Among the stress conditions tested, the only difference between the ethanol-exposed and control L. plantarum cultures was the increased capacity of the ethanol-exposed cells to survive at elevated temperatures. Although all cultures exhibited an exponential decay in viability in the presence of heat, L. plantarum cells grown until exponential phase in MRS containing 8% ethanol for 24 h (OD600 = 1.0) survived longer and at higher temperatures between 37°C and 53°C over a range of 0- to 60-min exposure times than did cells harvested at the same optical density in normal MRS. This was observed by plotting the log10 values of temperature and time when 1% of the starting population was still able to form a colony after heat exposure (Fig. 5).