Breathing without air

Geobacter metallireducens is a bacteria that lives in dirt. This organism is studied extensively because it is capable of taking electrons from hydrocarbons like acetate (vinegar) and depositing them on iron. The electrons flow through extensions of the bacteria called pili. Pili can be thought of as biological wires. G. metallireducens is often used in microbial fuel cells because of the bacteria's ability to deposit electrons onto metal.

By understanding the underlying cellular processes of these microbes, scientists can make microbial fuel cells more efficient. One way to learn about cellular processes is by taking genes out of its genome and observing the change in phenotype.

My research involved deleting genes from the G. metallireducens genome and observing its ability to deposit electrons on iron. The genes I was interested in coded for proteins called cytochromes. These cytochromes contribute to the conductive nature of the pili. I hypothesized that without them, electrons would not be able to flow from the bacteria to the iron. Understanding the role and importance of these cytochrome proteins could contribute to the viability of the microbial fuel cell as a renewable energy source.