An exploration of current production and metal oxide reduction by Shewanella oneidensis MR-1 wild type and mutants

Mork Family Department of Chemical Engineering and Materials Science, Department of Earth Sciences, University of Southern California, Los Angeles, CA; Department of Earth Sciences, Rice University, Houston, TX; Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, South Korea; The J. Craig Venter Institute, La Jolla, CA; Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA; Institute for Environmental Genomics, Department of Botany and Microbiology, University of Oklahoma, Norman, OK; Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN; Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI; Korea Institute of Science and Technology, Seoul, Korea

	Abstract

Shewanella oneidensis MR-1 is a Gram negative facultative anaerobe capable of utilizing a broad range of electron acceptors, including several solid substrates. S. oneidensis MR-1 can reduce Mn(IV) and Fe(III) oxides, and can produce current in microbial fuel cells. The mechanisms that are employed by S. oneidensis MR-1 to execute these processes have not yet been fully elucidated. Several different S. oneidensis MR-1 deletion mutants were generated and tested for current production and metal-oxide reduction. The results showed that a few key cytochromes play a role in all of the processes but that their degree of participation in each process is very different. Overall, these data suggest a very complex picture of electron transfer to solid and soluble substrates by S. oneidensis MR-1.