Liu Wei, Zhuo Shengnan, Si Mengying, Yuan Mengting, Shi Yan
School of Life Science, Tonghua Normal University, Tonghua, 134000, China.
School of Metallurgy and Environment, Central South University, Changsha, 410083, China.
BMC Chem. 2020 Dec 10;14(1):72. doi: 10.1186/s13065-020-00725-y.
Lignocellulosic biomass is considered as the largest potential candidate to develop alternative energy, such as biofuel, biomaterial. However, the efficient conversion of cellulose and practical utilization of lignin are great challenges for sustainable biorefinery. In this study, high reducing sugar yield and different size of lignin colloid particles (LCPs) were obtained via tetrahydrofuran-water (THF-HO) pretreatment of corn stover (CS). THF-HO as a co-solvent, could efficiently dissolve lignin and retain cellulose. After the pretreatment, 640.87 mg/g of reducing sugar was produced, that was 6.66-fold higher than that of the untreated CS. Meanwhile, the pretreatment liquor could form spherical LCPs with different sizes ranged from 202 to 732 nm through self-assembly. We studied the optimal pretreatment condition to simultaneously realize the high reducing sugar yield (588.4 mg/g) and excellent LCPs preparation with average size of 243 nm was under TH22 (THF-HO pretreatment at 120 °C for 2 h). To further explore the formation of LCPs with different sizes. We studied the lignin structure changes of various conditions, concluded the size of LCPs was related to the lignin concentration and syringyl/guaiacyl (S/G) ratio. As the increase of the lignin concentration and S/G, the sizes of LCPs were increased. G-type lignin was easier to dissolve in the mild pretreatment supernatant, contributing to form smaller LCPs with a good dispersibility. In the severe condition, both of S and G-type lignin were dissolved due to the lignin depolymerization, formed the larger sphere particles. This work provides a novel perspective for the technical design of lignocellulosic biomass conversion.
木质纤维素生物质被认为是开发替代能源（如生物燃料、生物材料）的最大潜在候选物。然而，纤维素的高效转化和木质素的实际利用是可持续生物炼制面临的巨大挑战。在本研究中，通过玉米秸秆（CS）的四氢呋喃 - 水（THF - H₂O）预处理获得了高还原糖产量和不同尺寸的木质素胶体颗粒（LCPs）。THF - H₂O作为共溶剂，能够有效溶解木质素并保留纤维素。预处理后，产生了640.87 mg/g的还原糖，比未处理的CS高6.66倍。同时，预处理液通过自组装可形成尺寸范围为202至732 nm的不同大小的球形LCPs。我们研究了最佳预处理条件，以同时实现高还原糖产量（588.4 mg/g）和制备平均尺寸为243 nm的优异LCPs，该条件为TH22（在120℃下进行2小时的THF - H₂O预处理）。为了进一步探索不同尺寸LCPs的形成。我们研究了各种条件下木质素结构的变化，得出LCPs的尺寸与木质素浓度和紫丁香基/愈创木基（S/G）比有关。随着木质素浓度和S/G的增加，LCPs的尺寸增大。G型木质素更容易溶解在温和预处理的上清液中，有助于形成具有良好分散性的较小LCPs。在苛刻条件下，由于木质素解聚，S型和G型木质素都被溶解，形成较大的球形颗粒。这项工作为木质纤维素生物质转化的技术设计提供了新的视角。
