FIG. 2.

Transcription of sodA in mid-log-phase and stationary-phase cells of PAO1, PAO-JP1, and PAO-R1 as affected by iron limitation. Relative transcription levels were determined by measuring the reporter enzyme β-galactosidase as described by Miller (38) in planktonic cells harvested at mid-log (6 h) and late stationary (16 h) phases. Open bars, cells grown in TSB; filled bars, cells grown in TSB containing the iron-specific chelator 2,2-dipyridyl. The data represent the mean of three independent experiments (two to three cultures per experiment). Where visible, error bars denote 1 standard error.