Culture-dependent comparison of microbial diversity in deep granitic groundwater from two sites considered for a Swedish final repository of spent nuclear fuel

Hallbeck, Lotta; Pedersen, Karsten

doi:10.1111/j.1574-6941.2011.01281.x

Cited by 50 publications

(57 citation statements)

References 22 publications

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“…In contrast, VLPs were below detection in the O 2 :N 2 FCC, which attests that the metabolic activity of micro-organisms in this system was likely inactivated by the O 2 addition to a level at which lytic phage activity was arrested. Taken together, is seems safe to conclude that bacteriophages controlled the number of cells in this experiment, keeping it at a cell density within the range observed in deep Fennoscandian groundwater, that is, between 5 Â 10 3 and 1 Â 10 6 cells ml À 1 Hallbeck and Pedersen, 2012).…”

Section: Cell Density Control By Bacteriophagesmentioning

confidence: 99%

Metabolic activity of subterranean microbial communities in deep granitic groundwater supplemented with methane and H2

Pedersen¹

2012

The ISME Journal

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It was previously concluded that opposing gradients of sulphate and methane, observations of 16S ribosomal DNA sequences displaying great similarity to those of anaerobic methane-oxidizing Archaea and a peak in sulphide concentration in groundwater from a depth of 250-350 m in Olkiluoto, Finland, indicated proper conditions for methane oxidation with sulphate. In the present research, pressure-resistant, gas-tight circulating systems were constructed to enable the investigation of attached and unattached anaerobic microbial populations from a depth of 327 m in Olkiluoto under in situ pressure (2.4 MPa), diversity, dissolved gas and chemistry conditions. Three parallel flow cell cabinets were configured to allow observation of the influence on microbial metabolic activity of 11 mM methane, 11 mM methane plus 10 mM H 2 or 2.1 mM O 2 plus 7.9 mM N 2 (that is, air). The concentrations of these gases and of organic acids and carbon, sulphur chemistry, pH and E h , ATP, numbers of cultivable micro-organisms, and total numbers of cells and bacteriophages were subsequently recorded under batch conditions for 105 days. The system containing H 2 and methane displayed microbial reduction of 0.7 mM sulphate to sulphide, whereas the system containing only methane resulted in 0.2 mM reduced sulphate. The system containing added air became inhibited and displayed no signs of microbial activity. Added H 2 and methane induced increasing numbers of lysogenic bacteriophages per cell. It appears likely that a microbial anaerobic methane-oxidizing process coupled to acetate formation and sulphate reduction may be ongoing in aquifers at a depth of 250-350 m in Olkiluoto. The ISME Journal (2013) 7, 839-849; doi:10.1038/ismej.2012.144; published online 13 December 2012Subject category: microbial ecology and functional diversity of natural habitats

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Section: Cell Density Control By Bacteriophagesmentioning

confidence: 99%

Metabolic activity of subterranean microbial communities in deep granitic groundwater supplemented with methane and H2

Pedersen¹

2012

The ISME Journal

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“…Dispersal limitation, therefore, may obscure the detection of in situ biogeochemical processes except at sufficiently closely spaced sampling locations relative to recharge and discharge. Diverse microbial communities within these formations (Jain et al, 1997; Haveman et al, 1999; Sahl et al, 2008; Itävaara et al, 2011; Thompson et al, 2011; Hallbeck and Pedersen, 2012; Nyyssönen et al, 2012, 2014) display activities for nitrate, iron and sulfate reduction (Pedersen, 1996; Jain et al, 1997; Haveman et al, 1999; Hallbeck and Pedersen, 2012). Our aim is to understand how communities in fractured granite form and what these findings mean in a broader context of a study site.…”

Section: Introductionmentioning

confidence: 99%

Local and Regional Diversity Reveals Dispersal Limitation and Drift as Drivers for Groundwater Bacterial Communities from a Fractured Granite Formation

et al. 2016

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Microorganisms found in terrestrial subsurface environments make up a large proportion of the Earth’s biomass. Biogeochemical cycles catalyzed by subsurface microbes have the potential to influence the speciation and transport of radionuclides managed in geological repositories. To gain insight on factors that constrain microbial processes within a formation with restricted groundwater flow we performed a meta-community analysis on groundwater collected from multiple discrete fractures underlying the Chalk River Laboratories site (located in Ontario, Canada). Bacterial taxa were numerically dominant in the groundwater. Although these were mainly uncultured, the closest cultivated representatives were from the phenotypically diverse Betaproteobacteria, Deltaproteobacteria, Bacteroidetes, Actinobacteria, Nitrospirae, and Firmicutes. Hundreds of taxa were identified but only a few were found in abundance (>1%) across all assemblages. The remainder of the taxa were low abundance. Within an ecological framework of selection, dispersal and drift, the local and regional diversity revealed fewer taxa within each assemblage relative to the meta-community, but the taxa that were present were more related than predicted by chance. The combination of dispersion at one phylogenetic depth and clustering at another phylogenetic depth suggest both niche (dispersion) and filtering (clustering) as drivers of local assembly. Distance decay of similarity reveals apparent biogeography of 1.5 km. Beta diversity revealed greater influence of selection at shallow sampling locations while the influences of dispersal limitation and randomness were greater at deeper sampling locations. Although selection has shaped each assemblage, the spatial scale of groundwater sampling favored detection of neutral processes over selective processes. Dispersal limitation between assemblages combined with local selection means the meta-community is subject to drift, and therefore, likely reflects the differential historical events that have influenced the current bacterial composition. Categorizing the study site into smaller regions of interest of more closely spaced fractures, or of potentially hydraulically connected fractures, might improve the resolution of an analysis to reveal environmental influences that have shaped these bacterial communities.

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“…The determination of cultivable micro-organisms and ATP also agreed well when analysed . Many different phenotypes of micro-organisms have been found via cultivation (Hallbeck, 2008(Hallbeck, , 2012, including fungi (Ekendahl, 2003;Reitner, 2005). The influence of viruses on microbial processes has been identified as an important factor to include in model studies.…”

Section: High-level Waste Repositoriesmentioning

confidence: 99%

Analysis of mineralogical and deformation-induced transformations of Nizhnekansky Massif rocks to estimate their retention capacity in geological disposal and isolation of radioactive waste

Петров¹,

Poluektov²,

Hammer³

et al. 2015

gzh

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JT03354141Complete document available on OLIS in its original format This document and any map included herein are without prejudice to the status of or sovereignty over any territory, to the delimitation of international frontiers and boundaries and to the name of any territory, city or area. . Since then, there have been major developments in a number of national geological disposal programmes and significant experience has been obtained in preparing and reviewing cases for the operational and long-term safety of proposed and operating geological repositories. Especially, three national programmes are now, or will shortly be, at the stage of licence application for a deep geological repository for the disposal of spent nuclear fuel or high-level and other long-lived radioactive waste.Thus, the purpose of this Symposium, "The Safety Case for Deep Geological Disposal of Radioactive Waste: 2013 State of the Art", was to assess the practice, understanding and roles of the safety case, as applied internationally at all stages of repository development, including the interplay of technical, regulatory and societal issues, as they have developed since 2007.The Symposium was organised and hosted by the Nuclear Energy Agency (NEA) of the Organisation for Economic Co-operation and Development (OECD), and co-sponsored by the EC and the IAEA.The 2013 Symposium attracted 168 participants from 65 organisations and 17 countries and international bodies.The Symposium was chaired by Klaus-Jürgen Röhlig, who is also the Chair of the NEA Integration Group for the Safety Case (IGSC). The planning and implementation of the symposium were supported by the efforts of staff of the NEA and of the programme committee.This synopsis was drafted by Trevor Sumerling (Safety Assessment Management Ltd, UK), finalised under the direction of the Chair and Gloria Kwong of the NEA and approved by the programme committee. Deep Geological Repositories (1999). Since then the concept has been elaborated on in NEA documents describing the nature and purpose of safety cases , 2013a and has been the basis of NEA/IGSC collaborative projects and EU projects (EC, 2011). The concept has been taken up in international safety standards as promulgated by the IAEA (2006, 2011) and recently in ICRP recommendations on the application of the system of radiological protection to geological disposal (ICRP, 2013).Meanwhile, the concept has been developed practically and applied within many national radioactive waste disposal programmes and also taken up in some national regulatory guides. The NEA has used the concept as a guide in several international peer reviews of national repository programmes and safety documentation. In Europe, the EU Directive 2011/70/Euratom (EU, 2011) establishes a framework to ensure responsible and safe management of spent fuel and radioactive waste by member states that, inter alia, requires a decision-making process based on safety evidence and arguments that mirrors the safety case concept. Aims of the symposiumThe purpose of thi...

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Culture-dependent comparison of microbial diversity in deep granitic groundwater from two sites considered for a Swedish final repository of spent nuclear fuel

Cited by 50 publications

References 22 publications

Metabolic activity of subterranean microbial communities in deep granitic groundwater supplemented with methane and H2

Metabolic activity of subterranean microbial communities in deep granitic groundwater supplemented with methane and H2

Local and Regional Diversity Reveals Dispersal Limitation and Drift as Drivers for Groundwater Bacterial Communities from a Fractured Granite Formation

Analysis of mineralogical and deformation-induced transformations of Nizhnekansky Massif rocks to estimate their retention capacity in geological disposal and isolation of radioactive waste

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