Nature:
Pili, which are hairlike filaments that sprout from some
bacteria, can enable the bacteria to remove uranium from
contaminated groundwater without becoming poisoned in the
process.
Geobacter sulfurreducens, for example, obtains energy
by reducing, or adding electrons to, metals in the environment;
when pili are present, the bacterium is able to do this outside
the cell envelope. In addition to keeping uranium out of the
bacterium itself, pili provide a greater surface area for
electron transfer, increasing the amount of uranium removed.
Gemma Reguera of Michigan State University, who participated in
the
discovery,
is most excited about the possibility of developing nonliving
nanowires that share the pili's properties of electron
transfer. Such devices could be used in environments where
bacteria can't live, such as the Fukushima Daiichi plant in
Japan. It's possible that conductive nanowires could also be
used to remove radioactive isotopes of plutonium or
cobalt.
