FIG 1.
Expression of phly-lacZ in response to FFA exposure. The promoter region of the PrfA-dependent hly gene cloned into vector pTCV-lac was transformed into EGDprfA*. The resulting strain was grown to an OD600 of 0.3 and exposed to SFFAs in a concentration of 10 μg/ml (50 μM LA, 44 μM MA, 39 μM PAL, or 35 μM SA) or 75 μg/ml (293 μM PAL+ or 264 μM SA+) (A) or to C18 FFAs in a concentration of 3 μg/ml (11 μM FFA) or 12 μg/ml (43 μM FFA+) (B). As controls, the cultures were left untreated (÷) or vehicle was added corresponding to the concentration present in the FFA-treated cultures (C or C+). Samples for the β-galactosidase assays were withdrawn after 20 h. Results are the average of three biological replicates, each carried out in technical duplicates.