Ling Zhe, Guo Zongwei, Huang Caoxing, Yao Lei, Xu Feng
Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China; Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
Bioresour Technol. 2020 Jun;305:123025. doi: 10.1016/j.biortech.2020.123025. Epub 2020 Feb 14.
Discovering green solvents and their inner mechanisms for efficient deconstruction of lignocellulosic biomass recalcitrance are receiving growing interests. In this work, eco-friendly levulinic acid (LA) based deep eutectic solvents (DES) were proposed for pretreatment on moso bamboo by combining acetamide (Am), betaine (Ba) and choline chloride (ChCl) as hydrogen bonding acceptors. LA/ChCl pretreated materials showed optimal enzymatic accessibility with the highest glucose yield (79.07%) because of its higher lignin removal, morphological disruption and decreased crystallinity. Moreover, the microvoids (averagely 30 nm) and cracks were observed for cellulose microfibrils in anisotropic directions, which resulted in shorter microfibrils and crystallites facilitating the enzymatic hydrolysis. The studies on recyclability revealed that LA/Ba DES had better recycling performance due to its maintaining capability of lignin extraction. Series of supramolecular changes on oriented crystalline cellulose were determined in this work by novel LA based DES, which may provide new alternatives for biomass pretreatments.
发现绿色溶剂及其有效解构木质纤维素生物质顽固特性的内在机制正受到越来越多的关注。在这项工作中，提出了以生态友好型乙酰丙酸（LA）为基础的深共熔溶剂（DES），通过将乙酰胺（Am）、甜菜碱（Ba）和氯化胆碱（ChCl）作为氢键受体来对毛竹进行预处理。LA/ChCl预处理的材料表现出最佳的酶可及性，葡萄糖产率最高（79.07%），这是因为其木质素去除率更高、形态破坏以及结晶度降低。此外，在纤维素微纤丝的各向异性方向观察到微孔隙（平均30纳米）和裂缝，这导致微纤丝和微晶变短，有利于酶解。可回收性研究表明，LA/Ba DES由于其保持木质素提取的能力而具有更好的回收性能。这项工作通过新型的基于LA的DES确定了取向结晶纤维素上一系列的超分子变化，这可能为生物质预处理提供新的选择。
