Relationships between hydrosedimentary processes and occurrence of mercury-resistant bacteria (merA) in estuary mudflats (Seine, France).
The Seine estuary (France) is one of the world's macrotidal systems that is most contaminated with heavy metals. To study the mercury-resistant bacterial community in such an environment, we have developed a molecular tool, based on competitive PCR, enabling the quantification of Gram-negative merA gene abundance. The occurrence of the Gram-negative merA gene in relation with the topology (erosion/deposit periods) and the mercury contamination of three contrasted mudflats was investigated through a multidisciplinary approach and compared with a non-anthropized site (Authie, France). The higher abundance of the Gram-negative merA gene in the Seine estuary mudflats indicates a relationship between the degree of anthropization and the abundance of the merA gene in the mudflat sediments. In the Seine mudflats, the maxima of abundance are always located in fresh sediment deposits. Therefore, the abundance is closely related with the hydrosedimentary processes, which thus seem to be determining factors in the occurrence of the Gram-negative merA gene in the surface sediments of the Seine's mudflat.
Ramond
Jean-Baptiste
JB
Université de Rouen - CNRS UMR 6143, Morphodynamique Continentale et Côtière (M2C), Groupe de Microbiologie, 76821 Mont Saint Aignan Cedex, France.
Berthe
Thierry
T
Lafite
Robert
R
Deloffre
Julien
J
Ouddane
Baghdad
B
Petit
Fabienne
F
D004269:DNA, Bacterial / Q000032:analysis; D004784:Environmental Monitoring; D005602:France; D019015:Geologic Sediments; D008628:Mercury / Q000633:toxicity*; D009792:Oceans and Seas; D016133:Polymerase Chain Reaction; D045483:Rivers / Q000737:chemistry*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D053833:Wetlands
D004269:DNA, Bacterial; D014874:Water Pollutants, Chemical; D008628:Mercury