Radial and Spiral Stream Formation in Proteus mirabilis Colonies
Figure 2
(A) The colony front and the patterning zone. (B) A vertical cross-section of the system.
The lower layer is hard agar that contains nutrients, and the top layer is slime generated during colony expansion. Swimmers move in the layer of slime, absorb nutrients that diffuse upward, and secrete attractant. Bacterial flagella are not shown.