Figure 1. Influence of pstS and phoB deletion on swarming motility.

PAO1, ΔpstS, ΔphoB and ΔpstSΔphoB carrying an empty vector (pUCP18Ap) or a complementation plasmid (ppstS and pphoB) were grown for 24 hours at 37°C on swarming plates containing M9 (20 mM) or phosphate-depleted M9 (0.2 mM) as described in Materials and Methods.