The Pel Polysaccharide Can Serve a Structural and Protective Role in the Biofilm Matrix of Pseudomonas aeruginosa
Figure 5
Pel is important for cell-to-cell interactions necessary for aggregate formation.
Laser tweezers were used to trap bacteria and investigate bacterial clumping phenotypes. The captured bacteria were examined visually by light microscopy for aggregation after 20 min (A) PA14 (B) PA14ΔpelB. An extended trapping time of 45 min was required to initiate aggregation in PA14ΔpelB (C). The stability of formed aggregates was visually assessed five min after the release of the laser trap (center panel A and C). Aggregate stability was classified into three categories, “stable” if the aggregate remained intact, “unstable” if the aggregate dispersed into single cells and “none” if an aggregate did not form during the allotted time (right panels). A minimum of six replicates for each strain was assessed. Scale bars represent 10 µm. Representative phase-contrast images are shown.