title: Impact of copper on the abundance and diversity of sulfate-reducing prokaryotes in two chilean marine sediments.
abstract: We studied the abundance and diversity of the sulfate-reducing prokaryotes (SRPs) in two 30-cm marine chilean sediment cores, one with a long-term exposure to copper-mining residues, the other being a non-exposed reference sediment. The abundance of SRPs was quantified by qPCR of the dissimilatory sulfite reductase gene β-subunit (dsrB) and showed that SRPs are sensitive to high copper concentrations, as the mean number of SRPs all along the contaminated sediment was two orders of magnitude lower than in the reference sediment. SRP diversity was analyzed by using the dsrB-sequences-based PCR-DGGE method and constructing gene libraries for dsrB-sequences. Surprisingly, the diversity was comparable in both sediments, with dsrB sequences belonging to Desulfobacteraceae, Syntrophobacteraceae, and Desulfobulbaceae, SRP families previously described in marine sediments, and to a deep branching dsrAB lineage. The hypothesis of the presence of horizontal transfer of copper resistance genes in the microbial population of the polluted sediment is discussed.
authors.affiliation: Faculté des Sciences, Université de Rouen, CNRS UMR 6143-M2C, Groupe de Microbiologie, Place Emile Blondel, 76821 Mont Saint Aignan Cedex, France. ludovic.besaury@etu.univ-rouen.fr
authors.forename: Ludovic
authors.initials: L
authors.lastname: Besaury
authors.forename: Baghdad
authors.initials: B
authors.lastname: Ouddane
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Pavissich
authors.forename: Carole
authors.initials: C
authors.lastname: Dubrulle-Brunaud
authors.forename: Bernardo
authors.initials: B
authors.lastname: González
authors.forename: Laurent
authors.initials: L
authors.lastname: Quillet
mesh_terms: D001483:Base Sequence; D044822:Biodiversity; D002677:Chile; D003300:Copper / Q000633:toxicity*; D014644:Genetic Variation; D019015:Geologic Sediments / Q000737:chemistry / Q000382:microbiology*; D008969:Molecular Sequence Data; D011387:Prokaryotic Cells / Q000145:classification / Q000187:drug effects; D012623:Seawater / Q000737:chemistry / Q000382:microbiology; D016999:Sulfur-Reducing Bacteria / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D003300:Copper