The Application of Thermotolerant Yeast Kluyveromyces marxianus as a Potential Industrial Workhorse for Biofuel Production

Abstract

Kluyveromyces marxianus is a well-known thermotolerant yeast. Although Saccharomyces cerevisiae is the most commonly used yeast species for ethanol production, the thermotolerant K. marxianus is more suitable for simultaneous saccharification and fermentation (SSF) processes. This is because enzymatic saccharification usually requires a higher temperature than that needed for the optimum growth of S. cerevisiae. In this study, we compared the fermentation patterns of S. cerevisiae and K. marxianus under various temperatures of fermentation. The results show that at a fermentation temperature of 45°C, K. marxianus exhibited more than two fold higher growth rate and ethanol production rate in comparison to S. cerevisiae. For SSF using starch or corn stover as the sole carbon source by K. marxianus, the high temperature (45°C) fermentations showed higher enzymatic activities and ethanol production compared to SSF at 30°C. These results demonstrate the potential of the thermotolerant yeast K. marxianus for SSF in the industrial production of biofuels.