Using bacteria to make energy from waste

Learn about using bacteria to make energy from waste.

Bruce Rittmann: There’s a tremendous amount of biomass out there in the world that’s going untapped, a huge renewable energy resource.

That’s Bruce Rittmann with the Biodesign Institute at Arizona State University. He and his colleagues are working on using bacteria to produce energy from the organic waste materials all around us.

Bruce Rittmann: Now we can get electrons out of organic material, put those electrons into the anode of a fuel cell and then the rest of the fuel cell works. So we get combustion-less, pollution-free electricity.

Rittmann said that as this technology develops, microbial fuel cells could tap into a vast source of renewable energy.

Bruce Rittmann: There’s a very large amount of biomass out there. If you look at it worldwide, if we could collect all the residual biomass waste materials –unused agricultural materials, things like that — capture them and convert them to electricity this way, we could meet something like 25% of the world’s current energy demand.

He said microbial fuel cells are in an early stage of development. But these scientists believe this technology will one day help decrease our dependence on fossil fuels.

Bruce Rittmann: So if we can get microbial fuel cells to work we can generate out society’s most valuable energy source, electricity, from renewable sources and without pollution, so it’s really the ideal way to go.

Rittmann explained that, in working with the development of any fuel cell, researchers are trying to take something that is, as he says, ‘rich in energy and electrons.’ The researchers try to extract the energy and electrons out without creating combustion.

A microbial fuel cell is a special class of fuel cell. It contains a biological film called a ‘biofilm’ that actually lives within the fuel cell.

Bacteria in the biofilms within fuel cells are useful because they have the ability to metabolize organic material. Some of them can actually transfer electrons to the anode of a fuel cell. The organisms that can do that are the key to the success of this technology.

Microbial fuel cells are capable of removing electrons from a large range of organic materials. ‘That’s what microorganisms do to do live,’ said Rittmann. Some of bacteria are capable of transferring electrons to an anode of a fuel cell, so that you get combustion-less, pollution-free electricity.

Furthermore, the organic material can come from biomass, giving humanity an alternative to petroleum and other nonrenewable energy sources.

*Our thanks to:*
Dr. Bruce Rittmann, director of the Center for Environmental Biotechnology in the Biodesign Institute at Arizona State University, is an international leader in the use of microbial communities to provide services to society. Those services include pollution clean up, treatment of water and wastewater, capture of renewable energy, and directly improving human health. Dr. Rittmann was elected to the National Academy of Engineering in 2004. He is a Fellow of the AAAS, a recipient of the Clarke Prize for Outstanding Achievement in Water Science and Technology, a winner of the Huber Research Prize from ASCE, and one of the world’s most highly cited researchers, according to ISI.