Redox Mediators of Shewnella Bacterial Biofilms Using SECM

Monday, May 12, 2014: 14:00
Floridian Ballroom E, Lobby Level (Hilton Orlando Bonnet Creek)
D. Cliffel and D. Crisostomo (Vanderbilt University)
With help from Dr. Sean Elliott of Boston University, we have obtained samples of Shewnella for scanning electrochemical analysis.  These are samples of S. Oneidensis (shewie). We were able to learn to grow shewie bacterial films on our transparent electrodes.   We also were able to do some basic electrochemical characterization of these films which confirmed their surface redox activity.  Our initial SECM results would be the first attempts at using a SECM to study a biofilm of any type, but unfortunately the tip electrodes kept being coated by the sticky protein layer of the biofilm, which then fouled the electrochemical signals.  Our newest attempts are going to keep the tip electrode farther from the biofilm, but close enough to map the redox activity of the shewie bacteria.  This has led to our first manuscript using SECM to measure the amount of redox agents, specifically identified as riboflavin, coming out of the bacteria, and also confirmed by mass spectrometry.