Bacteria

Actinobacteria

Movement

Motile bacteria can move about, either using flagella, bacterial gliding, or changes of buoyancy. A unique group of bacteria, the spirochaetes, have structures similar to flagella, called axial filaments, between two membranes in the periplasmic space. They have a distinctive helical body that twists about as it moves.

Related Topics:
Flagella - Bacterial gliding - Spirochaete - Axial filament - Helical

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Bacterial flagella are arranged in many different ways. Bacteria can have a single polar flagellum at one end of a cell, clusters of many flagella at one end or flagella scattered all over the cell, as with Peritrichous. Many bacteria (such as E.coli) have two distinct modes of movement: forward movement (swimming) and tumbling. The tumbling allows them to reorient and introduces an important element of randomness in their forward movement. (see external links below for link to videos).

Related Topics:
Peritrichous - Random

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Motile bacteria are attracted or repelled by certain stimuli, behaviors called taxes - for instance, chemotaxis, phototaxis, mechanotaxis and magnetotaxis (Italian). In one peculiar group, the myxobacteria, individual bacteria attract to form swarms and may differentiate to form fruiting bodies. The myxobacteria move only when on solid surfaces, unlike E. coli which is motile in liquid or solid media.

Related Topics:
Stimuli - Chemotaxis - Phototaxis - Mechanotaxis - Myxobacteria

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