Graduate School of Sciences and Technology for Innovation, Tokushima University, 2-1 Minamijosanjima- cho, Tokushima, 770-8513, Japan.
Graduate School of Sciences and Technology for Innovation, Tokushima University, 2-1 Minamijosanjima- cho, Tokushima, 770-8513, Japan; Department of Bioscience and Bioindustry, Tokushima University, 2-1 Minamijosanjima- cho, Tokushima, 770-8513, Japan.
Chemosphere. 2024 Aug;362:142660. doi: 10.1016/j.chemosphere.2024.142660. Epub 2024 Jun 18.
This study proposed a two-stage pressurized microwave hydrothermal treatment with a catalyst, followed by enzymatic saccharification, as a pretreatment method for efficiently converting cellulose and hemicellulose from rice straw into glucose and xylose. The use of various inorganic salts and dilute sulfuric acid as catalysts enhances sugar production. Using 1 wt% sulfuric acid as a catalyst at 150 °C for 5 min for the first-stage and then 180 °C for 5 min for the second-stage yielded the highest sugar production from rice straw compared with other inorganic salts tested. The filtrate and enzymatic saccharification solution contained a total sugar of 0.434 g/g-untreated rice straw (i.e. 0.302 g-glucose/g-untreated rice straw and 0.132 g-xylose/g-untreated rice straw). When inorganic salts such as NaCl, MgCl, CaCl, and FeCl were used as catalysts, the highest sugar yield of 0.414 g/g-untreated rice straw (i.e. 0.310 g-glucose/g-untreated rice straw and 0.104 g-xylose/g-untreated rice straw) was obtained when using 1 wt% FeCl at 170 °C for 5 min in the first-stage and 190 °C for 5 min in the second-stage, with a value close to that of 1 wt% sulfuric acid. These findings suggest that two-stage treatment with a catalyst is a suitable pretreatment method for the production of glucose and xylose from rice straw owing to the different hydrolysis temperatures of cellulose and hemicellulose.
本研究提出了一种两步加压微波水热处理方法，使用催化剂，然后进行酶解糖化，作为一种有效的预处理方法，可将稻草中的纤维素和半纤维素高效转化为葡萄糖和木糖。使用各种无机盐和稀硫酸作为催化剂可提高糖的产量。与其他测试的无机盐相比，使用 1wt%硫酸作为催化剂，在第一阶段 150°C 下处理 5 分钟，然后在第二阶段 180°C 下处理 5 分钟，可从稻草中获得最高的糖产量。滤液和酶解糖化液中含有 0.434g/g-未处理稻草的总糖（即 0.302g-葡萄糖/g-未处理稻草和 0.132g-木糖/g-未处理稻草）。当使用 NaCl、MgCl、CaCl 和 FeCl 等无机盐作为催化剂时，在第一阶段使用 1wt%FeCl 在 170°C 下处理 5 分钟，在第二阶段在 190°C 下处理 5 分钟时，可获得 0.414g/g-未处理稻草的最高糖产量（即 0.310g-葡萄糖/g-未处理稻草和 0.104g-木糖/g-未处理稻草），与 1wt%硫酸的值相近。这些发现表明，对于从稻草中生产葡萄糖和木糖，两步处理加催化剂是一种合适的预处理方法，因为纤维素和半纤维素的水解温度不同。
