Background: Yeast strains are exposed to numerous environmental stresses during industrial alcoholic fermentation. High temperature accumulated acetic acid, enhanced the growth inhibition and decreased ethanol production.

Results: In this study the influence of high temperature on the cellular and mitochondrial membrane integrity of Saccharomyces cerevisiae as well as reactive oxygen species (ROS) formation were investigated to the understand the mechanisms of the high temperature fermentation process. However, increasing the temperature to 42ºC resulted in a clear decrease in the cytoplasmic and mitochondrial membrane potential and an increase in intracellular ROS formation. It was also determined that the different thermostability between YZ1 and YF31 strains had a clear correlation with the yeast's intracellular trehalose content of the cell. Finally, random amplified polymorphic DNA (RAPD) was used to explore the genome differences between the YZ1 and YF31 strains.