Difference between revisions of "Team:Korea U Seoul/Experiments"
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| − | <h4>1.Preparing Agar degrading Enzymes</h4> | + | <h4>1.Preparing Agar degrading Enzymes</h4><br> |
<p><font size=4>We used 3 enzymes to degrade agar in our device which are, Agarase, NABH (Neoagarobiose hydrolase), and AHGD (anhydrogalactose dehydrogenase). | <p><font size=4>We used 3 enzymes to degrade agar in our device which are, Agarase, NABH (Neoagarobiose hydrolase), and AHGD (anhydrogalactose dehydrogenase). | ||
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| − | <h4>2. Shewanella oneidensis MR-1</h4> | + | <h4>2. Shewanella oneidensis MR-1</h4><br> |
<p><font size=4>Shewanella oneidensis MR-1 is a bacteria that can reduce metal instead of oxygen, thus generating electricity in a battery device. We did not need any molecular work for this bacteria since it already has the function we need for our project. </p> | <p><font size=4>Shewanella oneidensis MR-1 is a bacteria that can reduce metal instead of oxygen, thus generating electricity in a battery device. We did not need any molecular work for this bacteria since it already has the function we need for our project. </p> | ||
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| − | <h4>3. Preparing Diaphorase</h4> | + | <h4>3. Preparing Diaphorase</h4><br> |
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| − | <h4>4. Battery Device Validation</h4> | + | <h4>4. Battery Device Validation</h4><br> |
<p><strong>1) MFC</strong></p> | <p><strong>1) MFC</strong></p> | ||
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| − | <p><strong>2) EFC</strong></p> | + | <p><strong>2) EFC</strong></p><br> |
<p><font size=4>>We also validated our device as an EFC. For the validation, diaphorase expressed E. coli BL21(DE3) was lysed by sonication and was applied into the anode chamber of our battery device. Methylene blue was given as the mediator. Lysed BL21(DE3) with void vector was the control. NADH was added to both batteries. </font> | <p><font size=4>>We also validated our device as an EFC. For the validation, diaphorase expressed E. coli BL21(DE3) was lysed by sonication and was applied into the anode chamber of our battery device. Methylene blue was given as the mediator. Lysed BL21(DE3) with void vector was the control. NADH was added to both batteries. </font> | ||
</p> | </p> | ||
<br><br> | <br><br> | ||
| − | <h4>5. EMFC Operation</h4> | + | <h4>5. EMFC Operation</h4><br> |
<p><font size=4>Our final goal was to prove that our device works as an EMFC. Shewanella oneidensis MR-1, BW25113 with displayed agar degrading enzymes, cell lysate of diaphorase expressed BL21(DE3), and cell lysate of TEV expressed BL21(DE3) was put into the anode chamber. Agar was used as the substrate. The battery device without agar was set as the control. </font> | <p><font size=4>Our final goal was to prove that our device works as an EMFC. Shewanella oneidensis MR-1, BW25113 with displayed agar degrading enzymes, cell lysate of diaphorase expressed BL21(DE3), and cell lysate of TEV expressed BL21(DE3) was put into the anode chamber. Agar was used as the substrate. The battery device without agar was set as the control. </font> | ||
Revision as of 14:35, 13 October 2016
Experiments
1.Preparing Agar degrading Enzymes
We used 3 enzymes to degrade agar in our device which are, Agarase, NABH (Neoagarobiose hydrolase), and AHGD (anhydrogalactose dehydrogenase). All of the enzymes are displayed on the surface of E.coli BW25113 using E.coli surface display vector pATLIC. These enzymes were already cloned and evaluated in theses. So we did not have to evaluate them ourselves. Related theses are listed on the reference list. One of the enzymes, NABH works as dimers, so it is not functional on the surface of E.coli. However, our surface display system can solve this problem by adding TEV protease. TEV protease site exist in our surface display vector pATLIC. If you add TEV into the surface displayed E.coli culture, TEV will cut the TEV site and the displayed protein will be ‘secreted’. TEV was already cloned in pET vector in our lab, so we also did not have to clone it for ourselves. TEV was expressed in BL21(DE3).
2. Shewanella oneidensis MR-1
Shewanella oneidensis MR-1 is a bacteria that can reduce metal instead of oxygen, thus generating electricity in a battery device. We did not need any molecular work for this bacteria since it already has the function we need for our project.
3. Preparing Diaphorase
Diaphorase is a type of enzyme that can generate electricity using NAD(P)H as the source of electron. The gene of the diaphorase is from sus scrofa, which is pig. It has been codon optimized and synthesized. We then used it to clone it into an expression vector pB3, and it was expressed in BL21(DE3). It was then tested in diaphorase assay to check its activity.
4. Battery Device Validation
1) MFC
We measured the voltage that Shewanella oneidensis MR-1 produce when formate is given since MR-1 uses formate to generate electricity. As controls, we measured the voltage of the battery with E. coli BW25113 in the anode chamber, and the battery without microbes. Methylene blue was given as the mediator. The purpose of this experiment is to make sure that our battery device works as an MFC.
2) EFC
>We also validated our device as an EFC. For the validation, diaphorase expressed E. coli BL21(DE3) was lysed by sonication and was applied into the anode chamber of our battery device. Methylene blue was given as the mediator. Lysed BL21(DE3) with void vector was the control. NADH was added to both batteries.
5. EMFC Operation
Our final goal was to prove that our device works as an EMFC. Shewanella oneidensis MR-1, BW25113 with displayed agar degrading enzymes, cell lysate of diaphorase expressed BL21(DE3), and cell lysate of TEV expressed BL21(DE3) was put into the anode chamber. Agar was used as the substrate. The battery device without agar was set as the control.
References
- Yun, Eun Ju, et al. "Production of 3, 6-anhydro-L-galactose from agarose by agarolytic enzymes of Saccharophagus degradans 2-40." Process biochemistry 46.1 (2011): 88-93.
- Yun, Eun Ju, et al. "The novel catabolic pathway of 3, 6‐anhydro‐L‐galactose, the main component of red macroalgae, in a marine bacterium." Environmental microbiology 17.5 (2015): 1677-1688.
- Ko, Hyeok-Jin, et al. "Functional cell surface display and controlled secretion of diverse agarolytic enzymes by Escherichia coli with a novel ligation-independent cloning vector based on the autotransporter YfaL." Applied and environmental microbiology 78.9 (2012): 3051-3058.
- Wang, Victor Bochuan, et al. "Metabolite-enabled mutualistic interaction between Shewanella oneidensis and Escherichia coli in a co-culture using an electrode as electron acceptor." Scientific reports 5 (2015).
- Zhu, Zhiguang, et al. "A high-energy-density sugar biobattery based on a synthetic enzymatic pathway." Nature communications 5 (2014).
- Watson, Valerie J., and Bruce E. Logan. "Power production in MFCs inoculated with Shewanella oneidensis MR‐1 or mixed cultures." Biotechnology and bioengineering 105.3 (2010): 489-498.
