In research related to pollution clean-up, a team of UMass microbiologists led by noted researcher Derek Lovley has extracted gold solids from water containing dissolved gold. The work uses technology Lovley developed 10 years ago to clean up heavily polluted water and soil around the U.S. using bacteria and archaea, or ancient micro-organisms, to break down heavy metals in affected environments.
Like uranium, cadmium, and other heavy metals, gold is precious and useful to humans. Lovley notes that dissolved gold, however, is useless because it can't be manipulated and formed into objects of value or beauty. He says when either solid or liquid gold is ingested, it is toxic to most life forms. On the other hand, liquid gold and many other heavy metals are not toxic to a group of microbes called extremophiles, or simple life forms known to thrive in environments where others cannot live.
With this in mind, the UMass researchers asked if extremophiles might have ingested the liquid gold found in hydrothermal vents, hot springs, and other hot places, and left it scattered as deposits of solid gold in places that now are below the surface of the Earth. This would explain how the metal came to be in two different forms in very different environments. If that is the case, the team wondered if microbes could duplicate the process in the laboratory and extract valuable solids from liquid containing dissolved gold.
"A vast number of bacteria and archaea have the ability to transfer electrons to iron throug
Contact: Paula Hartman Cohen
University of Massachusetts at Amherst