Stability assays of TodS and TodT. Pseudomonas putida DOT-T1E cells were grown on minimal medium with glucose. When cells reached a turbidity of 0.6, the culture was separated into two flasks of equal volume, to one of which toluene was added in the vapor phase. Protein production was inhibited with 30 μg/ml of tetracycline after an additional 30 min. Aliquots of 200 μl were removed at different time points after inhibition of protein production, to monitor TodS or TodT stability in the presence or absence of toluene. Ten-microliter samples were boiled for 5 min in Laemmli buffer, separated by SDS-PAGE, electroblotted to polyvinylidene difluoride (PVDF) membranes (Millipore, Madrid, Spain), and probed with polyclonal antibodies against TodS or TodT, generated in rabbits. The specific bands were detected by chemiluminescence [goat anti-rabbit IgG (H+L)-horseradish peroxidase conjugate; Caltag Labs, Burlingame, CA] and quantified with Quantity One software (Perkin Elmer).