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Killing Superbugs from Within


A common moth may hold the key to antibiotics that destroy bacteria from within, short-circuiting their ability to resist. Most antibiotics mount an outside attack, but over time bacteria can evolve new defenses, giving rise to superbugs. Moths take a different approach. University of Pennsylvania professors Paul H. Axelsen and Jeffrey N. Weiser say these insects produce a protein that slips inside a bacterium, taking control of its genes and ordering it to die.

The protein, called Cecropin A, is produced by the caterpillar of the Cecropia, or silkworm moth. Like all insects, it doesn't have an immune system. Instead, it relies on self-produced antibiotics, such as Cecropin. The protein has intrigued scientists ever since it was identified in the 1980s, but no one was sure how it worked.

Axelsen and Weiser treated E. coli bacteria with nonlethal doses of Cecropin and discovered that the protein altered some 26 of E. coli's genes. "It's a whole different mechanism by which to kill bacteria," says Axelsen. Eventually, he says, drugs could be developed that work the same way, creating new and, with luck, resistance-proof antibiotics. Gasoline, plastics, and other necessities might not be possible without catalytic reactions. And materials called zeolites are among the most important catalysts in any chemical toolbox. Inside the tiny holes that riddle zeolites, molecules get crammed together so tightly that catalytic reactions happen with amazing speed. Pharmaceutical companies wish they could make more use of zeolites for refinement and production of drugs. But the holes are too small--less than 1 nanometer in diameter--for many drug molecules to enter.

Enter four new families of porous materials developed by chemists at the University of California in Riverside. Like zeolites, they can be made with uniform hole sizes--only larger. That could open the way to brand new biochemical production methods. And because the materials developed by researcher Pingyun Feng and her team include semiconductors such as gallium and germanium, they may also lead to new electrochemical sensors. Stars twinkle because their light gets distorted by shifting currents of turbulence in the air. In the time-exposure photos astronomers take, that romantic sparkle turns into confounding blurs.

To de-twinkle stars, astronomers have been installing adaptive optics systems since the late 1990s. The technique uses a computer to monitor the amount of atmospheric distortion and instantly counteract each twinkle by changing the surface of a flat, thin-film mirror. But these deformable mirror lenses are small--only a few inches in diameter--and require an external processing step that degrades images slightly.

Now, optics researchers led by the University of Arizona's Michael Lloyd-Hart have created the first dome-shaped, flexible glass mirror. It's also big--more than two feet across--and because of its size and shape, it can be installed inside the telescope. Initial tests at the observatory on Mount Hopkins, Ariz., indicate that large mountain-top telescopes fitted with such mirrors may soon be taking sharper photos than the Hubble Space Telescope.

Developing a curved-glass surface that can flex rapidly took years of work. One key: The glass is ground very thin, to less than two millimeters (0.08 inch). But the breakthrough may eventually put a twinkle in the eyes of consumers. University of Rochester researchers hope to use adaptive optics to improve eyeglasses. -- Small cotton farmers in developing countries could soon get a big boost from genetic engineering. A research team from Germany's University of Bonn and the University of California at Berkeley report in the Feb. 7 issue of Science that farmers in India harvested at least 80% more cotton when their crops contained a gene from Bacillus thuringiensis. This bacterium is a natural enemy of three species of bollworms, or moth larvae, that annually devastate more than half of India's cotton fields.

-- When the hydrogen economy finally kicks off, sources of the new fuel may not be hard to find. Many food-processing plants can produce it. Environmental engineers at Pennsylvania State University have shown that commercial quantities of hydrogen and methane can be wrung from the wastewater streams at plants that make potato chips, candy, and apple sauce. At each of three plants studied, the addition of bacterial spores could produce hydrogen and methane worth $80,000 a year. Extracting these gases would also slash wastewater-treatment costs by at least 20% and as much as 80%.


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