Effects of ethanol on thermal death and on the maximum temperature for growth of the yeast Kluiveromyces fragilis

The maximum temperature for growth of a strain of Kluyveromyces fragiliswas depressed by increasing ethanol concentration from its normal value around 45 °C to 26.5 °C at 6.4% (w/v) of ethanol. Ethanol enhanced thermal death by increasing ΔS≠, the entropy of activation of thermal death. Entropy coefficients of 7.6 entropy units per mol of ethanol per liter of medium for unadapted cells and of 5.7 for adapted cells ware obtained.