Biorefinement of soluble gold

Andy Coghlan, at New Scientist:

Delftia acidovorans ... has evolved a chemical that detoxifies gold ions by turning them into harmless gold nanoparticles. These accumulate safely outside the bacterial cells.

Very cool!  One of the discoverers, Nathan Magarvey, of McMaster University in Canada thinks that the protein responsible could be used to create sensors capable of detecting gold ions in groundwater.  It wouldn't exactly extract much gold but it could provide an inexpensive method of prospecting by taking water samples.