漆酶活化玉米秸秆木质素的研究

发布时间：2018-05-07 16:49

  本文选题：玉米秸秆木质素 + 漆酶　； 参考：《东北林业大学》2016年硕士论文

【摘要】：本文以漆酶和漆酶/介体体系在有氧条件下对玉米秸秆木质素进行活化处理,选用了混合溶剂体系,有效解决了玉米秸秆木质素难溶于水的问题,通过活化处理,提高了玉米秸秆木质素的羟基含量,降低了其相对分子质量,提高了反应活性。(1)本文首先使用漆酶单独活化处理玉米秸秆木质素,选用了二氧六环/水、聚乙二醇/水、磺酸盐木质素/水三种溶剂体系,利用傅立叶变换红外光谱(FT-IR)、紫外可见分光光度计、GPC和TGA进行微观分析和表征,探究了处理时间(t)、体系pH值、处理温度(T)和漆酶用量(漆酶酶活/木质素质量)对活化处理效果的影响,从而确定了适宜的活化处理条件为处理时间为1.5-2h,体系pH值为4.0-4.5,处理温度为40℃,漆酶用量为25U/g。(2)用漆酶在三种体系对应的最适活化处理条件下活化处理玉米秸秆木质素,对比分析了三种混合溶剂中活化处理效果的优劣程度,确定了最佳的混合溶剂体系为聚乙二醇/水混合溶剂,此体系下最佳的活化处理条件为处理时间1.5h,体系pH值为4.0,处理温度为40℃,漆酶用量为25U/g,可将木质素羟基含量由3.6%提升至4.3%,并利用DSC测试证明,活化后的玉米秸秆木质素与饱和脂肪酸的酯化反应能力提高。(3)选用了三种介体(HBT、紫丁香醛、香草醛),使用漆酶/介体体系在聚乙二醇/水混合溶剂体系中以最适宜处理条件对玉米秸秆木质素进行活化处理,实验证明,漆酶/介体体系活化处理可以进一步降解玉米秸秆木质素,使高分子量木质素发生断链降解,其中漆酶/HBT介体体系活化处理玉米秸秆木质素,可将木质素羟基含量由3.6%提升至4.6%,高分子量木质素含量进一步减少,与漆酶单独活化处理的玉米秸秆木质素相比,漆酶/HBT体系活化木质素与饱和脂肪酸的酯化反应能力进一步增强。
[Abstract]:In this paper, laccase and laccase / medium system were used to activate corn straw lignin under aerobic conditions, and mixed solvent system was used to effectively solve the insoluble water problem of corn stalk lignin. The hydroxyl content of corn straw lignin was increased, the relative molecular weight of lignin was decreased, and the reaction activity was improved. (1) in this paper, the lignin of corn straw was treated by laccase alone, dioxane / water, polyethylene glycol / water were selected. The sulfonate lignin / water system was characterized by Fourier transform infrared spectroscopy (FTIR), UV-Vis spectrophotometer and TGA. The treatment time and pH value of the system were investigated. The effects of temperature (T) and laccase dosage (laccase activity / lignin quality) on the activation treatment were determined. The optimum conditions of activation treatment were as follows: treatment time 1.5-2h, pH 4.0-4.5, treatment temperature 40 鈩，

本文编号：1857693