freshare.net
By Karen Kosko
02-29-2008In today’s edition of the journal Science, Louisiana State assistant professor Brent C. Christner reported his findings of significantly large numbers of bacteria in snow and rain.
Scientists have realized for some time that cold conditions in the upper atmosphere are where rain and snow form. They have long known that, in order to condense into liquid, the moisture must be able to cling to something. What moisture molecules cling to, scientists refer to as nucleators or nuclei.
Christner’s study shows that an extremely high percentage of these nuclei are bacteria.
Christner and his team took snow samples form the Antarctica, France, Monatna and the Yukon. Some samples showed that as much as 85 percent of the nuclei in them were bacteria. The highest percentages were reported in France, followed by Montana, the Yukon and Antarctica.
The study identified the most commonly occurring bacteria as Pseudomonas syringae, which is known to cause diseases in plants such as beans and tomatoes. While Pseudomonas syringae may be bad for some plants, it is, apparently, very good fro the atmospheric conditions necessary to produce rain.
The study was supported by a Louisiana State University research grant.