the wiatrowski lab

at Clark University


Liu Songnian, Ph.D. student

Bio: After receiving my Bachelor Degree from Shandong University at Weihai, China, I began my scientific career as a Ph.D. student in Dr. Wiatrowski’s lab in 2009. I also am a Teaching Assistant for Microbiology .

Research Interest: Mercury is an extremely toxic element that is a well known as a pollutant in aquatic environments. It exists in the environment with three different forms: ionic mercury, elemental mercury and methyl-mercury. These forms of mercury can be converted to each other by microorganisms. In surface waters, methyl-mercury can be biomagnified in the food chain. Mercury contamination of ecosystems may become a considerable health threat to human beings that eat fish. Mercury in aquatic environment often originates from atmospheric deposition due to coal fired power plant and discharge from hydroelectric and paper industries. Many microorganisms have been found to be resistant to mercury and may have genes that confer mercury resistance.

I am studying magnetotactic bacteria from the phylum of Alphaproteobacteria. They inhabit at the oxic-anoxic transition zones in aquatic environments. A well-known characteristic of all magnetotactic bacteria is their production of magnetosomes, which are chains of elongated, iron-rich crystals that consist of magnetite (Fe3O4). Previous research demonstrated synthetic magnetite can reduce ionic mercury to elemental mercury. Thus, magnetotactic bacteria could potentially interact with ionic mercury and reduce it to elemental mercury. Currently, I am investigating whether magnetotactic bacteria will reduce ionic mercury by a chemical reaction with intracellular magnetosomes or by the enzyme mercury reductase. As several fully sequenced genomes from magnetotactic bacteria become available, I am able to harness various powerful bioinformatic and molecular techniques.


Biology Department, Clark University
Lasry Biological Science Center
950 Main St., Worcester, MA 01610 USA
Lab: 508.793.7163

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