Fig. 6

Development of comet and disk clusters from a single or a bundle of filaments. a-f. Schematic representation of the transition of colony patterns. Bacterial filaments and possibly secreted mucilage are shown in brown and pale blue, respectively. Spontaneous bending of a protruding filament in a bundle (a, upper) or collision of two single filaments crossing paths (a, bottom) leads to the formation of a “top covered” bundle (b) which is a precursor to a comet-like wandering cluster. Collision of comets (c) and propagation of cells enlarge the size of comet-like clusters (d). Change in the direction of the movement (e) can spontaneously lead to a self-following orbit, which develops into a rotating disk (f). Detachment of filaments and collision-based decay of the clusters also occur, leading to transitions from larger clusters to smaller clusters, bundle, or filaments. g-i. Time-lapse images of transitioning Pseudanabaena cluster patterns. g. Enlargement of comet-like cluster by collision of two comets. The video is provided in Movie S12. h. Transition from come-like wandering cluster to self-following orbit, developing into a rotating disk. The video is provided in Movie S13. i. Collision of a comet-like cluster (moving from the upper right to the center) to a rotating disk (center), leading to the collapse of the disk and reversion to a comet-like cluster. The video is provided in Movie S14