Department of Chemical and Biological Engineering, Korea University, Seoul, 136-701, South Korea.
Department of Chemical Engineering, Kyonggi University, Suwon 443-760, South Korea.
Biotechnol Biofuels. 2013 Jul 30;6:109. doi: 10.1186/1754-6834-6-109. eCollection 2013.
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.
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°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.
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 α-cellulose.
由于木质纤维素生物质可以通过生物过程转化为各种多功能的化学化合物，因此最近受到了关注。在这项研究中，通过两步预处理（稀硫酸和氨水），有效地将稻草转化为可发酵糖。通过统计方法对氨水浸泡过程进行了优化。
采用响应面法。发现决定系数（R(2)）值为 0.9607，变异系数为 6.77。最佳预处理条件为温度 42.75°C、氨水浓度 20.93%和反应时间 48 h。糖化的最佳酶浓度为 30 滤纸单位。结晶度指数约为 60.23%，傅里叶变换红外结果显示出明显的葡聚糖峰。使用酿酒酵母 K35 进行乙醇生产，以验证从稻草中糖化得到的葡萄糖是否可发酵。
稀硫酸和氨水联合预处理稻草可有效产生可发酵糖，其结晶度指数几乎与α-纤维素相同。
