Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming 650500, China.
Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650500, China.
Int J Biol Macromol. 2024 Nov;279(Pt 4):135512. doi: 10.1016/j.ijbiomac.2024.135512. Epub 2024 Sep 10.
Tobacco stalks, as one of the annual economic crops rich in biomacromolecules such as cellulose and hemicellulose, are more difficult to decompose into cellulose fibers due to their high degree of lignification compared to other ordinary straw feedstocks, resulting in their underutilization. In this study, we developed a mild three-stage alkali‑oxygen (AO) process to efficiently deconstruct the tobacco stalk cell walls. The process, involving alkaline dosages of 15 %, 10 %, and 3 % at each stage, effectively dissociated the cell walls and yielded cellulose fibers with high brightness (42.0 % ISO). The organics in the spent liquor, including lignin, hemicellulose, and small-molecular extracts, were isolated through acid/ethanol precipitation and organic solvent extraction. Lignin characterization by 2D HSQC NMR indicated that the majority of native β-aryl ether linkages were preserved after AO treatment, making it suitable for producing chemicals or biofuels via depolymerization. Additionally, the small-molecular extracts contained numerous depolymerized products from lignin and carbohydrates, as well as bioactive compounds derived from the tobacco stalk. Overall, this mild, efficient, and eco-friendly process offers a promising approach for the valorization of tobacco stalks and similar biomass resources.
烟草秸秆作为一种富含纤维素和半纤维素等生物大分子的一年生经济作物，由于其木质化程度较高，比其他普通秸秆原料更难分解为纤维素纤维，因此利用率较低。在本研究中，我们开发了一种温和的三段式碱-氧（AO）工艺，可有效地解构烟草秸秆细胞壁。该工艺在每个阶段分别使用 15%、10%和 3%的碱用量，有效地分离了细胞壁，并获得了具有高亮度（42.0% ISO）的纤维素纤维。废水中的有机物，包括木质素、半纤维素和小分子提取物，通过酸/乙醇沉淀和有机溶剂萃取进行分离。通过 2D HSQC NMR 对木质素进行表征表明，AO 处理后保留了大部分天然的β-芳基醚键，使其适合通过解聚生产化学品或生物燃料。此外，小分子提取物中含有许多来自木质素和碳水化合物的解聚产物，以及来自烟草秸秆的生物活性化合物。总的来说，这种温和、高效和环保的工艺为烟草秸秆和类似生物质资源的增值提供了有前景的方法。
