IMAGINE having 15-metre-long arms that you could use to pluck fruit off trees. Some bacteria have an equivalent ability: they can make “arms” 10 times their own length to help them process nutrients.
The Geobacter family of bacteria live underground. They get their energy by oxidising organic molecules such as oils, a process that involves stripping electrons from the organic molecules and dumping them onto iron oxide crystals around them. But the crystals do not dissolve in water and hence cannot be absorbed by the microbe. They can also be quite far away. So how do the bacteria make…
