Effect of toluene on the growth of P. putida strains. (A) Overnight LB medium cultures were diluted in the same medium with toluene in the gas phase, and growth was monitored by measuring turbidity. The strains used were DOT-T1E (○), the ΔtodC single mutant (▵), the ΔtodCpobA double mutant (□), and two derivatives of ΔtodCpobA carrying tmo/pcu genes in the chromosome, DOT-T1E-24 (⋄) and DOT-T1E-1-10a ([ast]). (B) Same as panel A except that glucose-supplemented M9 minimal medium was used instead of LB medium. The appropriate antibiotics were added to the cultures. OD 660 nm, optical density at 660 nm.