Repeated-batch fermentation of sugarcane bagasse hemicellulosic hydrolysate to ethanol using two xylose-fermenting yeasts

摘要: In this study, a repeated-batch fermentation of hemicellulosic sugarcane bagasse hydrolysate was investigated to produce bioethanol using two xylose-fermenting yeasts, Scheffersomyces stipitis and Scheffersomyces shehatae. First, diluted-acid pretreatment of sugarcane bagasse at 150 mg H2SO4/g dry bagasse and 127 °C for 10 min, followed by concentration (3.5-fold), and detoxification process led to a hemicellulosic hydrolysate containing 48.97 g L−1 xylose. The hemicellulosic hydrolysate was fermented using repeated-batch operation and studying the performance of S. stipitis and S. shehatae yeasts. The results showed that fermentative parameters through the repeated-batch were significantly increased, and the ability of yeasts was maintained during the two cycles (a total of third rounds). Furthermore, S. shehatae was 85% more efficient in xylose to ethanol conversion than S. stipitis, producing 21.5 g L …