Microorganisms could be responsible for the formation of some gold deposits, Lovley suggested. Traces of gold found in sediment in the southeastern United States, for example, may have been formed on the bottom of the ocean, near hydrothermal vents, millions of years ago.
Since the research was published in the July issue of Applied and Environmental Microbiology, several gold miners have approached Lovley to inquire about using the microbes in their operations.
Lovley isn't encouraging. Although dissolved gold is found in all water, even seawater, the use of these microbes to harvest gold does not make economic sense, he said. "You couldn't use this process to harvest the gold from the ocean. The cost in pumping the water would be more than how much gold you could recover," he said. The gold particles excreted by the microbes are so tiny it would take about a million microbes to produce a gram of solid gold.
Nonetheless, the gold industry thinks the research is worth watching, said Paul Bateman, executive director of The Gold Institute in Washington, D.C.
"Anything that will increase the yields in production at low cost would be of interest, but this is in the early stages of experimentation," he said. "There could be at some point an application where we use microbes like this to capture some gold particles lost in the processing of gold."
The new research finding, Lovley noted, is another line of evidence that microbes play a large role in formation of the environment. Previous research in his lab showed that massive accumulations of magnetite created by iron-reducing microbes during the pre-Cambrian period are now important deposits of iron ore.
"I'm not surprised that microbes are playing a role here, too," said Lovley. "It is interesting how research in one area can lead to different corners. That is the exciting thing about science."
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