Development of a genetic tool for activating chromosomal expression of cryptic or tightly regulated loci in Pseudomonas aeruginosa

A method for replacing endogenous promoter by a constitutive promoter in Pseudomonas aeruginosa is described. Plasmid pKNG101, a broadly used shuttle suicide vector in P. aeruginosa, was improved to allow chromosomal introduction of a Plac promoter in front of any kind of gene especially those with unknown function. Using this strategy alleviates the need for cloning difficulties encountered in this bacteria and antibiotic marker selection.

► Any endogenous promoter replacement by a constitutive Plac promoter in Pseudomonas aeruginosa. ► The development of two shuttle suicide vectors derived from pKNG101 vector. ► pKNG202–Plac validation for expression of pil locus encoding a type IVb pilus.