Selection and Identification of a Newly Isolated Thermotolerant and Amylolytic Saccharomyces cerevisiae Strain for Ethanol Production

Thermotolerant and ethanogenic Saccharomyces cerevisiae ETGS1 was isolated from the grape samples by an enrichment technique using yeast extract peptone dextrose (YEPD) broth. This was obtained after the extensive screening of 67 samples from diverge ecosystem. The strain was found to tolerate ethanol concentration up to 12%. Enzyme profiling of this selected strain also revealed its amylolytic potentials. This isolate of S. cerevisiae was found to ferment YPS medium at elevated temperature in a single step with fermentation efficiency of 70.47%. It was found to produce 31 g/l of ethanol with yield of 0.4 (p/s, g/g). Looking to the prospects of this newly isolate for the conversion of starch based waste into ethanol in a single step without any complex pretreatments, it was selected for further thorough characterization. Based on the morphological, cultural and biochemical characterization followed by molecular analysis of 18S rDNA, it was identified as the strain of S. cerevisiae.