Scientists of the Washington State University fished multiple communities of extremophile bacteria from the alkaline hot springs of the Heart Lake Geyser Basin area, in Yellowstone National Park.
The bacteria, that thrive in environments with temperatures between 40-90 degrees Celsius, feed on pollutants and dump the electrons produced during the metabolic processes on metal surfaces-essentially, producing electricity. Cultivating these micro-organisms in the laboratory is very difficult, so the scientists enriched them in their native environment and captured them using a novel potentiostat and electrodes.
Another kind of microorganisms, the purple phototrophic bacteria, use organic molecules and nitrogen gas for photosynthesis. They are studied for their potential to use organic waste from sewers to fix CO2 and/or produce hydrogen, that could be used as fuel.
A group of scientists from the University of Alcalá, Spain, designed a bioelectrochemical system that uses bacterial metabolism to connect electrons. Another group, from UWE Bristol, designed a stable biological system that can treat waste, generate enough electricity to power mobile phones and at the same time minimizes pathogens, allowing for the treated effluents to be safely released.