© Time-lapse movie by Dr. Remco Kort—published in J. Bacteroi. (2006) 188:3099-109.
Individual bacteria moving through a liquid solution in a microbiology lab often resemble the gas shown in Unit 9, Figure 6. In real life, however, these microorganisms form films on a surface, exhibiting striking collective behavior. In these communities, cells form organized three-dimensional structures like the ones shown developing in this movie of the four-day growth of a Bacillis subtilis biofilm. In order to form these films, which are essentially cities of bacteria, the cells must somehow sense multiple environmental and physiological signals and coordinate their movements.