France
| | - M T Suzuki
- Sorbonne Université, CNRS, Laboratoire de Biodiversité et Biotechnologies Microbiennes, LBBM, Observatoire Océanologique, Banyuls-sur-mer, France
| | - A Calvez
- Pierre Fabre Dermo-Cosmétique R&D Center, Toulouse, France
| | - N J West
- Sorbonne Université, CNRS, Observatoire Océanologique de Banyuls, Banyuls-sur-mer, France
| | - J Lions
- Pierre Fabre Dermo-Cosmétique R&D Center, Toulouse, France
| | - P Lebaron
- Sorbonne Université, CNRS, Laboratoire de Biodiversité et Biotechnologies Microbiennes, LBBM, Observatoire Océanologique, Banyuls-sur-mer, France
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8
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The Fennoscandian Shield deep terrestrial virosphere suggests slow motion 'boom and burst' cycles. Commun Biol 2021; 4:307. [PMID: 33686191 PMCID: PMC7940616 DOI: 10.1038/s42003-021-01810-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 02/08/2021] [Indexed: 12/22/2022] Open
Abstract
The deep biosphere contains members from all three domains of life along with viruses. Here we investigate the deep terrestrial virosphere by sequencing community nucleic acids from three groundwaters of contrasting chemistries, origins, and ages. These viromes constitute a highly unique community compared to other environmental viromes and sequenced viral isolates. Viral host prediction suggests that many of the viruses are associated with Firmicutes and Patescibacteria, a superphylum lacking previously described active viruses. RNA transcript-based activity implies viral predation in the shallower marine water-fed groundwater, while the deeper and more oligotrophic waters appear to be in ‘metabolic standby’. Viral encoded antibiotic production and resistance systems suggest competition and antagonistic interactions. The data demonstrate a viral community with a wide range of predicted hosts that mediates nutrient recycling to support a higher microbial turnover than previously anticipated. This suggests the presence of ‘kill-the-winner’ oscillations creating slow motion ‘boom and burst’ cycles. Karin Holmfeldt et al. sequence metagenomes and metatranscriptomes of viruses in deep groundwaters down to 448 m below the surface. The results reveal ecological dynamics of viruses including slow motion ‘boom and burst’ cycles and a ‘kill the winner’ model potentially driven by viral predation.
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9
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Tan G, Zhou R, Zhang W, Hu Y, Ruan Z, Li J, Zhang C, Shen D, Peng N, Liang Y, Zhao S. Detection of Viable and Total Bacterial Community in the Pit Mud of Chinese Strong-Flavor Liquor Using Propidium Monoazide Combined With Quantitative PCR and 16S rRNA Gene Sequencing. Front Microbiol 2020; 11:896. [PMID: 32528426 PMCID: PMC7264162 DOI: 10.3389/fmicb.2020.00896] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 04/16/2020] [Indexed: 12/23/2022] Open
Abstract
Microbiota in the pit mud (PM) plays a crucial role in the production of Chinese strong-flavor liquor (CSFL), the most popular distilled liquor in China. However, previous studies used total microbes, instead of viable ones, for the characterization of the microbial community in this environment. In this study, we used propidium monoazide (PMA) combined with quantitative polymerase chain reaction (qPCR) and 16S rRNA gene sequencing to verify the effect of non-viablee bacteria on the characterization of PM bacteria. After PMA concentration optimization, 50 μM PMA was chosen to pretreat 5 and 20 years PMs. The qPCR results showed that there were 50.78 and 71.84% of non-viable bacteria in the 5-year PM and 20-year PM, respectively. Both copy numbers of total bacteria and viable bacteria were significantly higher in 20-year PM than those in 5-year PM. Nevertheless, in terms of bacterial diversity and composition analyses at the operational taxonomic unit (OTU), phylum, class, and genus levels, 16S rRNA gene sequencing results displayed no significant differences between total bacteria and viable bacteria in both PM types. In conclusion, it is necessary for non-viable bacteria to be considered in determining absolute biomass of bacteria in PM, but not necessary in the analysis of diversity and composition of PM bacteria. To the best of our knowledge, our study is the first attempt to analyze viable bacteria in the PM of CSFL and provides useful information on how to accurately characterize a microbial community in a PM environment.
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Affiliation(s)
- Guangxun Tan
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.,Zhijiang Liquor Industry Co., Ltd., Zhijiang, China
| | - Rui Zhou
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Wenqian Zhang
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Yuanliang Hu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.,Hubei Key Laboratory of Edible Wild Plants Conservation and Utilization, College of Life Sciences, Hubei Normal University, Huangshi, China
| | - Zhiyong Ruan
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Microbial Resources (Ministry of Agriculture, China), Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jing Li
- Zhijiang Liquor Industry Co., Ltd., Zhijiang, China
| | - Changyi Zhang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, IL, United States
| | - Dengjin Shen
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Nan Peng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Yunxiang Liang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Shumiao Zhao
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
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10
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Statistical Analysis of Community RNA Transcripts between Organic Carbon and Geogas-Fed Continental Deep Biosphere Groundwaters. mBio 2019; 10:mBio.01470-19. [PMID: 31409677 PMCID: PMC6692508 DOI: 10.1128/mbio.01470-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Despite being separated from the photosynthesis-driven surface by both distance and time, the deep biosphere is an important driver for the earth’s carbon and energy cycles. However, due to the difficulties in gaining access and low cell numbers, robust statistical omics studies have not been carried out, and this limits the conclusions that can be drawn. This study benchmarks the use of two separate sampling systems and demonstrates that they provide statistically similar RNA transcript profiles, importantly validating several previously published studies. The generated data are analyzed to identify statistically valid differences in active microbial community members and metabolic processes. The results highlight contrasting taxa and growth strategies in the modern marine waters that are influenced by recent infiltration of Baltic Sea water versus the hydrogen- and carbon dioxide-fed, extremely oligotrophic, thoroughly mixed water. Life in water-filled bedrock fissures in the continental deep biosphere is broadly constrained by energy and nutrient availability. Although these communities are alive, robust studies comparing active populations and metabolic processes across deep aquifers are lacking. This study analyzed three oligotrophic Fennoscandian Shield groundwaters, two “modern marine” waters that are replenished with organic carbon from the Baltic Sea and are likely less than 20 years old (171.3 and 415.4 m below sea level) and an extremely oligotrophic “thoroughly mixed” water (448.8 m below sea level) of unknown age that is composed of very old saline and marine waters. Cells were captured either using a sampling device that rapidly fixed RNA under in situ conditions or by filtering flowing groundwater over an extended period before fixation. Comparison of metatranscriptomes between the methods showed statistically similar transcript profiles for the respective water types, and they were analyzed as biological replicates. Study of the small subunit (SSU) rRNA confirmed active populations from all three domains of life, with many potentially novel unclassified populations present. Statistically supported differences between communities included heterotrophic sulfate-reducing bacteria in the modern marine water at 171.3 m below sea level that has a higher organic carbon content than do largely autotrophic populations in the H2- and CO2-fed thoroughly mixed water. While this modern marine water had signatures of methanogenesis, syntrophic populations were predominantly in the thoroughly mixed water. The study provides a first statistical evaluation of differences in the active microbial communities in groundwaters differentially fed by organic carbon or “geogases.”
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Christel S, Yu C, Wu X, Josefsson S, Lillhonga T, Högfors-Rönnholm E, Sohlenius G, Åström ME, Dopson M. Comparison of boreal acid sulfate soil microbial communities in oxidative and reductive environments. Res Microbiol 2019; 170:288-295. [PMID: 31279086 DOI: 10.1016/j.resmic.2019.06.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 04/30/2019] [Accepted: 06/26/2019] [Indexed: 10/26/2022]
Abstract
Due to land uplift after the last ice age, previously stable Baltic Sea sulfidic sediments are becoming dry land. When these sediments are drained, the sulfide minerals are exposed to air and can release large amounts of metals and acid into the environment. This can cause severe ecological damage such as fish kills in rivers feeding the northern Baltic Sea. In this study, five sites were investigated for the occurrence of acid sulfate soils and their geochemistry and microbiology was identified. The pH and soil chemistry identified three of the areas as having classical acid sulfate soil characteristics and culture independent identification of 16S rRNA genes identified populations related to acidophilic bacteria capable of catalyzing sulfidic mineral dissolution, including species likely adapted to low temperature. These results were compared to an acid sulfate soil area that had been flooded for ten years and showed that the previously oxidized sulfidic materials had an increased pH compared to the unremediated oxidized layers. In addition, the microbiology of the flooded soil had changed such that alkalinity producing ferric and sulfate reducing reactions had likely occurred. This suggested that flooding of acid sulfate soils mitigates their environmental impact.
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Affiliation(s)
- Stephan Christel
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, SE-39182 Kalmar, Sweden.
| | - Changxun Yu
- Department of Biology and Environmental Science, Linnaeus University, SE-39182 Kalmar, Sweden
| | - Xiaofen Wu
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, SE-39182 Kalmar, Sweden
| | - Sarah Josefsson
- Geological Survey of Sweden, Box 670, 751 28 Uppsala, Sweden
| | - Tom Lillhonga
- Research and Development, Novia University of Applied Sciences, FI-65200, Vaasa, Finland
| | - Eva Högfors-Rönnholm
- Research and Development, Novia University of Applied Sciences, FI-65200, Vaasa, Finland
| | | | - Mats E Åström
- Department of Biology and Environmental Science, Linnaeus University, SE-39182 Kalmar, Sweden
| | - Mark Dopson
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, SE-39182 Kalmar, Sweden
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Lopez-Fernandez M, Åström M, Bertilsson S, Dopson M. Depth and Dissolved Organic Carbon Shape Microbial Communities in Surface Influenced but Not Ancient Saline Terrestrial Aquifers. Front Microbiol 2018; 9:2880. [PMID: 30538690 PMCID: PMC6277548 DOI: 10.3389/fmicb.2018.02880] [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: 09/11/2018] [Accepted: 11/09/2018] [Indexed: 12/31/2022] Open
Abstract
The continental deep biosphere is suggested to contain a substantial fraction of the earth's total biomass and microorganisms inhabiting this environment likely have a substantial impact on biogeochemical cycles. However, the deep microbial community is still largely unknown and can be influenced by parameters such as temperature, pressure, water residence times, and chemistry of the waters. In this study, 21 boreholes representing a range of deep continental groundwaters from the Äspö Hard Rock Laboratory were subjected to high-throughput 16S rRNA gene sequencing to characterize how the different water types influence the microbial communities. Geochemical parameters showed the stability of the waters and allowed their classification into three groups. These were (i) waters influenced by infiltration from the Baltic Sea with a "modern marine (MM)" signature, (ii) a "thoroughly mixed (TM)" water containing groundwaters of several origins, and (iii) deep "old saline (OS)" waters. Decreasing microbial cell numbers positively correlated with depth. In addition, there was a stronger positive correlation between increased cell numbers and dissolved organic carbon for the MM compared to the OS waters. This supported that the MM waters depend on organic carbon infiltration from the Baltic Sea while the ancient saline waters were fed by "geogases" such as carbon dioxide and hydrogen. The 16S rRNA gene relative abundance of the studied groundwaters revealed different microbial community compositions. Interestingly, the TM water showed the highest dissimilarity compared to the other two water types, potentially due to the several contrasting water types contributing to this groundwater. The main identified microbial phyla in the groundwaters were Gammaproteobacteria, unclassified sequences, Campylobacterota (formerly Epsilonproteobacteria), Patescibacteria, Deltaproteobacteria, and Alphaproteobacteria. Many of these taxa are suggested to mediate ferric iron and nitrate reduction, especially in the MM waters. This indicated that nitrate reduction may be a neglected but important process in the deep continental biosphere. In addition to the high number of unclassified sequences, almost 50% of the identified phyla were archaeal or bacterial candidate phyla. The percentage of unknown and candidate phyla increased with depth, pointing to the importance and necessity of further studies to characterize deep biosphere microbial populations.
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Affiliation(s)
| | - Mats Åström
- Department of Biology and Environmental Science, Linnaeus University, Kalmar, Sweden
| | - Stefan Bertilsson
- Limnology and Science for Life Laboratory, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Mark Dopson
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar, Sweden
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Metatranscriptomes Reveal That All Three Domains of Life Are Active but Are Dominated by Bacteria in the Fennoscandian Crystalline Granitic Continental Deep Biosphere. mBio 2018; 9:mBio.01792-18. [PMID: 30459191 PMCID: PMC6247080 DOI: 10.1128/mbio.01792-18] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A newly designed sampling apparatus was used to fix RNA under in situ conditions in the deep continental biosphere and benchmarks a strategy for deep biosphere metatranscriptomic sequencing. This apparatus enabled the identification of active community members and the processes they carry out in this extremely oligotrophic environment. This work presents for the first time evidence of eukaryotic, archaeal, and bacterial activity in two deep subsurface crystalline rock groundwaters from the Äspö Hard Rock Laboratory with different depths and geochemical characteristics. The findings highlight differences between organic carbon-fed shallow communities and carbon dioxide- and hydrogen-fed old saline waters. In addition, the data reveal a large portion of uncharacterized microorganisms, as well as the important role of candidate phyla in the deep biosphere, but also the disparity in microbial diversity when using standard microbial 16S rRNA gene amplification versus the large unknown portion of the community identified with unbiased metatranscriptomes. The continental subsurface is suggested to contain a significant part of the earth’s total biomass. However, due to the difficulty of sampling, the deep subsurface is still one of the least understood ecosystems. Therefore, microorganisms inhabiting this environment might profoundly influence the global nutrient and energy cycles. In this study, in situ fixed RNA transcripts from two deep continental groundwaters from the Äspö Hard Rock Laboratory (a Baltic Sea-influenced water with a residence time of <20 years, defined as “modern marine,” and an “old saline” groundwater with a residence time of thousands of years) were subjected to metatranscriptome sequencing. Although small subunit (SSU) rRNA gene and mRNA transcripts aligned to all three domains of life, supporting activity within these community subsets, the data also suggested that the groundwaters were dominated by bacteria. Many of the SSU rRNA transcripts grouped within newly described candidate phyla or could not be mapped to known branches on the tree of life, suggesting that a large portion of the active biota in the deep biosphere remains unexplored. Despite the extremely oligotrophic conditions, mRNA transcripts revealed a diverse range of metabolic strategies that were carried out by multiple taxa in the modern marine water that is fed by organic carbon from the surface. In contrast, the carbon dioxide- and hydrogen-fed old saline water with a residence time of thousands of years predominantly showed the potential to carry out translation. This suggested these cells were active, but waiting until an energy source episodically becomes available.
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Stott M, Lueders T. Editorial: Deep life, kia ora! FEMS Microbiol Ecol 2018; 94:5101342. [DOI: 10.1093/femsec/fiy176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 09/03/2018] [Indexed: 11/12/2022] Open
Affiliation(s)
- Matthew Stott
- School of Biological Sciences, University of Canterbury, Christchurch, 8140, New Zealand
| | - Tillmann Lueders
- Institute of Groundwater Ecology, Helmholtz Zentrum München, 85764 Neuherberg, Germany
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