What do you get when you take a circuit, a microbe like yeast, give it a little food and mix in some chemicals? Electricity.
It’s not as far-fetched as it might appear. All microbes have the potential to create electricity because biological processes such as digesting food work by passing electrons. University of Saskatchewan grad student Jonathan Godwin is improving the technology and hopes to make a microbe-based fuel cell that is cheap and non-toxic, according to a recent report from the institution.
Energy already can be captured by using chemicals called mediators to redirect the electricity into a circuit. However, mediators are problematic. They tend to be expensive and often toxic, potentially tainting all the byproducts of electricity microbes. Godwin has solved this problem by coating electrodes with the mediators, which allows the electricity to be harnessed in a more direct way. Godwin and Richard Evitts, a chemical engineering professor overseeing the project, then use photosynthesis to boost the electrical power in the cells.
How it works
In the fuel cell, yeast grows on a chemical-coated electrode. The electricity is collected as a byproduct, while the yeast continues with its normal process of digesting sugar and producing alcohol.
Mediator-coated electrodes produce less electricity than when the chemicals are mixed in. That’s where photosynthesis, the chemical process that plants use to turn sunlight into energy, comes in. The coated electrode takes electrons from the yeast and sends them through the circuit to a micro-algae, which uses the electrons in the energy-intensive process of photosynthesis. Poof! Electricity.
High-energy coated fuel cells are years from being used on a large commercial scale. However, if researchers can master how to collect electricity from everyday microbes using coated electrodes, they can use the same principle to apply it to other microbiological systems, according to the recent University of Saskatchewan article. For example, an alcohol-producing yeast could be used for brewing and to produce electricity at the same time.
[via: physorg]
Photo of yeast cells from Flickr user tjmwatson, CC 2.0
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