Geochemical transition zone powering microbial growth in subsurface sediments
| Autor: | Desiree L. Roerdink, Christa Schleper, Jennifer F. Biddle, Steffen Leth Jørgensen, Ingunn H. Thorseth, Sophie S. Abby, Rui Zhao, José M Mogollón |
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| Přispěvatelé: | University of Bergen (UiB), Universiteit Leiden [Leiden], Génomique et Évolution des Microorganismes (TIMC-IMAG-GEM ), Techniques de l'Ingénierie Médicale et de la Complexité - Informatique, Mathématiques et Applications Grenoble - UMR 5525 (TIMC-IMAG), VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Université de Vienne, universite de Vienne, Delaware State University (DSU) |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Geologic Sediments
Biogeochemical cycle Nitrogen Oceans and Seas Population microbial in situ growth energy availability Bacterial growth Bacterial Physiological Phenomena Microbiology 03 medical and health sciences Earth Atmospheric and Planetary Sciences [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry Molecular Biology/Genomics [q-bio.GN] Ammonium Compounds Transition zone nitrogen cycle deep biosphere 14. Life underwater education Nitrogen cycle ComputingMilieux_MISCELLANEOUS 030304 developmental biology 0303 health sciences education.field_of_study Nitrates Multidisciplinary Bacteria biology Arctic Regions 030306 microbiology [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE] Biodiversity Biological Sciences biology.organism_classification [SDV.BIBS]Life Sciences [q-bio]/Quantitative Methods [q-bio.QM] 13. Climate action Anammox Environmental chemistry Physical Sciences Scalindua Environmental science anammox Genome Bacterial Mixotroph |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America Proceedings of the National Academy of Sciences of the United States of America, National Academy of Sciences, 2020, pp.202005917. ⟨10.1073/pnas.2005917117⟩ PNAS, 117(51), 32617-32626 32617-32626 |
| ISSN: | 0027-8424 1091-6490 |
| DOI: | 10.1073/pnas.2005917117⟩ |
| Popis: | Significance The marine sedimentary subsurface is a vast and inhospitable ecosystem, often described as a place where microbes “race to their death,” as microbial cells are buried and available energy is severely diminished with increasing depth/age. By combining a variety of biogeochemical and molecular methods to describe the energetics and genetics of the bacteria specialized in anaerobic ammonium oxidation, we show that despite prolonged exposure to highly unfavorable conditions for tens of thousands of years, these bacteria exhibit remarkable net population growth when reaching their niche: the nitrate–ammonium transition zone. This common, yet understudied, geochemical transition zone represents an oasis in the sedimentary energetic desert, and the growth it supports is of major importance for the global nitrogen cycle. No other environment hosts as many microbial cells as the marine sedimentary biosphere. While the majority of these cells are expected to be alive, they are speculated to be persisting in a state of maintenance without net growth due to extreme starvation. Here, we report evidence for in situ growth of anaerobic ammonium-oxidizing (anammox) bacteria in ∼80,000-y-old subsurface sediments from the Arctic Mid-Ocean Ridge. The growth is confined to the nitrate–ammonium transition zone (NATZ), a widespread geochemical transition zone where most of the upward ammonium flux from deep anoxic sediments is being consumed. In this zone the anammox bacteria abundances, assessed by quantification of marker genes, consistently displayed a four order of magnitude increase relative to adjacent layers in four cores. This subsurface cell increase coincides with a markedly higher power supply driven mainly by intensified anammox reaction rates, thereby providing a quantitative link between microbial proliferation and energy availability. The reconstructed draft genome of the dominant anammox bacterium showed an index of replication (iRep) of 1.32, suggesting that 32% of this population was actively replicating. The genome belongs to a Scalindua species which we name Candidatus Scalindua sediminis, so far exclusively found in marine sediments. It has the capacity to utilize urea and cyanate and a mixotrophic lifestyle. Our results demonstrate that specific microbial groups are not only able to survive unfavorable conditions over geological timescales, but can proliferate in situ when encountering ideal conditions with significant consequences for biogeochemical nitrogen cycling. |
| Databáze: | OpenAIRE |
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