Bacteria 'wires' conduct electrons distances :
A newly discovered bacterium living on the bottom of the sea transports electrons over distance of few centimeters , so it can feed on hydrogen sulphide in low-oxygen environments. That is the scientists in Denmark and US, who have shown that thousands of the micro-organisms form filament with one end embedded in ocean sediments and the other end poking out into seawater. Understanding just how these organisms move electrons could lead to alternative technologies for generating energy.
Biologists have known for some time that the Desulfobulbaceae family of bacteria power themselves by consuming sulphur compounds in ocean sediments. However, this produces hydrogen sulphide, which is toxic at high concentrations. While these bacteria can consume hydrogen sulphide, this must be done in the presence of oxygen in a reaction that involves the transfer of an electron.
Ocean sediments normally have very low oxygen levels and studies have shown that when Desulfobulbaceae are present, sulphide levels increase steadily. But then something unexpected happens and sulphide levels drop quickly as if the sediments have experienced a rapid influx of oxygen. The problem is that the drop is so fast that it cannot be explained by the diffusion of oxygen molecules from the seawater above. Instead, scientists had thought that the many different species of Desulfobulbaceae bacteria in the sediment were working together to move electrons from oxygen-poor regions up to the seawater, where oxygen is plentiful.
