Bacterial Breakthrough Could Lead to Cheap, Renewable Bio-Batteries

You may not think twice about what goes down the drain in your toilet. But soon, what you're flushing away could turn on the lights in your home.

This unique take on recycling comes from a substantial discovery concerning the way in which bacteria transfer electrical charges -- and it could lead to the development of “bio-batteries” or bacteria-fueled electrodes. Eventually, these fuel cells could take human or animal waste and convert it into usable energy.

“The exciting thing is that we really never understood how the electrons were getting on the surface,” Dr. Tom Clarke, one of the lead researchers on the project from the University of East Anglia, told “What happens in this process is that bacteria take in organic carbon molecules and ‘chew’ them inside the cell, which then releases electrons.”

The project -- funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and the U.S. Department of Energy -- has revealed how the microscopic molecular structure of bacteria proteins allows for energy transfer.

Multiple layers of proteins inside bacteria essentially act as the cell’s organic power lines, enabling electrons produced within the bacteria to be transferred to the bacteria’s surface. Now that scientists understand what’s happening on the surface, they will be able to produce a cell that can connect to the bacteria.

Then the bacteria can feed off the electrode, and in return, generate electrons.

The process is called iron respiration, but the researchers have colloquially dubbed it "breathing rocks."

“Bacteria have a whole different arsenal of things to breathe other than just oxygen. They can breathe on mineral oxides, so this process of bacteria sitting on rocks and breathing rocks can be applied to electrodes. Bacteria can breathe on the electrodes and produce electrons.”

There have been attempts to harness electricity on the surface of bacteria before, but lacking the knowledge discovered in this project, only small amounts of energy were able to be obtained. Now sizable amounts of electricity can be put towards practical use.

“It offers a very nice method of getting ecologically sound energy,” Dr. Clarke told “You can build these electrodes into places such as waste treatment plants. The bacteria can digest waste material and produce energy.”

Along with running an everyday generator, the discovery could also aid in the cleanup of pollution caused by oil or uranium. And the overall benefit -- the bacteria being used for the electrodes -- is both plentiful and renewable.

“One of the advantages of the bacteria we’re looking at is they're found everywhere already,” Dr. Clarke told “They actually live in the ground or in very common places. If you look at a lot of the names of what we’re considering, they’re in every single lake already.”

“All we would be doing is changing the surface that they live on,” he said.