Movies of swimming motility

Escherichia coli

Rhodobacter sphaeroides

Synechococcus


Movies of swarming motility

Escherichia coli swarm

Salmonella typhmurium swarm

Serratia marcescens swarm


Movies of gliding motility

Cytophaga

Mycoplasma mobile

Flavobacterium johnsoniae


Movies of Twitching motility

Pseudomonas aeruginosa


Other movies

Tethered bacteria

Escherichia coli patterns

Carpets and microchannels

Miscellaneous movies

Marvels of Bacterial Behavior - History & Physics of Bacterial Motion



Rowland Institute         Harvard University
     
 

Swarming Salmonella typhimurium

When grown on soft agar (0.5-0.8%) and a rich medium, cells of Salmonella typhimurium (and other Gram-negative bacteria) elongate, produce more flagella, and move over the surface of the agar in a coordinated manner. Lipopolysaccharide (slime) appears to be important as a wetting agent. The chemotaxis system is required, but the cells need not respond to specific attractants or repellents. As you will see in the movies, the cells swirl about in rafts or packs. At the edge of the swarm they form a monolayer. At the very edge, cells are nearly stationary. Farther back, closer to the point of inoculation, cells pile up in multilayers and are very active. The videos were made in phase contrast.


Movies

Swarming at 2 hours incubation, center

Swarming at 2 hours incubation, edge

Swarming at 4 hours incubation, center

Swarming at 4 hours incubation, edge


Reference

Harshey, R. M. Bees aren't the only ones: swarming in Gram-negative bacteria. Mol. Microbiol. 13, 389-394 (1994).

We would like to thank Rasika Harshey for her help in creating these movies.