Anaerobic oxidation of methane and associated microbiome in anoxic water of Northwestern Siberian lakes

• Published in: Science of The Total Environment
• Main Authors: Cabrol, Léa, Thalasso, Frédéric, Gandois, Laure, Sepulveda-Jauregui, Armando, Martinez-Cruz, Karla, Teisserenc, Roman, Tananaev, Nikita, Tveit, Alexander, Svenning, Mette, Barret, Maialen
• Other Authors: Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Centro de Investigacion y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), University of Magallanes (UMAG), Melnikov Permafrost Institute, Siberian Branch of the Russian Academy of Sciences (SB RAS), The Arctic University of Norway Tromsø, Norway (UiT), MAEDI (Ministère des Affaires Etrangères et duDéveloppement International) and MENESR (Ministère de l'Éducationnationale, de l'Enseignement supérieur et de la Recherche) French ministries and CONICYT (Comisión Nacional de Investigación Científica yTecnológica) (Chile) forfinancial support through the ERANet-LAC jointprogramMETHANOBASE (ELAC2014_DCC-009), European Project: ELAC2014 DCC-0092,Methanobase
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDE.MCG]Environmental Sciences/Global Changes; [SDE.IE]Environmental Sciences/Environmental Engineering; [SDV.BIO]Life Sciences [q-bio]/Biotechnology; [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology; permafrost
• Online Access: https://amu.hal.science/hal-03151740; https://amu.hal.science/hal-03151740/document; https://amu.hal.science/hal-03151740/file/23-Cabrol_2020_AOM%20siberian%20lakes.pdf; https://doi.org/10.1016/j.scitotenv.2020.139588

International audience Arctic lakes emit methane (CH 4) to the atmosphere. The magnitude of this flux could increase with permafrost thaw but might also be mitigated by microbial CH 4 oxidation. Methane oxidation in oxic water has been extensively studied, while the contribution of anaerobic oxidation of methane (AOM) to CH 4 mitigation is not fully understood. We have investigated four Northern Siberian stratified lakes in an area of discontinuous permafrost nearby Igarka, Russia. Analyses of CH 4 concentrations in the water column demonstrated that 60 to 100% of upward diffusing CH 4 was oxidized in the anoxic layers of the four lakes. A combination of pmoA and mcrA gene qPCR and 16S rRNA gene metabarcoding showed that the same taxa, all within Methylomonadaceae and including the predominant genus Methylobacter as well as Crenothrix, could be the major methane-oxidizing bacteria (MOB) in the anoxic water of the four lakes. Correlation between Methylomonadaceae and OTUs within Methylotenera, Geothrix and Geobacter genera indicated that AOM might occur in an interaction between MOB, denitrifiers and iron-cycling partners. We conclude that MOB within Methylomonadaceae could have a crucial impact on CH 4 cycling in these Siberian Arctic lakes by mitigating the majority of produced CH 4 before it leaves the anoxic zone. This finding emphasizes the importance of AOM by Methylomonadaceae and extends our knowledge about CH 4 cycle in lakes, a crucial component of the global CH 4 cycle.