Comparative study of bioethanol production from acid and enzymatically hydrolyzed cotton stalk using co culture of Saccharomyces cerevisiae and Pachysolen tannophilus

Cotton stalk is one of the abundant feedstock and has been selected for producing ethanol at economically feasible manner. In the present investigation a comparative account of ethanol production has been developed from acid and enzymatically hydrolyzed cotton stalks. For this cotton stalk was subjected to series of treatment including acid hydrolysis followed by detoxifi cation in one set; and alkaline pretreatment followed by enzyme hydrolysis in second set. The sugars released during acid and enzyme hydrolysis was obtained as 11g/L and 24.5 g/L respectively. Both the sets were separately fermented for ethanol production. During fermentation, test organisms in association utilized 93.84% and 97.81% of total available sugars and produced an ethanol concentration of 4.96 g/L and 9.56 g/L with corresponding yield of 0.179 g/g and 0.191 g/g of biomass (native cotton stalk) respectively.