The effects of activation time on the production of fructose and bioethanol from date extract
In this study, fructose and bioethanol were produced from date's extract by fermentation using Saccharomyces cerevisiae, mutant strain ATCC 36858 and wild strain STAR brand, where the latter was activated at different periods: 30 min, 1, 2 and 3 days. Profiles of sugar consumption and bioethanol production using STAR were found to be almost having the same pattern for all activation periods, while fructose was consumed as well as glucose. Enhancement of fructose in sugar can only be obtained at the expense of ethanol. In order to obtain 75 and 90% fructose in sugar, the respective losses in fructose exceeded 39 and 63%. On the other hand, the results demonstrate that S. cerevisiae ATCC 36858 could selectively convert glucose to ethanol and biomass with minimal fructose conversion. A high fructose yield above 91% of the original fructose was obtained with ATCC 36858. In addition, the ethanol yield was found to be 63% of the theoretical.
Keywords: Saccharomyces cerevisiae, fructose, glucose, bioethanol, fermentation