January 1, 1970 (Vol. , No. )
In a story that almost sounds science fictional, researchers at the University of Minnesota reported in today’s issue of the Proceedings of the National Academy of Science that they have found the key to an unusual bacterium’s ability to produce electricity. The answer? It seems that vitamin B-2, also known as riboflavin, is essential and responsible for most of the organism’s properties, which include converting lactic acid into electricity. The finding may energize alternative energy production and cleanup of toxic waste sites, among other applications. The bacteria, known as Shewanella, manipulate iron in their native aqueous environment, helping to solubilize it and they play important roles in the movement of the metal in the ecosystem. To do this, they require a source of electrons, but researchers Daniel Bond and Jeffrey Gralnick at the University of Minnesota’s Biotechnology Institute were initially mystified as to how the microbes accomplished their magic. However, upon discovering that Shewanella growing on electrodes produce riboflavin, the final piece of the puzzle came into place. Riboflavin, it seems, carries electrons from the cells to the electrodes. In the presence of riboflavin, rates of electrical production increased 370%. Researchers envision Shewanella bacteria could become components of living fuel cells that, when amassed, could be used to power remote sensors and even clean wastewater. They also speculate it might be possible to reverse the solubilization process the organisms normally stimulate, thus preventing the corrosion of iron and other metals on ships.