Swedish forest soil microbes produce toxic mercury compound

The formation of the powerful neurotoxic methylmercury (MeHg) is a microbially mediated process that has raised much concern as it poses threats to both nature wildlife and human health. To understand the biogeochemical processes involved in the formation of this pollutant, researchers from Uppsala University have now mapped the microbial populations that contribute to MeHg formation in boreal forest soils across Sweden.  

High-throughput next generation sequencing of a component of the microbial protein-production machinery, as well as the genes for a MeHg-producing enzyme, was conducted at the SciLifeLab National Genomics Infrastructure. Along with geochemical characterization of the 200 soil samples, the results shed light on the biogeography of microorganisms responsible for MeHg formation in the Swedish boreal landscape.

The obtained sequences could be ascribed to several diverse groups of microorganisms, including Proteobacteria, Firmicutes, and Methanomicrobia. The results also suggest that MeHg formation is linked to the composition of non-mercury methylating bacterial communities, likely acting as providers of growth factors for the microorganisms actually carrying out the formation of MeHg.

Read the full paper in Scientific Reports