Fig. 5

Pellicle formation is delayed in PA14ΔhepP. Overnight growth of PA14, PA14ΔhepP, and PA14ΔzbdP was subcultured into fresh LB broth to a starting OD₆₀₀ of 0.02. Three-mL aliquots of the inoculum were dispensed into 17 mm × 100 mm polystyrene tubes and the tubes were incubated under static conditions at 37 °C for 24 h or 48 h. Pellicles are visible at the air-liquid interface in the tubes containing PA14 and PA14ΔzbdP at 24 h and with all three strains at 48 h (red arrowheads). Turbidity is present in the medium under the pellicles in the tubes containing PA14ΔhepP at 24 and 48 h (yellow arrowheads), while the turbidity clears from the medium in the tubes containing PA14 and PA14ΔzbdP at 48 h