Page "Flagellum" Paragraph 18

Different species of bacteria have different numbers and arrangements of flagella.

Monotrichous bacteria have a single flagellum ( e. g., Vibrio cholerae ).

Lophotrichous bacteria have multiple flagella located at the same spot on the bacteria's surfaces which act in concert to drive the bacteria in a single direction.

In many cases, the bases of multiple flagella are surrounded by a specialized region of the cell membrane, the so-called polar membrane.

Amphitrichous bacteria have a single flagellum on each of two opposite ends ( only one flagellum operates at a time, allowing the bacteria to reverse course rapidly by switching which flagellum is active ).

Peritrichous bacteria have flagella projecting in all directions ( e. g., E. coli ).