Team:Korea U Seoul/Notebook

Notebook

Notebook

Week 1.

  1. We took Shewanella oneidensis MR-1 from our instructor, Seungwoo Baek, and made pure culture of Shewanella in LB solid culture with Ampicillin.
  2. We tested microbial fuel cell(MFC) device we've lent from GIST, Gwangju Institute of Science and Technology. Our test was measured by Fluke 101 multimeter.
  3. We got clones of agar degrading enzymes and TEV from our lab.

Week 2.

  1. We made a simple device using 50mL tube, aluminium foil, and agar salt bridge, which was improved than the last device.
  2. We connected our batteries in series. Whole voltage was lower than we expected, but it was same with sum of each batteries voltage.
  3. Also, We bought an amperemeter and checked the batteries.
  4. In addition, we made a hypothesis that current will be increased if we put more concentrated culture of Shewanella.
  5. Diaphorase was cloned into pB3.

Week 3.

  1. We tested last week's hypothesis. Different volume of cultured Shewanella was concentrated by centrifuge, and put into simple MFC.
  2. Electric current was increased, but it remained same after certain concentration.
  3. We discussed that only Shewanella in biofilm will affect the electricity.
  4. Electric current decreased after few seconds.

Week 4.

  1. Cultured Shewanella did not grow.
  2. Our Instructor gave us an advice to newly streak Shewanella so we made a new Shewanella plate.
  3. We and instructor tried to turn on the multimeter which borrowed from GIST, but we did not know how to use it.
  4. Multimeter needed an program based on excel.
  5. We changed our electrode to carbon for accuate measurement because aluminium and iron electrode can affect the results.

Week 5.

  1. We thought that we could run a scientific calculator if we gather enough electricity.
  2. Caculator's mercury cell was 1.5V and 20mA.
  3. I made a large MFC with 500mL water bottle, but it did not work.
  4. Color of Shewanella looked strange. We thought it was contaminated, so we cultured it again.

Week 6.

  1. For modeling, I made a growth curve of Shewanella.
  2. Whole Korea_U_Seoul members went to Gwangju, and opened a booth that introduces our project.
  3. In addition, we visited Energy & Biotechnology Lab in GIST. We asked for some advice about our project, and how to run the multimeter.
  4. Therefore, We succeeded in running our multimeter.

Week 7.

  1. We tested our multimeter with a 1.5V battery.
  2. We could draw a I-V graph and time-V graph by using excel.
  3. By that graph, we can calculate open circuit voltage(OCV) and inertial resistance.

Week 8.

  1. We made a new device. It is made out of 15mL and 50mL Falcon tube and cap.
  2. We studied a paper about coculture of E. coli and Shewanella.
  3. For the next experiment, we cultured E. coli DH10B in LB.

Week 9.

  1. We did an experiment to know that coculture of E. coli and Shewanella raises electricity.
  2. We could not see any differences in our experiment.
  3. Electrode of MFC is changed to a carbon paper.
  4. Carbon paper's back is laminated with coating paper.

Week 10.

  1. Carbon paper MFC's current is less than last MFC.
  2. Inner solution of MFC was leaked.
  3. So I made a new MFC with waterproof silicon adhesive, not glue gun.

Week 11.

  1. I found that ferricyanide ion turn into ferrocyanide ion, and the color changed from yellow to blue.
  2. Therefore, the color of cathode changed to green.

Week 12.

No experiment due to seminar.

Week 13, 14, 15

No experiment due to hospitalization.

Week 16.

  1. We studied a paper that fixation of diaphorase onto electrodes.
  2. But experiments were too complicated, so we gave up.

Week 17, 18

  1. We did an MFC validation with Shewanella, phosphate buffer saline(PBS), and galactose.
  2. We did same experiment 3 times.
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Week 19.

  1. I changed the mulitimeter's circuit to test 5 fuel cell at the same time.
  2. We did EFC test with 3 sample, E. coli(Diaphorase expressing), yeast, and E. coli(Diaphorase expressing) + yeast.
  3. All cells was lysed by ultrasonication.

Week 20.

  1. We did similar experiment with last week, but sample was treated with centrifuge.
  2. We thought that the agarase in anolyte can react with agar in salt bridge, so we paste cellophane membrane at anode part of salt bridge. Cellophane membrane was fixed by 15mL Falcon tube's cap.
  3. Part cloning was done

Week 21.

  1. I made 6 new device. The parts with pasted with glue gun was melted during autoclaving, so I changed it with waterproof silicon adhesive.
  2. We did a MFC validation with Shewanella, E. coli BW25113, and a control group(No cells).
  3. We did the experiment 3 times.

Week 22.

  1. We did an EFC validation this week.
  2. Transformed E. coli treated with arabinose or IPTG induction depending on its function.
  3. We did the experiment 3 times.

Week 23.

  1. The EFC validation graph looks strange.
  2. Our professor told us that the amount of NADH might be too small.
  3. So we did the experiment again with adding some NADH.

Week 24.

  1. We created the whole EMFC system, and we measure the voltage. External resistance was 1,000 Ohm.
  2. We draw the graph of EMFC, and compared with contrast.