In-depth characterization of denitrifier communities across different soil ecosystems in the tundra

• Published in: Environmental Microbiome
• Main Authors: Pessi, Igor, Viitamäki, Sirja, Virkkala, Anna-Maria, Eronen-Rasimus, Eeva, Delmont, Tom, Marushchak, Maija, Luoto, Miska, Hultman, Jenni
• Other Authors: Finnish Environment Institute (SYKE), Génomique métabolique (UMR 8030), Genoscope - Centre national de séquençage Evry (GENOSCOPE), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université d'Évry-Val-d'Essonne (UEVE)-Centre National de la Recherche Scientifique (CNRS), Global Oceans Systems Ecology & Evolution - Tara Oceans (GOSEE), Université de Perpignan Via Domitia (UPVD)-École Pratique des Hautes Études (EPHE), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Aix Marseille Université (AMU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université d'Évry-Val-d'Essonne (UEVE)-Université de Toulon (UTLN)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 )-Institut de Recherche pour le Développement (IRD France-Nord )-Ecole Normale Supérieure Paris-Saclay (ENS Paris Saclay)-European Molecular Biology Laboratory (EMBL)-NANTES UNIVERSITÉ - École Centrale de Nantes (Nantes Univ - ECN), Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Université australe du Chili, Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Natural Resources Institute Finland (LUKE)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: [SDV]Life Sciences [q-bio]; [SDV.BBM]Life Sciences [q-bio]/Biochemistry; Molecular Biology; [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry; Molecular Biology/Genomics [q-bio.GN]; Northern Finland; Tundra
• Online Access: https://cea.hal.science/cea-04425162; https://doi.org/10.1186/s40793-022-00424-2

International audience Abstract Background In contrast to earlier assumptions, there is now mounting evidence for the role of tundra soils as important sources of the greenhouse gas nitrous oxide (N 2 O). However, the microorganisms involved in the cycling of N 2 O in this system remain largely uncharacterized. Since tundra soils are variable sources and sinks of N 2 O, we aimed at investigating differences in community structure across different soil ecosystems in the tundra. Results We analysed 1.4 Tb of metagenomic data from soils in northern Finland covering a range of ecosystems from dry upland soils to water-logged fens and obtained 796 manually binned and curated metagenome-assembled genomes (MAGs). We then searched for MAGs harbouring genes involved in denitrification, an important process driving N 2 O emissions. Communities of potential denitrifiers were dominated by microorganisms with truncated denitrification pathways (i.e., lacking one or more denitrification genes) and differed across soil ecosystems. Upland soils showed a strong N 2 O sink potential and were dominated by members of the Alphaproteobacteria such as Bradyrhizobium and Reyranella . Fens, which had in general net-zero N 2 O fluxes, had a high abundance of poorly characterized taxa affiliated with the Chloroflexota lineage Ellin6529 and the Acidobacteriota subdivision Gp23. Conclusions By coupling an in-depth characterization of microbial communities with in situ measurements of N 2 O fluxes, our results suggest that the observed spatial patterns of N 2 O fluxes in the tundra are related to differences in the composition of denitrifier communities.