title: Relationships between bacterial energetic metabolism, mercury methylation potential, and hgcA/hgcB gene expression in Desulfovibrio dechloroacetivorans BerOc1.
abstract: The proteins encoded by the hgcA and hgcB genes are currently the only ones known to be involved in the mercury methylation by anaerobic microorganisms. However, no studies have been published to determine the relationships between their expression level and the net/gross methylmercury production. This study aimed to decipher the effect of growth conditions on methylmercury production and the relationships between hgcA and hgcB expression levels and net methylation. Desulfovibrio dechloroacetivorans strain BerOc1 was grown under sulfidogenic conditions with different carbon sources and electron donors as well as under fumarate respiration. A good correlation was found between the biomass production and the methylmercury production when the strain was grown under sulfate-reducing conditions. Methylmercury production was much higher under fumarate respiration when no sulfide was produced. During exponential growth, hgcA and hgcB gene expression levels were only slightly higher in the presence of inorganic mercury, and it was difficult to conclude whether there was a significant induction of hgcA and hgcB genes by inorganic mercury. Besides, no relationships between hgcA and hgcB expression levels and net mercury methylation could be observed when the strain was grown either under sulfate reduction or fumarate respiration, indicating that environmental factors had more influence than expression levels.
authors.affiliation: EEM-UMR IPREM CNRS 5254, Equipe Environnement et Microbiologie, University of Pau, Pau, France, marisol.goni@univ-pau.fr.
authors.forename: Marisol
authors.initials: M
authors.lastname: Goñi-Urriza
authors.forename: Yannick
authors.initials: Y
authors.lastname: Corsellis
authors.forename: Laurent
authors.initials: L
authors.lastname: Lanceleur
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Tessier
authors.forename: Jérôme
authors.initials: J
authors.lastname: Gury
authors.forename: Mathilde
authors.initials: M
authors.lastname: Monperrus
authors.forename: Rémy
authors.initials: R
authors.lastname: Guyoneaud
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D001673:Biodegradation, Environmental; D003901:Desulfovibrio / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D004734:Energy Metabolism / Q000187:drug effects; D004785:Environmental Pollutants / Q000378:metabolism* / Q000633:toxicity; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D008745:Methylation; D008767:Methylmercury Compounds / Q000378:metabolism* / Q000633:toxicity; D013440:Sulfides / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004785:Environmental Pollutants; D008767:Methylmercury Compounds; D013440:Sulfides