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Team:Bielefeld-CeBiTec/Results/rMFC/Construction
From 2014.igem.org
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During our research we discovered the H-cell reactor that seemed to meet with our needs. (<a href="#Park1999">Park et al., 1999</a>)<br> | During our research we discovered the H-cell reactor that seemed to meet with our needs. (<a href="#Park1999">Park et al., 1999</a>)<br> | ||
We approached two different concepts to realize the reactor construction. One of our H-cell reactors was constructed with the possibilities given to us by the facillities of our university. We instructed the glass workshop to modify two glass bottles by adding a glass-flange. Besides that the technical workshop build the lids from stainless steel. This approach had the advantage that we could influenze the design and had to make precise design drawings especially for the connections in the lids. <br> | We approached two different concepts to realize the reactor construction. One of our H-cell reactors was constructed with the possibilities given to us by the facillities of our university. We instructed the glass workshop to modify two glass bottles by adding a glass-flange. Besides that the technical workshop build the lids from stainless steel. This approach had the advantage that we could influenze the design and had to make precise design drawings especially for the connections in the lids. <br> | ||
| - | The second H-cell reactor was a commercially available system by <a href"http://adamschittenden.com/Glass%20Microbial%20Fuel%20Cells.html">Adams & Chittenden scientific glass</a>. The commercial system had a smaller volume and the benefit of a larger flange diameter. The necessary lids for that system were also custom design by our workshop. In figure | + | The second H-cell reactor was a commercially available system by <a href"http://adamschittenden.com/Glass%20Microbial%20Fuel%20Cells.html">Adams & Chittenden scientific glass</a>. The commercial system had a smaller volume and the benefit of a larger flange diameter. The necessary lids for that system were also custom design by our workshop. In figure 1 you can see both reactors in comparison. |
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<font size="2" style="text-align:left;"><b>Figure 2</b>: <b>1</b> Custom designed lids that profide connections for: a pO<sub>2</sub>-electrode, a pH-electrode, an entrance for reference and working electode, air output, heating coils and acid/ base input for pH control, <b>2</b> Heating coils, <b>3</b> Clamps for the flange connection <b>4</b> Sealing rings.</font> | <font size="2" style="text-align:left;"><b>Figure 2</b>: <b>1</b> Custom designed lids that profide connections for: a pO<sub>2</sub>-electrode, a pH-electrode, an entrance for reference and working electode, air output, heating coils and acid/ base input for pH control, <b>2</b> Heating coils, <b>3</b> Clamps for the flange connection <b>4</b> Sealing rings.</font> | ||
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| + | The H-cell is suitable for experiments concerning the investigation of mediator redox-characteristics and indirect electron transfer into electrotrophes. | ||
| + | <br> | ||
| + | In addition to the H-cell design we thought of an alternative reactor design that meets with the requirements of direct electron transfer. To enable direct electron transfer it is necessary that there is a large electrode surface provided to the microorganisms. Furthermore substrate limitation should be avoided. To meet with these requirements it is favourable to have an reactor that can be continiously driven. Our proposed solution | ||
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| + | <h6>Testing the set up</h6> | ||
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<div class="element" style="margin: 10px 10px 10px 10px; padding: 10px 10px 10px 10px"> | <div class="element" style="margin: 10px 10px 10px 10px; padding: 10px 10px 10px 10px"> | ||
Revision as of 21:11, 16 October 2014
Module I - reverse microbial fuel cell (rMFC)
Construction of an electrobiochemical reactor
We planned to design a reactor system that is suitable to investigate the electrochemical behaviour in bioprocesses. That includes the possibility to characterize mediators and different electrode materials on the one hand and the electron uptake into the cells on the other.
During our research we discovered the H-cell reactor that seemed to meet with our needs. (Park et al., 1999)
We approached two different concepts to realize the reactor construction. One of our H-cell reactors was constructed with the possibilities given to us by the facillities of our university. We instructed the glass workshop to modify two glass bottles by adding a glass-flange. Besides that the technical workshop build the lids from stainless steel. This approach had the advantage that we could influenze the design and had to make precise design drawings especially for the connections in the lids.
The second H-cell reactor was a commercially available system by Adams & Chittenden scientific glass. The commercial system had a smaller volume and the benefit of a larger flange diameter. The necessary lids for that system were also custom design by our workshop. In figure 1 you can see both reactors in comparison.
Figure 2: 1 Custom designed lids that profide connections for: a pO2-electrode, a pH-electrode, an entrance for reference and working electode, air output, heating coils and acid/ base input for pH control, 2 Heating coils, 3 Clamps for the flange connection 4 Sealing rings. The H-cell is suitable for experiments concerning the investigation of mediator redox-characteristics and indirect electron transfer into electrotrophes.
In addition to the H-cell design we thought of an alternative reactor design that meets with the requirements of direct electron transfer. To enable direct electron transfer it is necessary that there is a large electrode surface provided to the microorganisms. Furthermore substrate limitation should be avoided. To meet with these requirements it is favourable to have an reactor that can be continiously driven. Our proposed solution
Testing the set up
Cyclic voltammetry - mediator characterization
During our experiments we used a Ag/AgCl reference electrode for measuring the working electrode potential. The counter electrode, which completes the cell circuit, was made from platinum wire. Platinum has the advantage that it is an inert conducter.
Cultivation - constant voltage
The first experiments in the H-cell reactor were performed under constant direct voltage. These experiments were performed to test the set up. We investigated if E. coli was able to grow in the needed voltage range and if the different mediators influence the cells if a small electric current is applied.
Chronoamperometry - current consumption
Figure 2: Overlay of the chronoamperometric measurements from cultivation A B and C.
Flow Cell
References
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Park, D. H.,Laivenieks, M., Guettler, M. V., Jain, M. K. & Zeikus, J.G. (1999) Microbial utilization of electrically reduced neutral red as the sole electron donor for growth and metabolic production. In: Appl. Environ. Microbiol., 65 (7), pp. 2912 - 2917.
