With some creative genetic engineering, chemists have designed bacteria that rely on a breakdown product of caffeine for their survival. The advance could eventually lead to decaffeinated coffee plants, the researchers suggest.
"The idea is to convince these microorganisms to do the chemistry that we want them to do," says Justin Gallivan, a chemist at Emory University in Atlanta. He and Shawn Desai, also of Emory, provided bacteria with a molecular switch that senses the presence of theophylline—the caffeine by-product. In response, the switch activates a gene that renders the microbes resistant to an antibiotic.