Group of Microbes Change Dissolved Gold to Solid
option8 writes " National Geographic, has a an article about a newly discovered strain of bacteria that might be used (though, as the article says, not cost-effectively) to harvest gold and other metals from seawater - a longtime fantasy of science fiction."
The microbes might not be economically viable at extracting gold from seawater, but that doesn't mean that they're useless. A clever engineer could probably figure out a way of using the microbes to cheaply process low grade ore. That's currently done using environmentally dangerous processes like cyanide heap leaching (which is as dangerous as you'd expect a process using large amount of cyanide to be) but a microbe that has an affinity for gold could make that type of work much safer and more environmentally friendly. Yes it would take quite a bit of work, but gold is still valuable enough that people are likely to look into it.
There's no point in questioning authority if you aren't going to listen to the answers.