Motility Test
The purpose of this test is to determine whether an organism is motile at a given temperature. The medium used is semi-solid. Motile bacteria migrate from the stab and diffuse into the medium causing turbidity, whilst non-motile bacteria show growth confined to the stab line. 1. Uninoculated medium. 2. Motile: Shewanella. The diffuse growth has spread from the stab line to about 1.5 cm from the bottom of the tube. 3. Non-motile: Acinetobacter. 4. Non-motile: Klebsiella. In some cases Klebsiella bacteria may produce so much gas that bacteria are dragged away from the stab line by gas bubbles, causing the growth pattern in the medium to be similar to a pine tree. This phenomenon is not seen in this example.
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