title: Reconstructing a hydrogen-driven microbial metabolic network in Opalinus Clay rock.
abstract: The Opalinus Clay formation will host geological nuclear waste repositories in Switzerland. It is expected that gas pressure will build-up due to hydrogen production from steel corrosion, jeopardizing the integrity of the engineered barriers. In an in situ experiment located in the Mont Terri Underground Rock Laboratory, we demonstrate that hydrogen is consumed by microorganisms, fuelling a microbial community. Metagenomic binning and metaproteomic analysis of this deep subsurface community reveals a carbon cycle driven by autotrophic hydrogen oxidizers belonging to novel genera. Necromass is then processed by fermenters, followed by complete oxidation to carbon dioxide by heterotrophic sulfate-reducing bacteria, which closes the cycle. This microbial metabolic web can be integrated in the design of geological repositories to reduce pressure build-up. This study shows that Opalinus Clay harbours the potential for chemolithoautotrophic-based system, and provides a model of microbial carbon cycle in deep subsurface environments where hydrogen and sulfate are present.
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne, Environmental Microbiology Laboratory, Station 6, Lausanne CH-1015, Switzerland.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Bagnoud
authors.affiliation: Oak Ridge National Laboratory, Chemical Sciences Division, Oak Ridge, Tennessee 37831, USA.
authors.forename: Karuna
authors.initials: K
authors.lastname: Chourey
authors.affiliation: Oak Ridge National Laboratory, Chemical Sciences Division, Oak Ridge, Tennessee 37831, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Hettich
authors.affiliation: Bioinformatics Infrastructure for Life Sciences (BILS), Stockholm 171 65, Sweden.|KTH Royal Institute of Technology, Science for Life Laboratory, School of Biotechnology, Division of Gene Technology, Stockholm 171 65, Sweden.
authors.forename: Ino
authors.identifier: 0000-0001-5427-4750
authors.initials: I
authors.lastname: de Bruijn
authors.affiliation: KTH Royal Institute of Technology, Science for Life Laboratory, School of Biotechnology, Division of Gene Technology, Stockholm 171 65, Sweden.
authors.forename: Anders F
authors.identifier: 0000-0002-3627-6899
authors.initials: AF
authors.lastname: Andersson
authors.affiliation: Nagra, Wettingen CH-5430, Switzerland.
authors.forename: Olivier X
authors.initials: OX
authors.lastname: Leupin
authors.affiliation: Nagra, Wettingen CH-5430, Switzerland.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schwyn
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne, Environmental Microbiology Laboratory, Station 6, Lausanne CH-1015, Switzerland.
authors.forename: Rizlan
authors.initials: R
authors.lastname: Bernier-Latmani
mesh_terms: D000538:Aluminum Silicates; D052818:Autotrophic Processes; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism; D057486:Carbon Cycle; D000077215:Clay; D017753:Ecosystem; D005843:Geography; D052836:Heterotrophic Processes; D006859:Hydrogen / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D056186:Metagenomics / Q000379:methods*; D059013:Microbial Consortia; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D011850:Radioactive Waste; D012988:Soil Microbiology; D013557:Switzerland
chemical_list: D000538:Aluminum Silicates; D012336:RNA, Ribosomal, 16S; D011850:Radioactive Waste; D006859:Hydrogen; D000077215:Clay