FIG. 3.

Influence of the MexC-MexD-OprJ (A and B) and MexE-MexF-OprN (C) efflux systems on the growth of P. aeruginosa in the presence of organic solvents. (A and B) P. aeruginosa K1121 (MexCD-OprJ⁻) (○, •) and K1131 (MexCD-OprJ⁺) (▵, ▴) were grown in LB broth at 37°C to the early exponential phase, at which time (arrow) n-hexane (1% [vol/vol]; A, solid symbols) or p-xylene (0.1% [vol/vol]; B, solid symbols) was added and growth was determined by monitoring OD₆₆₀. (C) P. aeruginosa K1115 (MexEF-OprN⁻) (○, •) and K1117 (MexEF-OprN⁺) (▵, ▴) were grown in LB broth at 37°C to the early exponential phase, at which time (arrow) p-xylene (0.08% [vol/vol]; solid symbols) was added and growth was determined by monitoring OD₆₆₀. Growth of solvent-free cultures is represented by the open symbols in panels A, B, and C.