Transformation, localization, and biomolecular binding of Hg species at subcellular level in methylating and nonmethylating sulfate-reducing bacteria.
Microbial activity is recognized to play an important role on Hg methylation in aquatic ecosystems. However, the mechanism at the cellular level is still poorly understood. In this work subcellular partitioning and transformation of Hg species in two strains: Desulfovibrio sp. BerOc1 and Desulfovibrio desulfuricans G200 (which exhibit different Hg methylation potential) are studied as an approach to the elucidation of Hg methylation/demethylation processes. The incubation with isotopically labeled Hg species ((199)Hgi and Me(201)Hg) not only allows the determination of methylation and demethylation rates simultaneously, but also the comparison of the localization of the originally added and resulting species of such metabolic processes. A dissimilar Hg species distribution was observed. In general terms, monomethylmercury (MeHg) is preferentially localized in the extracellular fraction; meanwhile inorganic mercury (Hgi) is associated to the cells. The investigation of Hg binding biomolecules on the cytoplasmatic and extracellular fractions (size exclusion chromatography coupled to ICP-MS) revealed noticeable differences in the pattern corresponding to the Hg methylating and nonmethylating strains.
Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, Institut Pluridisciplinaire de Recherche sur l'Environnement et les Matériaux UMR 5254, CNRS Université de Pau et des Pays de l'Adour, 2 Avenue Pierre Angot, 64053 Pau, France. zoyne.pedrerozayas@univ-pau.fr
Zoyne
Z
Pedrero
Romain
R
Bridou
Sandra
S
Mounicou
Remy
R
Guyoneaud
Mathilde
M
Monperrus
David
D
Amouroux
D001711:Biotransformation; D002458:Cell Fractionation; D003593:Cytoplasm / Q000378:metabolism*; D003901:Desulfovibrio / Q000378:metabolism*; D005110:Extracellular Space / Q000378:metabolism*; D008628:Mercury / Q000378:metabolism*; D008745:Methylation; D008767:Methylmercury Compounds / Q000378:metabolism*
D008767:Methylmercury Compounds; D008628:Mercury