University of Minnesota
MICaB Graduate Program
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Current Students

Eric Kees

Thesis Advisor: Jeff Gralnick

Year entered: 2013

Degrees received:
B.S., University of North Dakota, Grand Forks, ND, 2012

Honors and Awards:

  • UMII/MnDRIVE PhD Graduate Assistantship Program 2016


Shewanella oneidensis is a member of the dissimilatory metal reducing bacteria (DMRB), a highly diverse group of bacteria able to use a variety of soluble and insoluble terminal electron acceptors for respiration. S. oneidensis is one of the best studied organisms to date as a model for DMRB, with variety of biotechnological applications, including microbial fuel cells and bioremediation of toxic metal pollution. However, when grown in condition of electron acceptor limitation, Shewanella oneidensis exhibit a strong death phenotype with lysis following growth, without any apparent stationary phase. My project utilizes high‐throughput transposon screening  (Tn-seq) to understand pathways contributing to death and survival under electron acceptor limited conditions. As a synthetic solution to death under electron acceptor limitation, we have engineered a strain of S. oneidensis to produce the nonnative protein proteorhodopsin, a light-driven proton motive force generating pump used by many marine planktonic bacteria to survive in a steady state when nutrients are scarce. When introduced into S. oneidensis, proteorhodopsin has no discernable effect on growth but enables survival under electron acceptor limitation when supplied a sufficient source of light. By studying how S. oneidensis has incorporated this foreign energy source and for survival under challenging conditions, and by studying genetic factors that contribute to death under these conditions, we can hope to better devise and optimize metabolic pathways of interest to synthetic biology and biotechnological applications.