红外显微光谱在木质纤维细胞壁研究中的应用

木质纤维生物质资源的开发利用是当前国内外广泛关注的重大课题，为了提高木质纤维的利用效率、降低开发成本，人们亟需掌握木质细胞壁抗降解机理，深入了解细胞壁复杂的化学组成和分子结构。红外显微光谱作为一种可进行微区分析和无损检测的新技术，具有检测速度快、灵敏度高、制样简单等优点，已经被广泛运用在生物质原料及生物质预处理过程分子结构变化等的研究中。它能够快速准确地提供木质纤维细胞的化学组成和分子结构等信息，可用于植物细胞壁的区域化学研究。本文在简述红外显微光谱技术原理及具体实验方法的基础上，综述了红外显微光谱技术在探究木质纤维细胞壁化学组成及结构方面的应用进展，对细胞壁主要组分的原位分布、经预处理后组成的变化以及分子排列方向三个方面进行了总结。并对其在木质纤维细胞壁研究的应用前景进行了展望：提高显微镜的放大倍数、提高化学成像图的空间分辨率、与其他检测手段和仪器联合使用等。以期为木质纤维细胞壁的组分研究提供新手段。

Application of FTIR Microspectroscopy in the Study of Lignocellulosic Cell Walls

The development and utilization of lignocellulosic biomass resource becomes a major subject of widespread concern at home and abroad. To make better use of this resource and reduce cost, a thorough understanding of recalcitrance mechanism as well as chemical compositional and structural characteristics of lignocellulosic cell walls seems desiderated. With the property of fast testing, high sensitivity and simple sample preparation, FT-IR microspectroscopy can provide microanalysis and nondestructive test. It has been proved to accurately present compositional and structural information of lignocellulosic cell walls and be suitable for the study of topochemistry of main components at the cellular level. After a brief introduction of the principle of FT-IR microspectroscopy and its detailed experimental procedure, this review provides an overview on the feasibility of FTIR microspectroscopy in monitoring as well as evaluating the composition and structure of lignocellulosic cell walls from three aspects, including in situ distribution, changes after pretreatment and molecular orientation of the major components in cell walls. Some prospects, for example development of the magnification of the microscope and the spatial resolution of chemical imaging, combination with various analysis methods and instruments are also proposed. This technology can act as a new approach in characterizing lignocellulosic cell walls.