effect of selenium and molasses on the growth of Saccharomyces cerevisiae and yield of bioethanol production

Bioethanol is used as substitute fuel to reduce dependency on fossil fuels, ensure energy security and reduce the negative impact of fossil fuel consumption to the economy and the environment sugar beet Malass are very good raw materials for ethanol production due to their content of fermentable sugars, which can be directly used for fermentation without any modification. Previous studies have shown that Selenium enriched yeast (Se-yeast) is a good carrier for selenium biotransformation. Therefore one of the most economical sources of organic selenium is yeast grown in a selenium-enriched culture medium. The main objectives of the present study were to evaluate the effect of selenium on the yield of bioethanol production and achieve the bioethanol with highest concentration, and compare the concentration of produced bioethanol, using S. cerevisiae, at obtained optimum condition with and without using selenium. For preparation of the growth media molasses was sterilized. After addition of the 0.3 g of the S. cerevisiae strain, SFO6 for the nutrition in molasses as fermentation media was enriched by addition of 500 and 250 ppm of (NH4)2HPO4 and urea, respectively and different amount of selenium (0, 5, 10, 15, 20 and 25 μg).The effect of different amounts of selenium and molasses on bioethanol yield was investigated. Obtained results revealed that maximum bioethanol concentration (80g/L) was achieved using 20μg selenium and molasses with 25°Bx. S. cerevisiae is a good option for increasing bioethanol production efficiency from selenium-enriched sugar beet molasses