Hydrogen Utilization Potential in Subsurface Sediments
- Subsurface microbial communities undertake many terminal electron-accepting processes, often simultaneously. Using a tritium-based assay, we measured the potential hydrogen oxidation catalyzed by hydrogenase enzymes in several subsurface sedimentary environments (Lake Van, Barents Sea, Equatorial Pacific, and Gulf of Mexico) with different predominant electron-acceptors. Hydrogenases constitute a diverse family of enzymes expressed by microorganisms that utilize molecular hydrogen as a metabolic substrate, product, or intermediate. The assay reveals the potential for utilizing molecular hydrogen and allows qualitative detection of microbial activity irrespective of the predominant electron-accepting process. Because the method only requires samples frozen immediately after recovery, the assay can be used for identifying microbial activity in subsurface ecosystems without the need to preserve live material. We measured potential hydrogen oxidation rates in all samples from multiple depths at several sites that collectively span a wideSubsurface microbial communities undertake many terminal electron-accepting processes, often simultaneously. Using a tritium-based assay, we measured the potential hydrogen oxidation catalyzed by hydrogenase enzymes in several subsurface sedimentary environments (Lake Van, Barents Sea, Equatorial Pacific, and Gulf of Mexico) with different predominant electron-acceptors. Hydrogenases constitute a diverse family of enzymes expressed by microorganisms that utilize molecular hydrogen as a metabolic substrate, product, or intermediate. The assay reveals the potential for utilizing molecular hydrogen and allows qualitative detection of microbial activity irrespective of the predominant electron-accepting process. Because the method only requires samples frozen immediately after recovery, the assay can be used for identifying microbial activity in subsurface ecosystems without the need to preserve live material. We measured potential hydrogen oxidation rates in all samples from multiple depths at several sites that collectively span a wide range of environmental conditions and biogeochemical zones. Potential activity normalized to total cell abundance ranges over five orders of magnitude and varies, dependent upon the predominant terminal electron acceptor. Lowest per-cell potential rates characterize the zone of nitrate reduction and highest per-cell potential rates occur in the methanogenic zone. Possible reasons for this relationship to predominant electron acceptor include (i) increasing importance of fermentation in successively deeper biogeochemical zones and (ii) adaptation of H(2)ases to successively higher concentrations of H-2 in successively deeper zones.…
Author details: | Rishi Ram AdhikariORCiDGND, Clemens Glombitza, Julia C. Nickel, Chloe H. Anderson, Ann G. Dunlea, Arthur J. Spivack, Richard W. Murray, Jens KallmeyerORCiDGND |
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DOI: | https://doi.org/10.3389/fmicb.2016.00008 |
ISSN: | 1664-302X |
Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/26858697 |
Title of parent work (English): | Frontiers in microbiology |
Publisher: | Frontiers Research Foundation |
Place of publishing: | Lausanne |
Publication type: | Article |
Language: | English |
Year of first publication: | 2016 |
Publication year: | 2016 |
Release date: | 2020/03/22 |
Tag: | Barents Sea; Equatorial Pacific; Gulf of Mexico; Lake Van; deep biosphere; hydrogenase; microbial activity; tritium assay |
Volume: | 7 |
Number of pages: | 16 |
Funding institution: | Federal Ministry of Education and Research (BMBF), Germany through the Forschungsverbundvorhaben GeoEn [03G0671A/B/C]; LUNDIN Petroleum Norway; German Science Foundation (DFG) through the ICDP Priority Program [SPP 1006, KA2293/4-1]; Marie-Curie Individual Fellowship [327675]; NSF Division of Ocean Sciences [0939564]; National Science Foundation; Biological Oceanography Program of the US National Science Foundation [OCE-0752336] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
Peer review: | Referiert |
Institution name at the time of the publication: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Erd- und Umweltwissenschaften |