Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China.
State Key Laboratory of Bio-Fibers and Eco-Textiles (Qingdao University), Qingdao 266000, People's Republic of China.
Bioresour Technol. 2020 Sep;311:123517. doi: 10.1016/j.biortech.2020.123517. Epub 2020 May 11.
To overcome the recalcitrance of residual lignins in acid-pretreated larch (AL), a combined acid and alkali pretreatment with in-situ lignin modification was developed in this study. The results showed that introducing in-situ lignin modification with 2-naphthol to acid pretreatment (160 and 180 C) improved the enzymatic digestibility of AL by 12.7-14.4%, through suppressing lignin repolymerization. The obviously higher improvement (57.8-88.3%) was achieved by applying alkali post-treatment (90 C) with poly (ethylene glycol) diglycidyl ether (PEGDE) on AL, mainly due to the function of in-situ lignin modification with PEGDE for reducing enzyme non-productive binding on lignins. More importantly, the synergism of 2-naphthol and PEGDE modification facilitated the enzymatic hydrolysis of AL more significantly. Its beneficial mechanism was explored by investigating the effects of in-situ lignin modification on lignin properties, including extraction yields, functional groups, and enzyme affinity of lignins. Results will give insights into establishing an efficient pretreatment of softwood biomass.
为克服酸预处理落叶松（AL）中残留木质素的顽固性，本研究开发了一种结合酸和碱预处理及原位木质素修饰的方法。结果表明，在 160 和 180°C 的酸预处理中引入 2-萘酚原位木质素修饰，可通过抑制木质素的重新聚合，将 AL 的酶解糖化率提高 12.7-14.4%。通过在 AL 上用聚乙二醇二缩水甘油醚（PEGDE）进行 90°C 的碱后处理，可实现明显更高的改善（57.8-88.3%），主要归因于 PEGDE 的原位木质素修饰减少了酶对木质素的非生产性结合。更重要的是，2-萘酚和 PEGDE 修饰的协同作用更显著地促进了 AL 的酶水解。通过研究原位木质素修饰对木质素性质（包括木质素的提取产率、官能团和酶亲和力）的影响，探讨了其有益机制。研究结果将为建立有效的软木生物质预处理方法提供新的思路。
