Designer Space Slime Fuels Electricity

Scientists have pinpointed two types of stratospheric bacteria and transformed it into a slimy film that doubles the efficiency of fuel cells that run on microbes. It could mean power for underdeveloped locales that currently don't have electricity.

Scientists surveyed 75 bacteria from the stratosphere -- the second layer of the earth's atmosphere where satellites orbit -- to find the most efficient bacteria for generating power. Their bacteria pageant led them to two super-efficient bacteria: B. stratospheric and B. altitudinal.

Besides having really fun names, B. stratospheric and B. altitudinal fell from the atmosphere into the Wear Estuary in Country Durham, where scientists from Newcastle University in the UK collected them. They then used the bacteria to create a designer slime and build the most efficient microbial fuel cell ever. It's twice as fast as anything like it today: 200 watts per cubic metre versus 105 watts.

That's still not a huge amount of power, but it would be enough to cheaply generate electric lights and provide a power source to underdeveloped locations, according to the scientists, who are published their work in the American Chemical Society's Journal of Environmental Science and Technology.

Microbial fuel cells work like a battery but use bacteria to convert organic compounds into electricity using "bio-catalytic oxidation". The slime, aka biofilm, coats carbon electrodes and as the bacteria munch away on the carbon, they produce electrons that pass into the electrodes and generate electricity.

Scientists have created microbial fuel cells before, but this is the first time they've handpicked bacteria for their efficiency. We've barely made a dent in discovering all the types of bacteria that exist, so there's no telling how much more powerful space slime might become. [Journal of Environmental Science and Technology]