Bacteria that make gold? Kind of...

Let the Midas and Goldfinger jokes abound: CNN is reporting that scientists believe they have found a microorganism capable of contributing to the formation of gold nuggets.

If there's gold already present, the bacterium known as Ralstonia metallidurans can make more, according to the team led by Frank Reith. The scientists came to this hypothesis while investigating gold grains from two mines in Australia, and consider it the strongest evidence yet that gold nuggets may owe their growth in part to microorganisms.

Several researchers are experimenting with naturally occurring, and genetically enhanced, microbes as tools in chip production, hydrogen production, pharmaceutical design and the making of methane.

Like the ones found in Australia, some researchers are finding that some microbes are attracted to, and will consume, materials with metals mixed in. The microbes produce proteins that interact with these materials and cause chemical reactions.

Food processors and drug makers have relied on microbes to secrete proteins, but the end products were the proteins. Now, the proteins are being used as tools. "The first incarnation was where the protein was a product," said Jim Swartz, a professor of chemical engineering at Stanford University who has also founded a company called Fundamental Applied Biology. "Now we have entered a phase where the protein isn't the product, but a means to an end."

Additional reporting by Michael Kanellos.