显微技术在木质纤维素生物质预处理 研究中的应用进展

木质纤维素生物质细胞壁中主要组分(纤维素、半纤维素和木质素)相互交织形成的网状结构是生物质转化过程中的天然抗降解屏障。有效的预处理能打破这种屏障,提高酶水解转化效率。显微技术包括显微镜技术和显微光谱技术,能够在多尺度下展现木质纤维素生物质在预处理中细胞壁微观结构变化和组分含量等信息。笔者介绍了原子力显微镜、扫描电子显微镜、透射电子显微镜、显微拉曼光谱等显微技术在木质纤维素生物质预处理过程研究中的应用。利用显微镜技术可直接观察预处理中细胞壁表面结构的变化,并分析其对酶水解可能产生的影响; 利用显微光谱技术可原位分析预处理对细胞壁组分化学结构与超微结构的影响; 多种显微技术组合弥补了单一手段的不足,可获得木质纤维原料生物构造、组分含量及分布等方面更为详细的信息。
The network structure which is formed by the components(cellulose, hemicellulose and lignin)of lignocellulosic biomass cell wall is believed to be the natural recalcitrance in the process of biomass conversion. A proper pretreatment is an efficient pathway to break this recalcitrance and enhance the conversion yield of enzymatic hydrolysis. Microscopic techniques including microscopy and microspectroscopy can be used to observe the microstructure of cell wall and analyze the change of component characteristics at multi-scales. The application of microscopic techniques, such as AFM, SEM, TEM and Raman microscopy on the process study of lignocellulosic biomass pretreatment, was briefly introduced in this review. The morphological change of cell wall surface and its effect on the enzymatic hydrolysis can be observed by microscopy technique. Microspectroscopy technique can be applied on in-situ analysis of component and ultrastructure changes of the cell wall during the pretreatment. The combination of multi-microscopic techniques covers the shortage of mono-technique, which can obtain the detail information on the biomass structure, as well as the content and distribution of cell wall components