Danish scientists from Aarhus University have discovered bacteria in the seabed that function as living power cables. They exchange electrons with other bacteria, as far as 1 centimeter away. The findings were published in Nature on October 24.
The bacteria was first detected in 2010 by microbiologist Lars Peter Nielsen who was studying the mud upon the sea floor in the port of Aarhus. Nielsen discovered a seemingly inexplicable electric current in the undisturbed sea bed. Since then, Nielsen’s team has partnered up with the University of South California to find an explanation as to how and why this is happening. At the time they speculated that the electric currents might run between different bacteria via a joint external wiring network. After studying the sediment they discovered that there are tens of thousands of kilometres of the bacteria underneath the sea floor.
It was Nielsen’s student Christian Pfeffer, that recently found that the electric mud abounds with a new type of bacteria which align themselves into living electrical cables. Each one of these ‘cable bacteria’, is a hundred times thinner than a human hair and contains a bundle of insulated wires that conduct an electric current from one end to the other. The bacteria belong to a microbial family called Desulfobulbaceae. The cable bacteria stretch out from the deeper mud where there is no oxygen, towards the surface which has plenty of oxygen. Because the bacteria are joined into one long filament, the cells at the bottom can feed themselves with sulphur from the mud on the sea bed while getting oxygen from above.
The scientists are now investigating how the cable bacteria function at the molecular level. According to them, the discovery of these unique bacteria could also lead to a better understanding of the development of life on Earth.