Fig. 4. Reduced biofilm formation and production of pyoverdine on the CP55-60 surfaces.

(A) Absorbance measurements of the crystal violet staining and (B) SEM images of the biofilms after incubating for 24 hours with uncoated PVC and PVC coated with PDVB, underivatized CP55, and the CP55-60. Biofilms on CP55, PDVB, and PVC exhibited greater numbers of bacteria and thick and mature EPS structures, whereas the biofilms on CP55-60 grew to a less degree with sparse EPS. Scale bar, 20 microns. (C) Fluorescence measurements of the production of pyoverdine after a 24-hour incubation with uncoated PVC and those coated with PDVB, underivatized CP55, and the CP55-60. The fluorescence emission at 460 nm, representative of pyoverdine, was normalized by the OD₆₀₀ of the culture medium. Data are shown as means ± SD (n = 6).