November 7, 2013 by Heather Wiatrowski
It’s been a wonderfully gratifying season in the Wiatrowski lab!
I just received word that PhD student Yingjiao Wang and master’s student Tyler Robison’s work has been published online in the journal Biometals. You can find the article here for now: http://link.springer.com/article/10.1007%2Fs10534-013-9679-2 DOI 10.1007/s10534-013-9679-2
The paper is titled “The impact of ionic mercury on antioxidant defenses in two mercury-sensitive anaerobic bacteria”.
What is this research about? Well, many bacteria resist ionic mercury, Hg(II), using a mercury resistance operon (mer). When bacteria have mer, in the presence of Hg(II), they transport Hg(II) into the cell and reduce it to Hg(0). Hg(0) is less toxic, and plus, is a gas – so it evaporates and leaves the bacteria’s immediate environment.
We asked the question, “What happens when bacteria that don’t have mer are exposed to Hg(II)”? It turns out, we know how Hg(II) effects antioxidant defenses in mammals, but not in bacteria! Yingjiao and Tyler set to work characterizing the impact of mercury on glutatione, thioredoxin, and lipid peroxidation in the bacteria Shewanella oneidensis MR-1 and Geobacter sulfurreducens PCA.
A big surprise for us was the observation that Shewanella is more resistant to Hg(II) under conditions when more Hg(II) enters the cell. We though it would be the other way around! We think that when Hg(II) enters the cytoplasm, it may be detoxified by binding to glutathione.