University of Minnesota
MICaB Graduate Program
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Current Students

Bridget Conley

Thesis Advisor: Jeff Gralnick

Year entered: 2015

Degrees received:
B.S., North Carolina State University, Raleigh, NC

Honors and Awards:

  • Viksnins, Harris & Padys MICaB Award, 2015
  • BTI Travel Grant, 2016
  • MPGI Travel Grant, 2016


Thesis research:

Electricity is life. Cells use electrons in order to generate energy for the cell, but those electrons must go somewhere once they have been used because they cannot be destroyed. Humans breathe oxygen to accept electrons, but microorganisms have the ability to use a vast diversity of other compounds to accept electrons. One specialized strategy is to breathe metals such as Fe(III) and Mn(IV) as electron acceptors; however, Fe and Mn minerals are insoluble in most conditions. Microorganisms that utilize this metabolic strategy move electrons outside of the cell to the electron acceptor via extracellular electron transport. Shewanella and Geobacter are model systems for studying metal reduction, and we now know a general mechanism for extracellular electron transport in these microorganisms. There are numerous reports in the literature of microorganisms with the ability to breathe metals from all over the microbial tree of life. Microbes from extreme temperatures, pH, and salinity have all been described to perform metal reduction; however, many of these reports have not been investigated further with biochemical or genetic descriptions of how extracellular electron transfer is occurring. My PhD project is to discover and characterize novel pathways for extracellular electron transport in bacteria other than the model systems, Shewanella and Geobacter. Thus far I have characterized the mechanisms for extracellular electron transport in Aeromonas hydrophila, a cousin to Shewanella. Aeromonas spp. use aspects similar to Shewanella but also have unique components.