Bacterial periphytic communities related to mercury methylation within aquatic plant roots from a temperate freshwater lake (South-Western France)
2017
Gentès, Sophie | Taupiac, Julie | Colin, Yannick | André, Jean-Marc | Guyoneaud, Remy | Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux (IPREM) ; Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS) | Environnements et Paléoenvironnements OCéaniques (EPOC) ; Observatoire aquitain des sciences de l'univers (OASU) ; Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE) ; Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) | Interactions Arbres-Microorganismes (IAM) ; Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL) | Ecole Nationale Supérieure de Cognitique (ENSC) ; Institut Polytechnique de Bordeaux | Laboratoire de l'intégration, du matériau au système (IMS) ; Université Sciences et Technologies - Bordeaux 1 (UB)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS) | COGNITIQUE ; Laboratoire de l'intégration, du matériau au système (IMS) ; Université Sciences et Technologies - Bordeaux 1 (UB)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS) | Conseil Général des Landes; DIRECT project (Les microorganismes sulfato-réducteurs colonisant les racines de macrophytes aquatiques: DIversité et Risques liés à la méthylation du mErcure et son transfert vers la Chaîne Trophique)
cited By 0
显示更多 [+] 显示较少 [-]International audience
显示更多 [+] 显示较少 [-]英语. Macrophyte floating roots are considered as hotspots for methylmercury (MeHg) production in aquatic ecosystems through microbial activity. Nevertheless, very little is known about periphyton bacterial communities and mercury (Hg) methylators in such ecological niches. The ability to methylate inorganic Hg is broadly distributed among prokaryotes; however, sulfate-reducers have been reported to be the most important MeHg producers in macrophyte floating roots. In the present work, the periphyton bacterial communities colonizing Ludwigia sp. floating roots were investigated through molecular methods. Among the 244 clones investigated, anaerobic microorganisms associated with the sulfur biogeochemical cycle were identified. Notably, members of the sulfur-oxidizing prokaryotes and the anoxygenic, purple non-sulfur bacteria (Rhodobacteraceae, Comamonadaceae, Rhodocyclaceae, Hyphomicrobiaceae) and the sulfate reducers (Desulfobacteraceae, Syntrophobacteraceae, and Desulfobulbaceae) were detected. In addition, 15 sulfate-reducing strains related to the Desulfovibrionaceae family were isolated and their Hg-methylation capacity was tested using a biosensor. The overall results confirmed that Hg methylation is a strain-specific process since the four strains identified as new Hg-methylators were closely related to non-methylating isolates. This study highlights the potential involvement of periphytic bacteria in Hg methylation when favorable environmental conditions are present in such ecological micro-niches.
显示更多 [+] 显示较少 [-]