Genome insights of mercury methylation among Desulfovibrio and Pseudodesulfovibrio strains

Publication date: Available online 23 October 2019Source: Research in MicrobiologyAuthor(s): Marisol Goni-Urriza, Christophe Klopp, Magali Ranchou-Peyruse, Anthony Ranchou-Peyruse, Mathilde Monperrus, Bahia Khalfaoui-Hassani, Rémy GuyoneaudAbstractMercury methylation converts inorganic mercury into the toxic methylmercury, and the consequences of this transformation are worrisome for human health and the environment. This process is performed by anaerobic microorganisms, such as several strains related to Pseudodesulfovibrio and Desulfovibrio genera. In order to provide new insights into the molecular mechanisms of mercury methylation, we performed a comparative genomic analysis on mercury methylators and non-methylators from (Pseudo)Desulfovibrio strains. Our results showed that (Pseudo)Desulfovibrio species are phylogenetically and metabolically distant and consequently, these genera should be divided into various genera. Strains able to perform methylation are affiliated with one branch of the phylogenetic tree, but, except for hgcA and hgcB genes, no other specific genetic markers were found among methylating strains. hgcA and hgcB genes can be found adjacent or separated, but proximity between those genes does not promote higher mercury methylation. In addition, close examination of the non-methylator Pseudodesulfovibrio piezophilus C1TLV30 strain, showed a syntenic structure that suggests a recombination event and may have led to hgcB depletion. The genomic analyses id...
Source: Research in Microbiology - Category: Microbiology Source Type: research