November 3, 2006 3:16 PM PST
Microbes could one day make airplanes safer
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Researchers at MIT have pinpointed microbes that one day could be capable of detecting stress points and small fractures on airplane wings and other parts, professor Angela Belcher said at a nanotechnology conference taking place here this week.
The genetically engineered microbes produce proteins that attach to specific metallic alloys, said Belcher, a professor of materials science and biological engineering who was awarded MIT's Germeshausen Professorship for combining humanitarian advancement with technological progress.
When stressed, a sheet of metal will slightly change into an alloy at the stress point, she said at the Semi NanoForum 2006 conference. Thus, by covering the wing with the microbes (and then removing the excess) human technicians can find the areas that are in greater danger of failure. The other end of the microbe is illuminated to make them easier to find, Belcher said.
The microbes have not been tested in real-world situations where dirt, grime and other factors can impede the effectiveness of the microbe. MIT has tested it on clean sheets of metal in optimal lab environments. Still, the results are "promising," Belcher said.
MIT researchers have also created a battery with microbes. The microbes create cobalt oxide wires (and another microbe has a gene that attaches a gold particle to the wire) at room temperature on a 10 centimeter by 10 centimeter sheet of plastic. Potentially, these virus-created batteries could be incorporated into the uniforms of soldiers or inserted inside someone's body.
Belcher is one of the key thinkers in the growing field of, for lack of a better term, industrial microbiology. Researchers are essentially taking the proteins generated by the genes of single-celled animals and then examining how these long molecules interact with other substances. Producing industrial chemicals, or products created out of them, now often requires furnaces, expensive equipment and lots of energy. Engineering microbes to do the same thing at room temperature could greatly reduce costs on making a lot of things as well as open the door to new types of chemical agents and medicines.
At Stanford University, for instance, professor Jim Swartz has found a microbe that splits water with sunlight. University of California, Berkeley's Jay Keasling has isolated a metabolic pathway in a plant that produces an antimalarial drug.
The microbes are being studied in their natural state and bred selectively for genetic enhancement. In the related field of synthetic biology, researchers are trying to replicate the process of producing proteins inorganically, i.e. without the animals.
Currently, most of the work remains in the experimental phase, and is mostly being funded by organizations like the U.S. Department of Defense. Still, the wider commercial potential is being tapped. Cambrios Technologies, founded by Belcher, has come up with a microbe soup that can possibly make it cheaper to add insulation layers in semiconductors. (Swartz and Keasling, meanwhile have founded, Fundamental Applied Biology and Amyris Biotechnologies, respectively.)
Next at MIT, scientists will examine ways to see if microbes can produce particles for solar cells, Belcher said. A project to find a microbe for colon cancer diagnostics is under way.
To date, Belcher and her students (some of whom have become professors at other universities) have mostly experimented with viruses. Viruses grow on bacteria. Yeast is now being tested out because it doesn't require a host organism, making it easier to breed.
"We think of yeast as an electric stem cell," he said.