In a study that is shocking in more ways than one, microbiologists at UMass Amherst have found certain microorganisms that have the ability to generate electricity from organic matter found on ocean floors. In their experiments, the researchers used water and sediment samples from Boston Harbor, a couple of jars, two graphite electrodes and simple electrical wiring to understand the working of this sediment battery. While one electrode was inserted into the mud, the other was left in overlying water. The resulting current was strong enough to power a light bulb or even a computer. According to microbiologist Derek Lovley, who heads the research team, the findings have implications for many industrial and military applications.

The team, funded by the Office of Naval Research, has already identified a family of energy-harvesting microorganisms, called Geobacters, as being key to the production of electrical current. Unlike most life forms, including humans, that generate energy by combining commonly found organic compounds with freely available oxygen, Geobacters thrive in oxygen-deprived environments by ‘breathing’ iron present in the soil.

Lovley feels that an understanding of how the microbes generate and use electrical energy may prompt the development of new technologies to decontaminate polluted water and sediment containing organic materials, including petroleum and other aromatic hydrocarbons. In fact, some Geobacters are already known to convert toxic organic compounds such as toluene to electricity

A general idea of what the bacteria does is already known. The modus operandi comprises two stages. First a group of Geobacters team up to break down larger and more complex organic compounds to acetate. Then they transfer the electrons from the acetate to the electrode generating the electrical current. Though bacteria have been shown to produce electricity before this study, what makes the UMass findings unique is that this is the first time indigenous bacteria have produced electricity in natural conditions and without chemical stimulation.

UMass researchers are also studying the Geobacters’ genome and once that is known, the bacteria can be manipulated to make them receptive to a variety of organic or inorganic contaminants. “Theoretically, when they begin to degrade the contaminant they will throw electrons on an electrode, and that could set off an audio/visual or some other form of signal,” says Lovley.

An understanding of how this phenomenon operates has a number of extremely timely applications, especially in developing technologies to recognize toxins and organic contaminants. Lovley cites, for example, the potential for using such technology to develop military equipment that could alert soldiers to the presence of toxins or biological warfare agents in the immediate environment.