Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China..
Int J Biol Macromol. 2019 Jul 15;133:514-521. doi: 10.1016/j.ijbiomac.2019.04.127. Epub 2019 Apr 17.
Eucalyptus wood was pretreated with an integrated process based on hydrothermal and alkaline pretreatments. The structural changes of hemicelluloses during the pretreatments and the components of the hydrolysates were comprehensively characterized. Sugar and spectral analyses indicated that the hemicelluloses remained in the residues obtained at hydrothermal pretreatment under low temperatures were mainly composed of a (1 → 4)-β-D-Xylp backbone with 4-O-methyl-α-D-glucuronic acids attached at O-2 of the xylose together with various monosaccharides of rhamnose, arabinose, galactose, glucose, and mannose. The pretreatments resulted in serious degradation of hemicelluloses at high pretreatment temperatures. The distribution changes of the hemicelluloses in the cell walls during the integrated pretreatments were detected by Confocal Raman Microscopy, which revealed that the dissolution of hemicelluloses in different morphological regions was inhomogeneous, and the a large portion of hemicelluloses were removed from the secondary cell wall regions during the pretreatments.
桉木经过基于水热和堿预处理的综合处理进行预处理。全面表征了预处理过程中半纤维素的结构变化和水解产物的成分。糖和光谱分析表明，在低温下水热处理后残留在残留物中的半纤维素主要由（1→4）-β-D-木吡喃糖主链组成，其中 4-O-甲基-α-D-葡萄糖醛酸连接在木糖的 O-2 上，同时还含有鼠李糖、阿拉伯糖、半乳糖、葡萄糖和甘露糖等各种单糖。在高预处理温度下，预处理会导致半纤维素严重降解。通过共焦拉曼显微镜检测到细胞壁中半纤维素在综合预处理过程中的分布变化，表明不同形态区域的半纤维素溶解不均匀，大部分半纤维素在预处理过程中从次生细胞壁区域中去除。
