Comparative Study of Three Commercial Strains of Saccharomyces for Enhanced Production of Biofuel Using High Gravity Molasses
By: Muzna Hashmi, Aftab Iqbal Shafi, Fariha Hasan, Abdul Hameed, Aamer Ali Shah
Key Words: Biofuel, Saccharomyces cerevisiae, High gravity molasses.
Int. J. Biosci. 8(2), 106-114, February 2016.
The potential of different commercial strains of Saccharomyces cerevisiae was studied for enhanced production of bioethanol under high gravity condition. Three strains i.e. Rossmoor, Saf-instant and Uvaferm-43, were compared in order to select best commercial yeast that could be utilized on industrial scale for production of bio-ethanol. Osmotic pressure is one of the main stress factors faced by microbial strains during fermentation process where high gravity sugarcane molasses is used as a substrate. Under optimized physicochemical parameters, osmotic (sugar) tolerance of all strains, i.e. Rossmoor, Saf-instant and Uvaferm-43, to high gravity molasses was determined, which came out as 15, 17 and 25% (w/v), respectively. Maximum ethanol yield by these strains was 6.5%, 7.5% and 9.3 % (v/v) with fermentation efficiency of 72.6%, 69.2% and 58.1% respectively. It is concluded from the present study that Uvaferm-43 is the best strain for industrial use which has the ability to produce maximum ethanol under stressful condition but more research should be done to enhance its fermentation efficiency.