For anyone suffering from cystic fibrosis or AIDS, the bacterium Pseudomonas aeruginosa is bad news. While the organism is found everywhere--including in sediment on the ocean floor--it can cause lung infections in those with weak immune systems. Researcher Dianne Newman of the California Institute

Newman's approach toward the microbe is to exploit the manner in which the organism must generate energy through electron transfer reactions in order to survive. Scientists know the fine details of electron transfer about a few proteins involved in cellular energy generation, but not about the processing of redox-active small molecules produced by an organism such as Pseudomonas aeruginosa. Progress could lead toward new insights about the function of these molecules in biofilms.

A possible outcome of the research would be the demonstration that electron shuttles work in such a way that the human pathogen Pseudomonas aeruginosa could be attacked through rational drug design. In other words, new drugs might be created specifically to interfere with the way that electrons move around in the course of the bacterium's doing what it needs to do to remain alive. Such a drug would be a new type of antibiotic. "It's hard to treat these bacterial infections with conventional antibiotics," Newman says. "Hopefully, we can learn something about what these organisms need to live, and can develop a new way to interfere with it."

Moreover, because the Pseudomonas aeruginosa bacterium has been found in significant numbers in biofilms developing on marine cathodes, the fuel cell possibly could be designed in such a way that the organism's life functions could be tapped to catch the energy from the current flow. Such a fuel cell would work like an underwater battery, with the bacteria ultimately providing a source of current by carrying on their life processes.