Sun Yong, Zhuang Junping, Lin Lu, Ouyang Pingkai
State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640, Guangdong Province, China.
Biotechnol Adv. 2009 Sep-Oct;27(5):625-32. doi: 10.1016/j.biotechadv.2009.04.023. Epub 2009 May 3.
We studied the process of conversion of microcrystalline-cellulose into fermentable glucose in the formic acid reaction system using cross polarization/magic angle spinning (13)C-nuclear magnetic resonance, X-ray diffraction and Fourier transform infrared spectroscopy. The results indicated that formic acid as an active agent was able to effectively penetrate into the interior space of the cellulose molecules, thus collapsing the rigid crystalline structure and allowing hydrolysis to occur easily in the amorphous zone as well as in the crystalline zone. The microcrystalline-cellulose was hydrolyzed using formic acid and 4% hydrochloric acid under mild conditions. The effects of hydrochloric acid concentration, the ratio of solid to liquid, temperature (55-75 degrees C) and retention time (0-9 h), and the concentration of glucose were analyzed. The hydrolysis velocities of microcrystalline-cellulose were 6.14 x 10(-3) h(-1) at 55 degrees C, 2.94 x 10(-2) h(-1) at 65 degrees C, and 6.84x10(-2) h(-1) at 75 degrees C. The degradation velocities of glucose were 0.01 h(-1) at 55 degrees C, 0.14 h(-1) at 65 degrees C, 0.34 h(-1) at 75 degrees C. The activation energy of microcrystalline-cellulose hydrolysis was 105.61 kJ/mol, and the activation energy of glucose degradation was 131.37 kJ/mol.
我们使用交叉极化/魔角旋转（13）C-核磁共振、X射线衍射和傅里叶变换红外光谱研究了微晶纤维素在甲酸反应体系中转化为可发酵葡萄糖的过程。结果表明，甲酸作为活性剂能够有效地渗透到纤维素分子的内部空间，从而破坏刚性晶体结构，使水解易于在无定形区以及结晶区发生。在温和条件下，用甲酸和4%盐酸对微晶纤维素进行水解。分析了盐酸浓度、固液比、温度（55-75℃）和保留时间（0-9小时）以及葡萄糖浓度的影响。微晶纤维素在55℃时的水解速度为6.14×10（-3）h（-1），在65℃时为2.94×10（-2）h（-1），在75℃时为6.84×10（-2）h（-1）。葡萄糖在55℃时的降解速度为0.01 h（-1），在65℃时为0.14 h（-1），在75℃时为0.34 h（-1）。微晶纤维素水解的活化能为105.61 kJ/mol，葡萄糖降解的活化能为131.37 kJ/mol。
