Lake snow as a mercury methylation micro-environment in the oxic water column of a deep peri-alpine lake

Anaerobic mercury methylators inhabit sinking particles of oxic water columns

“…Villar et al (2020) found hgcA genes in the oxic water of the open ocean suggesting the presence of Hg methylators in this environment. In freshwater systems, while two previous study showed that sinking particles were an important environment prone to MeHg formation (Gascón Díez et al, 2016;Gallorini and Loizeau, 2022), no evidence on the presence of the hgcA gene was reported, hampering the understanding of anaerobic biological processes involved in MeHg formation in sinking particles from oxic water columns. Describing the anaerobic microorganisms involved in MeHg formation in sinking particles improves current knowledge and understanding on the niches that Hg methylators can successfully colonize.…”