Alkane susceptibility assay for S. cerevisiae . Alkane susceptibility assays were performed in S. cerevisiae cells expressing ABC2, ABC3 or with an empty plasmid. (A) Alkane susceptibility assay on agar plates. Serial 10-fold dilutions (from left to right: non diluted, 10-1, 10-2, 10-3) of cells were spotted on agar plates with alkanes (octane, nonane, decane, undecane and dodecane) as vapor phase. Plates were incubated at 28°C for 2 days. (B) Alkane susceptibility assay in liquid culture. Overnight cell culture was diluted into induction medium (final OD600=0.4) with alkanes (decane or undecane). The cell culture was incubated for 48 h at 28°C. The OD600 value of each sample was determined and plotted against its corresponding alkane concentration (0.1%, 0.25%, 0.5%, 0.75%, 1%, 2%, 5%, 10% and 20% vol/vol). Each point represents the mean of three biological replicates; standard deviations are presented. Arrows indicate increased cell tolerance towards alkanes. (C) Growth file of cells in alkane-inhibiting conditions (0.5% (vol/vol) decane or 20% (vol/vol) undecane). Symbols for strains are: control sample with empty plasmid (open circle), cells expressing ABC2 (filled circle), cell expressing ABC3 (filled triangle).