Effect of constituents molar ratios of deep eutectic solvents on rice straw fractionation efficiency and the micro-mechanism investigation
Effect of constituents molar ratios of deep eutectic solvents on rice straw fractionation efficiency and the micro-mechanism investigation
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DOI：
10.1016/j.indcrop.2018.04.076
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发表时间：
2018-09-15
影响因子：
5.9
通讯作者：
Fu, Ming-Hui
中科院分区：
文献类型：
--
作者：
Hou, Xue-Dan;Lin, Kai-Peng;Fu, Ming-Hui
研究了氯化胆碱-草酸二水合物（CO）对水稻秸秆中可发酵糖等平台化学物质的有效提取及其微观机制。选择合适的组分摩尔比的CO似乎是一个可行的方法，以实现一个良好的生物质分馏适当的预处理程度。采用高二水合草酸与氯化胆碱摩尔比的CO进行预处理，可以获得易消化的富含纤维素的材料（cmr, bbb80 %）和高纯度的富含木质素的材料（LRMs）（> 82%），因为它可以广泛地去除半纤维素（> 93%）和脱木质素（约70%）。基于共聚焦激光扫描显微镜（CLSM）和透射电镜（TEM）的细胞壁微观结构表征证实，草酸二水合物含量越高，CO对木聚糖和木质素的去除能力越强。此外，CLSM证实木聚糖的大量去除有利于脱木质素和随后的纤维素酶解。此外，透射电镜观察木质素在细胞壁分布的超微结构变化表明木质素发生了部分脱木质素作用，主要发生在细胞角（CC）和复合中腔（CML），而不是在次生细胞壁。这些发现为酸性DESs介导的生物质解构的详细机制提供了新的见解。
Effective obtaining fermentable sugars and other platform chemicals from rice straw mediated by choline chloride- oxalic acid dihydrate (CO) and the corresponding micro-mechanism investigation were conducted in this work. Choosing a suitable constituents molar ratio of CO appeared to be a feasible method to achieve an appropriate pretreatment severity for a good biomass fractionation. Pretreatment by using CO with high oxalic acid dihydrate to choline chloride molar ratio could afford easily digestible cellulose-rich materials (CMRs, > 80% of enzymatic digestion) and lignin-rich materials (LRMs) of high purity (> 82%) due to extensive hemicellulose removal (> 93%) and delignification (around 70%). Cell wall microstructure characterizations based on confocal laser scanning microscopy (CLSM) and transmission electron microscopy (TEM) verified the stronger xylan and lignin removal ability of CO with higher oxalic acid dihydrate content. Moreover, the considerable removal of xylan confirmed by CLSM was beneficial to delignification and the subsequent cellulose enzymatic hydrolysis. Furthermore, ultra-structural changes of lignin distribution in cell walls based on TEM indicated the occurrence of partial delignification, preferentially in cell corner (CC) and compound middle lumen (CML) rather than in the secondary cell walls. These findings provides a new insight into the detailed mechanism of acidic DESs mediated biomass deconstruction.