FIG. 1.

Effect of the algQ mutation on pyoverdine yields in iron-depleted cultures of P. aeruginosa PAO1 carrying a single copy of algQ and multiple copies of algQ, ndk, pvdS, or rpoD. Bacterial growth in DCAA was monitored by measuring the absorbance at 600 nm of the cultures at different times. At each time, pyoverdine_PAO1 levels were determined by measuring the absorbance at 405 nm of cell-free culture supernatants diluted 1:2 in 100 mM Tris-HCl (pH 8.0). Data are expressed as relative fluorescence levels (A₄₀₅/A₆₀₀). All measurements were performed in duplicate and in multiple experimental trials with different batches of DCAA. The standard deviations are <8% of the values.