A field campaign was organized in June 2021 to collect soil, porewater and atmospheric samples. From these samples, genomic and lipidomic data were extracted and the concentration of reactive dissolved gases as well as major nutrients and inorganic constituents was determined. This enabled to identify the major microbial taxa present in the wetland as well as the major microbial processes. In particular, an increase of archaeal taxa, dominated by Ca. Bathyarchaeota, was observed with depth. Combined analysis of metagenomic data and compound specific isotopic composition of microbial membrane lipids evidenced, for the first time in continental settings, the autotrophic metabolism of Ca. Bathyarchaeaota. In the second year of the project, soil samples were incubated in flow-through reactors with either carbon dioxide (CO2) or methane (CH4) as the major carbon source. Genomic and lipidomic data are under interpretation but preliminary data of the analysis of CO2, CH4 and major inorganic compounds revealed substantial anaerobic oxidation of CH4, potentially related to sulfate reduction.
Related internship supervised :
-Pierre Lebreton, undergraduate internship, 12/04/2021 - 18/06/2021, dissolved gases measurements in flow-through reactors by membrane inlet mass spectrometry (MIMS).
-Karine Lemaître, graduate internship, 28/02/2022 – 27/08/2022, methane dynamics in continental wetlands
Communications in international conferences :
-Coffinet S., Dufresne A., Quaiser A., Longuevergne L., Hinrichs K.-U. Laverman A.M. Identification of microbial methane sources and sinks in an aquifer-fed continental wetland with a multi-omics approach. Goldschmidt, virtual conference, July 2021.
-Coffinet S., Dufresne A., Quaiser A., Hinrichs K.-U. Laverman A. M., Identification of microbial methane sources and sinks in an aquifer-fed continental wetland with a multi-omics approach, EGU General Assembly, Vienne, Austria, April 2022.
Communications in national events :
-Coffinet S., Dufresne A., Quaiser A., Longuevergne L., Hinrichs K.-U. Laverman A. M., Identification of microbial methane sources and sinks in an aquifer-fed continental wetland with a multi-omics approach, 10th symposium of the French association in microbial ecology (AFEM), virtual edition, November 2021.
-Coffinet S., Dufresne A., Quaiser A., Longuevergne L., Hinrichs K.-U. Laverman A.M. Identification of microbial methane sources and sinks in an aquifer-fed continental wetland with a multi-omics approach. OZCAR Summer School, Barcelonnette, France, July 2021.
-Lemaître K., Coffinet S., Chatton E., Dufresne A., Quaiser A., Labasque T., Laverman A. Methane dynamics in continental wetlands, 5th meeting of the French Researchers in Organic Geochemistry (FROG), Rennes, France, July 2022.
Invited seminars:
-Hinrichs’ lab, MARUM, Bremen University, Germany (March 2022).
