Briefly, mucoidy (from – [non-mucoid] to +++ [highly mucoid]) and colony size were assessed by growth on Columbia horse blood agar (Oxoid, Basingstoke UK) and Mueller-Hinton (Oxoid) agar. Pyocyanin production was scored against colour standards from overnight LB broth cultures grown at 37°C. For pyoverdine production, 5 μL of overnight LB culture was spotted on to a King’s B agar plate, allowed to dry and incubated for 24 h at 37°C, and assayed based on the zone of pigmentation around the colony. Rhamnolipid, phospholipase

C (PLC), PF-3084014 chemical structure haemolysin, total protease and elastase assays were conducted using 5 μL each of overnight LB culture spotted onto agar as follows: i) rhamnolipid, M9 agar; ii) PLC, egg yolk agar (Oxoid); iii) haemolysin, Columbia horse blood agar; iv) total protease, 10 mL skim milk agar; and v) elastase, 10 mL elastin agar. Each assay was incubated for 24-48 h at 37°C and the diameters of clearing zones measured. Each assay was conducted in at least triplicate. Biofilm HDAC inhibitor forming properties were measured using a 1:100 dilution of an overnight LB broth culture in fresh LB medium. 100 μL was added to each well of a flat bottom MicroTest tissue culture plate (BD, Franklin Lakes NJ) and incubated in a moist environment at 37°C for 24 h. Wells were stained with 200 μL 0.5% crystal violet for 3 h before dissolving in 200 μL 20% (v/v) acetone. Absorbance was then read at 620 nm.

Swimming motility was assayed by spotting a single colony onto a 0.3% LB agar plate and incubating for 24 h at 37°C. Twitching motility was assayed by stabbing a colony into the bottom of a 10 mL 1% LB agar plate and incubating for 24 h at 37°C. In both cases motility was measured by the diameter of the resulting growth zones. Preparation of protein extracts for 2-DE Proteins were extracted from 10 mg of lyophilized bacterial

cell pellets in 1 mL 40 mM Tris (pH 7.8) by tip-probe sonication (Branson, Danbury CT) using 4 cycles of 30 s with resting on ice between cycles. Nucleic acids were removed by incubation with 150 U endonuclease (Sigma, St. Louis MO) for 20 mins at room temperature. Lysates were then centrifuged at 12,000 × g for 15 mins at 15°C to remove insoluble material. Resulting supernatants were methanol precipitated overnight at -80°C Phloretin and the proteins collected by centrifugation at 12,000 × g for 30 mins at 4°C. Proteins were then resuspended in 1 mL of 2-DE buffer (5 M urea, 2 M thiourea, 2% [w/v] CHAPS, 2% [w/v] sulfobetaine 3-10, 40 mM Tris, 0.2% [v/v] carrier ampholytes, 0.002% [v/v] bromophenol blue and 2 mM tributylphosphine [TBP]). Separation of proteins by 2-DE Proteins (250 μg) were loaded onto 17 cm pH 4-7 immobilized pH gradient (IPG) strips (Bio-Rad, Hercules CA) by overnight passive rehydration. Isoelectric focussing was carried out using a Bio-Rad IEF Cell for a total of 80 kVh.