SysGen seminar – John Moreau – 9th September, 2016


The Mystery of Microbial Mercury Methylation: who’s doing it, how, where, and why?

Dr John Moreau
Earth Sciences, University of Melbourne

Friday 9th September
ESJ King Theatre, Medical Building, The University of Melbourne

Methylmercury is a potent microbially-produced neurotoxin found  globally in flooded sediments, waterways, estuaries, and seawater.  Although global atmospheric mercury emissions have been declining, global temperature increases could result in increased enzymatic conversion of previously deposited mercury to methylmercury.  After over a half-century of research into its mechanism of formation, the key functional genes involved in the transformation of Hg^2+ to CH(sub)3Hg^+ were only discovered within the last several years.  However, we still do not understand the geographical or phylogenetic distribution of these genes, their evolution, their expression or relationship to metabolism and physiology, or their impacts on environmental biogeochemical mercury cycling.  This presentation will review what we know, what we think we know, and what we don’t know, as well as show some data from our recent finding of methylmercury formation by a major marine bacterium in supposedly “pristine” Antarctic waters.

As a geomicrobiologist, Dr Moreau conducts cross-disciplinary research in geochemistry, mineralogy and environmental microbiology on questions that address the impact of microbes on geological materials and processes. His work includes the study of microbial interactions with heavy metals, the evolution of sulfate-reducing bacteria, and the activity of the deep subsurface microbial biosphere. Dr Moreau employs a range of research approaches involving electron microscopy, advanced chromatography and spectroscopy and genomics. He obtained his Ph.D from the Department of Earth and Planetary Science at the University of California, Berkeley, in 2006, and served as a U.S. National Research Council Postdoctoral Fellow with the U.S. Geological Survey from 2006-2008, prior to taking up his current appointment.


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