Sewage is loaded with energy-rich sugars that researchers have struggled for years to convert into useful power. To do so, investigators have experimented with nature's experts on breaking down waste - bacteria.

“It's kind of like the movie The Matrix,” said environmental engineer Bruce Logan at Penn State University. “Instead of wiring people up to generate electricity, we are using bacteria to directly generate electricity.”
Scientists have experimented with a variety of bacteria, but one kind that environmental microbiologist Derek Lovley at the University of Massachusetts at Amherst and his colleagues have focused on is Geobacter, which is naturally found in many soils and sediments.
“Geobacter grows by breaking down organic materials and transferring electrons pretty much onto anything that looks like iron,” he said. “It's up in the top of the list in terms of generating high power densities.”
When attacking environmental pollutants such as aromatic hydrocarbons, Geobacter can break down some 90 percent, Lovley said. All in all, systems incorporating Geobacter can recover up to nearly all the electrons within sewage.
Although wastewater could essentially serve as a free source of fuel, wastewater alone cannot solve the energy crisis, Logan noted. If animal, food industry and domestic wastewaters were combined together, they could provide roughly 500 trillion BTUs of energy - an impressive figure, until compared with the roughly 100,000 trillion BTUs of energy the United States uses every year.
(Source: LiveScience.com)