eng Science and Education Publishing American Journal of Microbiological Research 2013-04-23 1 1 39 44 10.12691/ajmr-1-3-1 AJMR2013131 article Sachin Kumar sachin.biotech@gmail.com 1 2 3 Pratibha Dheeran 3 4 Surendra P. Singh 5 Indra M. Mishra 5 Dilip K. Adhikari 5 Sardar Swaran Singh National Institute of Renewable Energy, Kapurthala, India Department of Paper Technology, Indian Institute of Technology, Roorkee, Saharanpur Campus, India The growth of thermotolerant/ thermophilic ethanol producing yeast and the fermentation processes using sugary substrates are exothermic processes. If the fermenters are heat insulated, the requirement of heat for maintaining the fermentation broth for ethanol production may be reduced considerably. The heat generated due to growth of thermotolerant yeast Kluyveromyces sp. IIPE453 was found to be 652kJ mol^-1 at 50ˇăC using glucose as a substrate. The heat generated due to ethanol formation by Kluyveromyces sp. IIPE453 was found to be 132.54kJ mol^-1 of sugar consumed or 67.84kJ mol^-1 of ethanol produced at 50ˇăC using sugarcane molasses as substrate. This heat would be sufficient for maintaining the desired temperature, if insulated fermentation systems are used. Therefore, no additional heat would be required to maintain the temperature in fermentation process by thermotolerant yeast at 50ˇăC. http://pubs.sciepub.com/ajmr/1/3/1/ajmr-1-3-1.pdf metabolic heat bioreactor ethanol fermentation thermotolerant yeast cooling water