Team:Cornell/testing/project/wetlab/4/1

Reactor Testing

Overview of Characterization in Bioelectrochemical Stystems

As described in the Chassis section, S. oneidensis MR-1 is capable of shuttling electrons through the Mtr pathway to reduce Fe(III) to Fe(II) because of the negative free energy change associated with the redox reaction. Thus, in order for Shewanella to transfer electrons to an electrode, the redox potential of an electrode must be poised to that of Fe(III)/Fe(II). We accomplish this with a three electrode system, controlled by a potentiostat. [[LINK TO THE PAGE ON THE POTENTIOSTAT]]. In short, this works by setting the potential of a working electrode (WE) with respect to a Ag/AgCl reference eletrode (RE), Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aenean rutrum aliquam ipsum, quis lobortis ante vestibulum eu. Nullam eget est justo. Fusce commodo arcu a dui bibendum aliquet. Sed justo eros, dictum quis dictum a, laoreet ut urna. Duis in felis at felis tempor rutrum et sed metus. In sollicitudin adipiscing nibh, eu euismod lectus faucibus eget. Cras ut nulla non velit consequat venenatis in ac velit. Etiam a elit justo. Etiam gravida nulla sit amet eros suscipit at auctor orci porta.
[[https://static.igem.org/mediawiki/2012/1/1b/Cornell_Reactor.jpg]]

First Lessons Learned: Control Reactors

In order to enhance the field-deployability of our final device, we initially decided to feed our reactors with LB, since a very concentrated LB source fed at a low flow rate could sustain our field reactors for extended periods of time without taking up much physical space. However, upon setting up control reactors—both in batch and continuous flow operation—we discovered that wild type S. oneidensis MR-1 produced significantly less current when fed with LB than M4—a commonly used media for Shewanella-inoculated bioelectrochemical systems.