MicrobeWorld App


Microbes After Hours


Click for more "Microbes After Hours" videos

Join MicrobeWorld

Subscribe via Email


Featured Image

Featured Video

Ebola Virus explained


ASM House 200X200

Flagellum failure lets bacteria turn

When headed the wrong way, some bacteria turn by letting their propellers flop.

The newly discovered turning mechanism explains how a marine bacterium can control its direction using only a single flagellum, a stiff, rotating appendage that propels the cell forward. Turning depends on a mechanical characteristic that engineers might consider a failure if the flagellum were human-made: the tendency of flexible materials to buckle under pressure.

A multiflagellated bacterium like Escherichia coli turns by releasing one flagellum from a spinning bundle, which unwinds and sends the cell tumbling in a new direction. But 90 percent of mobile marine bacteria have only one flagellum each. In the past, scientists thought that these one-prop microbes could swim only in a straight line, says coauthor Roman Stocker of MIT. Then in 2011, a team led by Xiao-Lun Wu of the University of Pittsburgh Medical Center showed that the single-flagellum bacterium Vibrio alginolyticus can make sharp turns. To change course, the cell backs up a little and swings its flagellum to one side, like a boat rudder.

Comments (0)

Collections (0)


American Society for Microbiology
2012 1752 N Street, N.W. • Washington, DC 20036-2904 • (202) 737-3600
American Society For Microbiology © 2014   |   Privacy Policy   |   Terms of Use