Discontinuous expansion linked to sector formation in Pseudomonas aeruginosa colonies

Colonies of Pseudomonas aeruginosa exhibit sectors that were shown to be lo cated at specific intervals within the colony. Maxima in the distribution o f sectors were observed every 5 mm as measured from the center of the colon y. These maxima correlated with changes in the expansion rates of colonies. The absolute average number of sectors per colony was higher for colonies grown at higher temperatures. These results increase our understanding of c olony pattern formation.