PMC

Biofilm formation of the wild type (WT), pelA mutant, and QS mutants (lasI and rhlI mutants) of P. aeruginosa PA14. (A) Colony morphologies. (B) CV staining of the solid-surface-associated biofilm. The control was medium alone.

Thermoregulation of pel transcription and biofilm formation in P. aeruginosa PA14. (A and B) β-Galactosidase activities of the pel promoter-lacZ transcriptional fusion in the wild type (WT) and QS mutants (lasR and rhlR mutants) at room temperature (A) and at 37°C (B). (C) CV staining of the solid-surface-associated biofilm at room temperature (solid bars) and at 37°C (open bars).

Requirement of QS in pelA transcription and wrinkled-colony formation in P. aeruginosa PA14. (A) β-Galactosidase activities of the pel promoter-lacZ transcriptional fusion in the wild type (WT) and QS mutants (lasI, lasR, rhlI, and lasI rhlI mutants). (B) β-Galactosidase activities of the pel promoter-lacZ transcriptional fusion (top panel) and colony morphologies (bottom panel) of the wild type and the lasI mutant in the presence of 10 μM 3-O-C₁₂ homoserine lactone (3OC₁₂). The promoter-less lacZ construct was used as a control. N.A., no autoinducer added; EA, ethyl acetate-glacial acetic acid (1,000:1, vol/vol).