Pretreatment and hydrolysis of cellulosic agricultural wastes with a cellulase-producing Streptomyces for bioethanol production

• Published in: Biomass & bioenergy 2011-05, Vol.35 (5), p.1878-1884
• Main Authors: Hsu, Chuan-Liang, Chang, Ku-Shang, Lai, Ming-Zhang, Chang, Tsan-Chang, Chang, Yi-Huang, Jang, Hung-Der
• Format: Article
• Language: English
• Subjects: agricultural wastes; Alcohols: methanol, ethanol, etc; Alternative fuels. Production and utilization; Applied sciences; beta-glucosidase; Bioethanol; Biomass; cellulose; Cellulosic hydrolysates; corn cobs; Corncob; Energy; Ethanol; ethanol fermentation; ethanol production; Ethyl alcohol; Exact sciences and technology; Fermentation; fuel production; Fuels; Glucose; Hydrolysates; Hydrolysis; Reducing sugar; Saccharomyces cerevisiae; Streptomyces; Streptomyces sp; Sugars
• ISSN: 0961-9534; 1873-2909
• DOI: 10.1016/j.biombioe.2011.01.031

Production of reducing sugar by hydrolysis of corncob material with Streptomyces sp. cellulase and ethanol fermentation of cellulosic hydrolysate was investigated. Cultures of Streptomyces sp. T3-1 improved reducing sugar yields with the production of CMCase, Avicelase and β-glucosidase activity of 3.8, 3.9 and 3.8 IU/ml, respectively. CMCase, Avicelase, and β-glucosidase produced by the Streptomyces sp. T3-1 favored the conversion of cellulose to glucose. It was recognized that the synergistic interaction of endoglucanase, exoglucanase and β-glucosidase resulted in efficient hydrolysis of cellulosic substrate. After 5 d of incubation, the overall reducing sugar yield reached 53.1 g/100 g dried substrate. Further fermentation of cellulosic hydrolysate containing 40.5 g/l glucose was performed using Saccharomyces cerevisiae BCRC 21812, 14.6 g/l biomass and 24.6 g/l ethanol was obtained within 3 d. The results have significant implications and future applications regarding to production of fuel ethanol from agricultural cellulosic waste. ► Hydrolysis efficiency of cellulosic material was improved by Streptomyces sp. T3-1. ► The synergistic interaction of cellulases resulted in efficient hydrolysis of substrate. ► A significantly higher ethanol yield (0.67 g ethanol/g glucose) was achieved.