FIG. 5.

Survival in response to toluene shocks of the wild-type P. putida DOT-T1E and mutant derivatives lacking toluene efflux pumps. Cells were grown in 30 ml of LB medium alone (circles) or LB medium with toluene in the gas phase (triangles) until the culture reached a turbidity of about 1 at 660 nm. These cultures contained about 10⁹ CFU/ml. The cultures were divided in two halves; to one we added (0.3% [vol/vol]) toluene (solid symbols), and the other was kept as a control (open symbols). The number of viable cells was kept as a control (open symbols). The number of viable cells was determined before toluene was added and 15, 30, and 60 min later. Top left panel, P. putida DOT-T1E; top right panel, P. putida DOT-T1E-1; bottom left panel, P. putida DOT-T1E-18; bottom right panel, P. putida DOT-T1E-82.