Living Power Cables Made from Bacteria_Featured_, Science, Technology Monday, October 29th, 2012
(Discovery News) Three years ago, scientists discovered electric currents running through the seabed — but they had no idea what was causing them. But now, researchers from Denmark and the United States believe they have the answer: bacteria that function as living electrical cables. In a remarkable case of biological engineering, scientists have confirmed that each tiny section of the bacteria contains a bundle of insulated wires that leads an electric current from one end to the other.
According to Nils Risgaard-Petersen, Christian Pfeffer, and their colleagues at Aarhus University, they started to suspect that something was up when they noticed the appearance of a previously unknown type of long, multi-cellular bacteria. These bacteria were always present when electric currents were around. Moreover, they could disrupt the currents when they pulled a thin wire through the seabed — a possible indication of broken connections.
Looking at it more closely, they noticed that the bacteria, which is a hundred times thinner than a human hair, contained nanoscale strings that were enclosed by a membrane. They concluded that the entire organism functions as a virtual electric cable — insulating wires and all. And indeed, the researchers note that the structure is very similar to the electric cables that we use on a daily basis.
Image: Mingdong Dong, Jie Song and Nils Risgaard-Petersen