Fig 3. Expression levels of nahH and pheB and specific activities of C23O in strains C70 and C70ΔpheB on different growth substrates.

(A) For qRT-PCR analysis of the mRNA transcripts, the cells were grown on R2A medium, R2A and phenol (PHE, 2.5 mM), R2A and salicylate (SAL, 2.5 mM), or R2A and the mixture of SAL and PHE. The relative expression ratios (y-axis) were calculated as relative values of the reference gene polA expression level of the respective C70 strain. (B) Specific activities of C23O of the wt and C70ΔpheB strains were determined from cells grown on minimal medium supplemented with phenol, salicylate or the mixture of them (all substrates 3 mM). Samples were taken from the middle (I or no specification) or the late-exponential (II) growth phase.