Methanogens and Iron-Reducing Bacteria: the Overlooked Members of Mercury-Methylating Microbial Communities in Boreal Lakes

• Andrea G. Bravo ^[5] ; Sari Peura ^[1] ; Moritz Buck ^[2] ; Omneya Ahmed ^[2] ; Alejandro Mateos-Rivera ^[2] ; Sonia Herrero Ortega ^[2] ; Jeffra K. Schaefer ^[3] ; Sylvain Bouchet ^[4] ; Julie Tolu ^[4] ; Erik Björn ^[4] ; Stefan Bertilsson ^[2]
  1. [1] Swedish University of Agricultural Sciences

     Swedish University of Agricultural Sciences

     Uppsala domkyrkoförs., Suecia

     
  2. [2] Uppsala University

     Uppsala University

     Uppsala domkyrkoförs., Suecia

     
  3. [3] Rutgers University

     Rutgers University

     City of New Brunswick, Estados Unidos

     
  4. [4] Umeå University

     Umeå University

     Suecia

     
  5. [5] aDepartment of Ecology and Genetics, Limnology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden; bDepartment of Marine Biology and Oceanography, Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas, Barcelona, Catalonia, Spain

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• Localización: Applied and Environmental Microbiology, ISSN 0099-2240, Vol. 84, Nº 23, 2018
• Idioma: inglés
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  • Despite the global awareness that mercury, and methylmercury in particular, is a neurotoxin to which millions of people continue to be exposed, there are sizable gaps in the understanding of the processes and organisms involved in methylmercury formation in aquatic ecosystems. In the present study, we shed light on the diversity of the microorganisms responsible for methylmercury formation in boreal lake sediments. All the microorganisms identified are associated with the processing of organic matter in aquatic systems. Moreover, our results show that the well-known mercury-methylating sulfate-reducing bacteria constituted only a minor portion of the potential mercury methylators. In contrast, methanogens and iron-reducing bacteria were important contributors to methylmercury formation, highlighting their role in mercury cycling in the environment.