Research Institute for Catalysis, Chonnam National University, Gwangju, 500-757, Korea.
Bioprocess Biosyst Eng. 2012 Jan;35(1-2):43-8. doi: 10.1007/s00449-011-0589-9. Epub 2011 Sep 10.
Rice straw is a lignocellulosic biomass that constitutes a renewable organic substance and alternative source of energy; however, its structure confounds the liberation of monosaccharides. Pretreating rice straw using a TiO(2)/UV system facilitated its hydrolysis with Accellerase 1000(™), suggesting that hydroxyl radicals (OH·) from the TiO(2)/UV system could degrade lignin and carbohydrates. TiO(2)/UV pretreatment was an essential step for conversion of hemicellulose to xylose; optimal conditions for this conversion were a TiO(2) concentration of 0.1% (w/v) and an irradiation time of 2 h with a UV-C lamp at 254 nm. After enzymatic hydrolysis, the sugar yields from rice straw pretreated with these parameters were 59.8 ± 0.7% of the theoretical for glucose (339 ± 13 mg/g rice straw) and 50.3 ± 2.8% for xylose (64 ± 3 mg/g rice straw). The fermentation of enzymatic hydrolysates containing 10.5 g glucose/L and 3.2 g xylose/L with Pichia stipitis produced 3.9 g ethanol/L with a corresponding yield of 0.39 g/g rice straw. The maximum possible ethanol conversion rate is 76.47%. TiO(2)/UV pretreatment can be performed at room temperature and atmospheric pressure and demonstrates potential in large-scale production of fermentable sugars.
稻草是一种木质纤维素生物质，构成可再生有机物质和能源的替代物；然而，其结构阻碍了单糖的释放。使用 TiO(2)/UV 系统预处理稻草，有助于使用 Accellerase 1000(™)进行水解，表明 TiO(2)/UV 系统中的羟基自由基 (OH·) 可以降解木质素和碳水化合物。TiO(2)/UV 预处理是将半纤维素转化为木糖的重要步骤；这种转化的最佳条件是 TiO(2)浓度为 0.1%（w/v），在 254nm 的 UV-C 灯下辐照 2 小时。经过酶解后，用这些参数预处理的稻草的糖收率为理论值的 59.8±0.7%（葡萄糖 339±13mg/g 稻草）和 50.3±2.8%（木糖 64±3mg/g 稻草）。用 Pichia stipitis 发酵含 10.5g 葡萄糖/L 和 3.2g 木糖/L 的酶解液，可产生 3.9g 乙醇/L，相应的稻草产率为 0.39g/g。最大可能的乙醇转化率为 76.47%。TiO(2)/UV 预处理可以在室温常压下进行，具有大规模生产可发酵糖的潜力。
