Figure 3.

Deletion of hfq results in reduced c-di-GMP levels and biofilm formation. PA14 (A) and PAO1 (B) (blue bars) and the corresponding hfq deletion strains (red bars) harboring plasmid pCdrA::gfp(ASV)^c, carrying a c-di-GMP sensitive transcriptional cdrA-gfp fusion gene, were grown in SCFM to an OD₆₀₀ of 1.8–2.0. The analysis was performed as described in Materials and Methods. (C) Static biofilms of PA14 and PA14Δhfq were stained with crystal violet after growth in SCFM for 48 h. The stain was then eluted by ethanol and the absorption at 595 nm was measured. Representative pictures of the PA14 and PA14Δhfq biofilms are shown on top. The experiments were performed in duplicate. Error bars are given as standard deviation.