Tamer I. M. Ragab1, Bahaa T. Shawky2, Hussein M. Hussein3*, Magdy K. Zahran3 1Chemistry of Natural and Microbial Products Department, Pharmaceutical and Drug Industries Research Division, National Research Centre, Dokki, Giza 12622, Egypt 2Microbial Chemistry Department, Genetic Engineering and Biotechnology Research Division, National Research Centre, Egypt 3Chemistry Department, Faculty of Science, Helwan University, Ain-Helwan, Cairo 11795, Egypt Abstract Rice straw (RS) and rice husk (RH) were selected as a local agricultural residues for biopolymers (cellulose, hemicellulose and lignin) extraction using 2% alkaline sodium hydroxide at 90oC for almost 3 hours. The extraction process was optimized by Taguchi experimental design method. Results revealed that cellulose was 54.6 % and 52.75 % in case of RS and RH, respectively. Separate hydrolysis and fermentation (SHF) were done using Aspergilus niger crude enzymes and Saccharomyces cerevisiae, which statistically optimized with two experimental design models (Taguchi and Placket-Burman design). Maximum glucose yield from hydrolysis of the extracted cellulose RS (CRS) and cellulose RH (CRH) was 255 mg/g and 120 mg/g, respectively. Bioethanol yield from the obtained fermentable glucose of CRS and CRH were 231.8 mg/g and 269.4 mg/g, respectively. Extraction, hydrolysis and fermentation processes optimization can be an alternative sustainable development approach to utilize this abundant agricultural waste for new and renewable energy. Keywords: Rice straw and husk, Response surface methodology, Taguchi and Placket-Burman design, Bioethanol | 
