However, a decreasing trend in ethanol concentration appeared at 37 C. When the fermentation temperature was further increased to 39 C, ethanol concentration and yeast cell viability decreased to approximately 40 g L1 and 53%, respectively. As shown in Fig. 5, temperature negatively influenced cell activity, and lack of activity at 37 C led to decrease in ethanol concentration. The cell activity at 39 C was slight higher than that at 37 C due to lower ethanol concentration that alleviated the inhibition effect on yeast cells. Performing the continuous ethanol fermentation at 35 C, an