| Category | ENEV | P20 | Comparing the Electricity Output in Microbial Fuel Cells by |
| Bacteria Type |
| Abstract | This experiment tested the voltage generated by different types of |
| bacteria in microbial fuel cells. Microbial fuel cells are an alternative |
| energy source to fossil fuels and they use organic waste to generate |
| electricity. This is done using bacteria that consume the organic waste |
| and energy and electrons. However, microbial fuel cells are not efficient |
| enough for practical use as the amount of electricity they generate |
| changes over time and the soil bacteria that are commonly used in |
| these fuel cells aren't always easy to obtain in isolated samples. This is |
| why four other types of soil bacteria were used in this project. The |
| types of bacteria that were used were Rhodospirillum rubrum, |
| Clostridium beijerinckii, Pseudomonas putida, and Mycobacterium |
| nonchromogenicum. R. rubrum is facultatively anaerobic and due to the |
| versatility in the ways that it gets energy from food, it was hypothesized |
| that this bacteria would generate the highest voltage. |
| A different type of bacteria was added to nutrient broth in the anode |
| chamber of each microbial fuel cell. There were three trials, or three |
| microbial fuel cells for each type of bacteria. A multimeter was used to |
| record the voltage generated by each trial for three days. With an |
| overall average of .0707 volts, R. rubrum generated the highest voltage |
| and the hypothesis was supported. The data shows that the voltages |
| generated were low, so in the future an electron- extracting mediator |
| can be tested to improve voltages. This data can help improve the |
| efficiency of microbial fuel cells by providing data on more easily |
| obtained bacteria that can be used in microbial fuel cells. |
| Bibliography | http://journal.frontiersin.org/researchtopic/3845/electrochemically- |
| active-microorganisms |
| http://chemistry.stackexchange.com/questions/5477/why-is-it-important- |
| to-use-a-salt-bridge-in-a-voltaic-cell-can-a-wire-be-used |
| http://www.sciencebuddies.org/science-fair-projects/electricity- |
| magnetism-electromagnetism-tutorial#currentelectricity |
| http://www.sciencebuddies.org/science-fair- |
| projects/project_ideas/Energy_p026.shtml#background |
| https://microbewiki.kenyon.edu/index.php/Rhodospirillum_rubrum |
| https://en.wikipedia.org/wiki/Pseudomonas_putida |
| https://en.wikipedia.org/wiki/Microbial_fuel_cell#Mediator-free |
| https://en.wikipedia.org/wiki/Mycobacterium#Mycobacterium_nonchrom |
| ogenicum.2Fterrae_clade |
| https://en.wikipedia.org/wiki/Clostridium_beijerinckii |