【英语时差8,16】平流层的细菌（在线收听）

Stratospheric Bacteria D:Nice telescope,Yael,what are you looking at? Y:Bacteria. D:In space? Y:Not that far out,Don.Scientists recently collected three brand new species of bacteria from the Stratosphere. When I heard about it,I couldn't believe it.Researchers have been using balloon lifted cryosamplers to collect bacteria and fungi from the stratosphere for years. D:I didn't think that anything can live that high in the amosphere. Y:Neither did I.The stratosphere extends from ten to thirty miles above the surface. That’s above the clouds where temperatures can get as cold as minus 76 degrees Fahrenheit, and there’s lots of ultra violet radiation. D:So How do they think bacteria got up there? Y:Some scientists think they ride up on particles ejected from volcanoes. Others think bacteria might be sucked through updrafts caused by a special kind of lightning that travels upwards from cloud tops.Forest fires can also cause thunderstorms that toss immense plumes of smoke into the stratosphere. Bacteria could ride on the soot. D:And they are the same kind Of bacteria that live here on the surface? Y:Some are known species. They have found rod-shaped Bacillus that are very common here as well as Staphylococcus species related to disease causing bacteria.Others are completely new, including two new Bacillus species. There’s also a third group of bacteria found in clumps that can’t be cultured in normal bacterial nutrients. So far, they are a puzzle. D:That's really out of this world,Yael.But you really are trying to see bacteria with your telescope,are you? Y:No,Don.They are away too small. I'm just out enjoying the stars.