Uptake and Methylation of Mercury in Planktonic and Biofilm Cultures of Sulfate-Reducing Bacteria

Speaker: Dr. Chu-Ching Lin, Research Associate, Department of Civil and Environmental Engineering,
University of California, Los AngelesAbstract:
Mercury (Hg) methylation is the most critical Hg transformation in nature because the end product, methylmercury (MeHg), is a potent neurotoxin that can be effectively bioaccumulatd and biomagnified through food chains to become a level of a threat to human health and wildlife reproduction. It is well accepted that the dominant environmental Hg methylation process is mediated biologically, and sulfate-reducing bacteria (SRB) have been identified as the primary Hg methylators in a wide range of aquatic systems. While all previous Hg methylation studies to date have been conducted with planktonic SRB cultures, it is generally believed that the majority of bacteria in the environment live in surface-attached communities, or biofilms. Little work has been undertaken to investigate the role of biofilms in Hg cycling, particularly in the formation of MeHg. In this seminar, the effects of chemical speciation on uptake and methylation of Hg in both planktonic and biofilm cultures of the model microorganisms (E. coli and Desulfovibrio desulfuricans) will be discussed. Also, pathways of Hg methylation that caused the observation of differential Hg methylation capacity between planktonic and biofilm cultures of SRB will be touched.

Location: Kaprielian Hall (KAP) - 209

Audiences: Everyone Is Invited

Contact: Evangeline Reyes