Amanda Nicole Payne
- Bio:
I was raised in Zurich, Switzerland were I attended elementary and junior high school. After graduating high school from Brenau Academy in Georgia in 1998, I attended Georgia State University where I earned a bacheloršs degree in Biology with magna cum laude honors. In 2003 I completed a Masteršs degree in Applied Biology at the Georgia Institute of Technology working on the molecular mechanisms of microbial metal reduction. I am currently continuing to study microbial reduction and have focused my thesis work on the mechanisms of microbial Tc(VII) reduction by Shewanella oneidensis MR-1.- Abstract:
The ability to enzymatically reduce Tc(VII) is found in several environmentally important groups of proteobacteria including members of the genera Shewanella, Geobacter, Deinococcus, Escherichia and Desulfovibrio. Microbial reduction of soluble Tc(VII) results in formation of highly insoluble Tc(IV) oxides, a Tc immobilization process that forms the basis of alternate remediation strategies. Despite its potential benefits, the molecular mechanism of Tc(VII) reduction remains poorly understood. Shewanella oneidensis MR-1 provides an attractive model for studying the molecular mechanism of Tc(VII) reduction because genetic manipulations may be carried out aerobically and its genome sequence is available. S. oneidensis displays remarkable respiratory diversity as it is able to respire in addition to O2, a wide variety of both soluble and insoluble compounds as alternate electron acceptor. Random mutagenesis of wild-type S. oneidensis colonies using the chemical mutagen ethyl methane sulfonate has resulted in a set of six Tc(VII) reduction-deficient mutants. The anaerobic respiratory deficiencies of each Tc(VII) reduction-deficient mutant was determined by anaerobic growth on various combinations of three electron donors (hydrogen, formate and lactate) and 14 terminal electron acceptors. Results indicate that the electron transport pathways to Tc(VII), NO3-, Mn(III), U(VI) and S2O3- share common structural or regulatory components. Proteomic tools including NATIVE-PAGE, SDS-PAGE, MALDI-TOF as well as genetic complementation experiments are being used to identify the genes and gene products required for microbial Tc(VII) reduction.
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