Bio-Ethanol Production from Wheat Straw Using Yeast Isolates

Abstract

In the first hand, the cost of fossil fuel is increasing alarmingly. On the second hand, combustion of fossil fuels contributes for global warming. Therefore, it need to strength the production of renewable energies. The aim of this study was to produce bioethanol from wheat straw using yeast isolates. The isolates were isolated from decomposed soil, termite soil and rotten wood samples using yeast extract peptone dextrose media (YPD) and characterized chemically and morphologically. The wheat straws were powdered and hydrolyzed with dilute sulfuric acids. After neutralization, it was used to produce ethanol. Response surface methodology was employed to optimize the ethanol production process from wheat straws. The isolates were grown optimally at a temperature of 30^oC, pH nearly 5, and sugar concentration 70 to 120 g/L.  Among hydrolysis conditions, lower acid concentration (less than 1.5%) and temperature of 60^oC resulted higher reducing sugars. The optimization study showed that the highest bio-ethanol concentration of 6.8g/l was observed by SWX under the optimum conditions of with 1% H2S04, 60oC temperature and 52.5-minute time hydrolysis at 30°C for 48 hour incubation time. Wheat straws could be good candidate for ethanol production.