Bacteria survive being zapped

That lunchroom advice has been put to the test by researchers who looked for bacteria inside microwave ovens and found a surprisingly diverse ecosystem that is resistant to the appliances’ heat. Microwaves work by causing water molecules inside food to vibrate, producing frictional heat that cooks the food and kills the bacteria it might contain. “It’s not the same thing to warm up fish or pasta, and then to warm up these tiny microorganisms that may be mixed with some fat in a very thin layer on top of this glass tray that is inside the microwave," said Manuel Porcar, a researcher at the University of Valencia and chief executive of Darwin Bioprospecting Excellence, a Spanish biotechnology firm. Lab microwaves—which are turned on for longer periods—were home to bacteria resistant to radiation and extremely high temperatures, similar to bacteria found living on solar panels or near nuclear waste sites.