Mercury methylation by a microbial community from sediments of the Adour Estuary (Bay of Biscay, France)

• Published in: Environmental pollution (1987) 2008-12, Vol.156 (3), p.951-958
• Main Authors: Duran, R., Ranchou-Peyruse, M., Menuet, V., Monperrus, M., Bareille, G., Goñi, M.S., Salvado, J.C., Amouroux, D., Guyoneaud, R., Donard, O.F.X., Caumette, P.
• Format: Article
• Language: English
• Subjects: aerobic conditions; anaerobic conditions; Anaerobiosis; Applied sciences; bacteria; Bacterial diversity; Biodegradation, Environmental; biogeochemistry; Biological and physicochemical properties of pollutants. Interaction in the soil; Brackish; Earth Sciences; Earth, ocean, space; Ecology - methods; Engineering and environment geology. Geothermics; environmental factors; Environmental Monitoring - methods; estuaries; Exact sciences and technology; France; Fresh Water - microbiology; Geochemistry; Geologic Sediments - microbiology; heavy metals; Mercury; Mercury - chemistry; Mercury - pharmacology; Methylation; Methylmercury; Methylmercury Compounds - chemistry; microorganisms; Organotin Compounds - metabolism; Pollution; Pollution, environment geology; population structure; restriction fragment length polymorphism; Sciences of the Universe; Seawater; sediments; Soil and sediments pollution; Soil Pollutants - chemistry; Soil Pollutants - pharmacology; spatial variation; strains; Sulfur-Reducing Bacteria - isolation & purification; Sulfur-Reducing Bacteria - metabolism; Sulphate-reducing bacteria; T-RFLP; Trialkyltin Compounds - metabolism; Water Pollutants - metabolism; Wetlands
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2008.05.007

In order to study the influence of microorganisms on the mercury biogeochemistry, the metal content and the structure of microbial communities were determined in sediments from stations along the Adour Estuary. The comparison of the bacterial communities and their distribution in function of the environmental parameters by Canonical Correspondence Analysis (CCA) revealed the influence of metals on the bacterial communities structure. Sediments where the bacterial communities are mostly influenced by methylmercury were incubated in slurries with or without mercury, under oxic and anoxic conditions. Methylmercury production was detected in the anoxic biotic slurries with a net methylation yield of 0.3% after 24 h. CCA based on T-RFLP profiles revealed the impact of mercury addition on the bacterial communities structure. In addition, 17 bacterial strains, mainly sulphate-reducing bacteria involved in mercury methylation, were isolated and identified. Role of oxic/anoxic cycles and microbial activities on the methylmercury formation in Adour (France) estuarine sediments.