Team:UTArlingtonTexasUSA/Description
INSPIRATION & DESCRIPTION
Research on the different uses and methods of microbial fuel cells (MFC's) as bio-sensing modalities has been successfully proposed and developed in previous competitions. Our research group was inspired by the 2007 Glasgow team’s prediction of pyocyanin to power an E- coli based MFC.
The reduction-oxidation of pyocyanin, a zwitterion, can be harnessed by the cells to indirectly deposit electrons on the anode electrode of the MFC; If the cells were to respond to a pollutant by producing pyocyanin, we can observe the change in current as an indication of the presence of the pollutant. Our team aims to investigate this sensing system by making the bacteria produce fluorescent proteins in response to the presence of xylene, a BTEX member pollutant, and utilizing this colorimetric change to correlate concentrations.
Our working microbial fuel has a modular 3D printed cassette that contains a salt bridge [3M KCl, 3% agar (aq)] and two water resistant chambers that hold carbon cloth electrodes and E. coli in M9 medium. The anodic chamber contains methylene blue [10mM in M9 medium], the cathodic chamber utilizes potassium ferricyanide [20 mM in M9 medium] as the cathodic electron acceptor. Our team has successfully constructed a microbial fuel cell that utilizes E. coli and methylene blue (mediator) to establish proof of Glasgow's concept before integrating synthetic biology.
The XYLRR, PHZ and GFP genes were transformed into E.coli k-12. We are still in the process of transforming all three genes onto the same vector and ultimately into a chassis. The mcherry gene was initially found to have a dim phenotype but upon optimization of the sequence this was enhanced, and a red fluorescent light was observed. A possible hypothesized biosensing system is the placement of XYLR is a consecutive combination with GFP in order to detect presence of xylene (a pollutant). The rationale of our project lies in implementing all of these gene parts into a single module, for which the inspiration is derived from 2007 Glasgow’s predicted model.
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