Effect of Dissolved and Bacterial Cell Envelop-Bound Highly Reactive Thiols on the Redox Transformation and Methylation of Mercury in the Landfill Leachate Environment(3/3)

While much progress has been made in the past decades towards understanding the multifaceted aspects of mercury methylation, due in large part to the identification of the methylating genes, many fundamental questions remain. Indeed, recent evidence shows that bacterial cell envelope thiols can dominate Zn, Cd, and Hg sorption; however, the ability to quantitatively assess the importance of this on the speciation, distribution, bioavailability, and transformation of these elements in realistic systems is lacking.Here we propose to use the novel fluorophore approach to evaluate the environmental factors that control cell envelope R-SH site concentrations and binding affinities for Hg under realistic environmental conditions. Specifically, we will probe the role and effect of these R-SH sites on the redox transformation and methylation of Hg in the landfill leachate environment. Nonetheless, the results from this study can be applied not only to contaminant transport modeling, but also to bioremediation engineering and to understanding Hg cycling in the environment in general.