With this staining procedure, the vegetative bacteria stain blue and the endospores are colorless. Observe the demonstration slide of Clostridium tetani . With this staining procedure, the vegetative bacteria stain blue and the endospores are colorless. Most motile bacteria propel themselves by special organelles termed flagella . The rotation of the inner disk causes the flagellum to act much like a propeller.
Bacterial motility constitutes unicellular behavior.
In other words, motile bacteria are capable of a behavior called taxis. Taxis is a motile response to an environmental stimulus and functions to keep bacteria in an optimum environment. The arrangement of the flagella about the bacterium is of use in classification and identification. One group of bacteria, the spirochetes , has internally-located axial filaments or endoflagella. Axial filaments wrap around the spirochete towards the middle from both ends.