The Pel Polysaccharide Can Serve a Structural and Protective Role in the Biofilm Matrix of Pseudomonas aeruginosa
Figure 2
PA14ΔpelB is arrested in the monolayer stage of biofilm development.
Strains PA14 (A) and PAO1 (B) were compared at 24 h for levels of biomass in microtiter dishes grown at room temperature by measuring crystal violet binding OD595. Expression of the pel operon from an arabinose-inducible plasmid pMJT1 (Ppel) but not in the vector control (VC) alleviated the crystal violet staining defect of PA14ΔpelB. Biofilm structure was visualized in a flow cell and representative top-down and side-view images are shown for PA14, PA14ΔpelB and PA14PBADpel (C) and PAO1, PAO1ΔpelB and PAO1PBADpel (D). Images were obtained using a 20× objective after four d of growth in continuous flow chambers. Scale bars represent 100 µm. Error bars represent standard deviations.