Kim, Sung Bong Lee, Sang Jun Lee, Ju Hun Jung, You Ree Thapa, Laxmi Prasad Kim, Jun Seok Um, Youngsoon Park, Chulhwan Kim, Seung Wook 2024-01-20T12:02:52Z 2024-01-20T12:02:52Z 2021-09-05 2013-07 1754-6834 https://pubs.kist.re.kr/handle/201004/127916 Background: Use of lignocellulosic biomass has received attention lately because it can be converted into various versatile chemical compounds by biological processes. In this study, a two-step pretreatment with dilute sulfuric acid and aqueous ammonia was performed efficiently on rice straw to obtain fermentable sugar. The soaking in aqueous ammonia process was also optimized by a statistical method. Results: Response surface methodology was employed. The determination coefficient (R-2) value was found to be 0.9607 and the coefficient of variance was 6.77. The optimal pretreatment conditions were a temperature of 42.75 degrees C, an aqueous ammonia concentration of 20.93%, and a reaction time of 48 h. The optimal enzyme concentration for saccharification was 30 filter paper units. The crystallinity index was approximately 60.23% and the Fourier transform infrared results showed the distinct peaks of glucan. Ethanol production using Saccharomyces cerevisiae K35 was performed to verify whether the glucose saccharified from rice straw was fermentable. Conclusions: The combined pretreatment using dilute sulfuric acid and aqueous ammonia on rice straw efficiently yielded fermentable sugar and achieved almost the same crystallinity index as that of alpha-cellulose. English BioMed Central Pretreatment of rice straw with combined process using dilute sulfuric acid and aqueous ammonia Article 10.1186/1754-6834-6-109 1 Biotechnology for Biofuels, v.6 Biotechnology for Biofuels 6 Y scie scopus 000322727900001 2-s2.0-84880916047 Biotechnology & Applied Microbiology Energy & Fuels Biotechnology & Applied Microbiology Energy & Fuels Article SURFACE METHODOLOGY RSM LIGNOCELLULOSIC BIOMASS BIOETHANOL PRODUCTION ENZYMATIC-HYDROLYSIS STRUCTURAL FEATURES CORN STOVER OPTIMIZATION SACCHARIFICATION DIGESTIBILITY SOAKING Rice straw Pretreatment Soaking aqueous ammonia Dilute acid pretreatment Response surface methodology