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Air Bacteria Census

January 17, 2007

Scientists are taking stock of all the bacteria that live in the air.


The first airborne-bacteria census. I’m Bob Hirshon and this is Science Update.

If there’s anthrax in the air, is it a bioterror weapon, or just a naturally occurring close relative? The Department of Homeland Security needs to know, so they asked scientists at Lawrence Berkeley National Laboratory to take stock of the air’s normal bacteria population. Microbial ecologist Gary Andersen says a better sampling technique was sorely needed.

GARY ANDERSEN (Lawrence Berkeley National Laboratory):
Virtually everything that has been done to date has used culture. And we know that less than 1 percent of all organisms that are in the air can be cultured.

Instead, his team used DNA microchips, which can identify thousands of bacterial species from a single gene. Their first local census found about 1,800 kinds of bacteria, including some that could be mistaken for bioterror agents. They also found that the bacterial population varies dramatically with the seasons and the weather. I’m Bob Hirshon, for AAAS, the science society.