"
Team:Cornell/testing/project/wetlab/4/1
From 2012.igem.org
(Difference between revisions)
| Line 75: | Line 75: | ||
<img src="https://static.igem.org/mediawiki/2012/1/1b/Cornell_Reactor.jpg"> | <img src="https://static.igem.org/mediawiki/2012/1/1b/Cornell_Reactor.jpg"> | ||
</div> | </div> | ||
| + | |||
| + | <div class="twelve columns"> | ||
| + | <img class="inline" src="https://static.igem.org/mediawiki/2012/1/1c/LBvM4_small.png"> | ||
| + | <b> Fig. 1. Current production over time is plotted for batch reactors inoculated with wildtype <i>S. oneidensis</i> MR-1 growing on M4 media (blue) and LB media (green). Maximum current production from M4-fed <i>Shewanella</i> is much greater than that from LB-fed.</b><br><br> | ||
| + | |||
| + | |||
| + | </div><div class="nine columns"> | ||
| + | |||
| + | 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. | ||
| + | |||
| + | </div><div class="three columns"></div> | ||
| + | |||
| + | |||
| + | |||
| + | |||
| + | |||
</div> | </div> | ||
<div class="row"> | <div class="row"> | ||
| Line 102: | Line 118: | ||
<div class="twelve columns"> | <div class="twelve columns"> | ||
<img class="inline" src="https://static.igem.org/mediawiki/2012/6/60/SAME_I_invis_small.png"> | <img class="inline" src="https://static.igem.org/mediawiki/2012/6/60/SAME_I_invis_small.png"> | ||
| - | <b> Fig. | + | <b> Fig. 2. Current production over time is plotted for continuous flow reactors inoculated with our salicylate reporter strain (blue) and wildtype <i>S. oneidensis</i> MR-1 (green). Both duration of transient period and value of saturating current are approximately equal for reactors corresponding to both strains. </b><br><br> |
Revision as of 08:34, 3 October 2012
-
Wet Lab
- Overview
- Chassis
- DNA Assembly
- Testing & Results
- Future Work
- Animation
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, to encourage Shewanella to transfer electrons to an electrode, we poise the redox potential of an electrode to that of Fe(III)/Fe(II) in a three electrode system, controlled by a potentiostat. [[LINK TO THE PAGE ON THE POTENTIOSTAT]]. In short, this instrument works by setting the potential of a working electrode (WE) with respect to a Ag/AgCl reference eletrode (RE) by injecting current through a counter electrode (CE). These electrodes can be seen in the schematic representation of our single-compartment bioelectrochemical reactors shown below.
Fig. 1. Current production over time is plotted for batch reactors inoculated with wildtype S. oneidensis MR-1 growing on M4 media (blue) and LB media (green). Maximum current production from M4-fed Shewanella is much greater than that from LB-fed.
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.
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.Naphthalene & Salicylate Sensing
First characterized naphthalene sensors with salicylate, since our system indirectly senses naphthalene via salicylate.Uninduced salicylate reporter produces same current as MR-1 in rich M4 media.
First attempt to diagnose problem: Switch to minimal M4... Producing higher current, but we're still not getting a salicylate response.
Next attempt: Poise the working electrode at a higher potential in attempt to get more MtrC and MtrA for MtrB to associate with. Didn't quite do the trick either.
Fig. 2. Current production over time is plotted for continuous flow reactors inoculated with our salicylate reporter strain (blue) and wildtype S. oneidensis MR-1 (green). Both duration of transient period and value of saturating current are approximately equal for reactors corresponding to both strains.
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.
