NaOH对类芬顿预处理的玉米秸秆酶解性能影响  

Effect of NaOH on enzymatic hydrolysis performance of corn stover treated with heterogeneous Fenton pretreatment

作　　者：李梦洁 张凤娇 李甜乐 杨鹏飞 吕东灿[2] 姜广策 王志敏[2] 张宏森 毛国涛 宋安东[1] LI Mengjie;ZHANG Fengjiao;LI Tianle;YANG Pengfei;L Dongcan;JIANG Guangce;WANG Zhimin;ZHANG Hongsen;MAO Guotao;SONG Andong(Key Laboratory of Enzyme Engineering of Agricultural Microbiology,Ministry of Agriculture and Rural Affairs,College of Life Sciences,Henan Agricultural University,Zhengzhou 450046,China;College of Science,Henan Agricultural University,Zhengzhou 450002,China)

机构地区：[1]河南农业大学生命科学学院/农业农村部农业微生物酶工程重点实验室,河南郑州450046 [2]河南农业大学理学院,河南郑州450002

出　　处：《河南农业大学学报》2023年第5期844-852,共9页Journal of Henan Agricultural University

基　　金：国家重点研发计划项目(2021YFD1700900);河南省高校科技创新人才支持计划(18HASTIT038);大学生创新创业训练项目(2022DC175)。

摘　　要：【目的】探究NaOH对类芬顿预处理(heterogeneous Fenton pretreatment,HFP)的玉米秸秆酶解效果影响及高效酶解的机制。【方法】在HFP体系(0.16 g·L^(-1)FeOCl,0.8 mol·L^(-1)H_(2)O_(2),6 h)对玉米秸秆预处理的前期进行NaOH前处理,以酶解后还原糖产率为指标,考察NaOH浓度和反应温度对NaOH-HFP体系的影响。对比未处理玉米秸秆和3种不同预处理体系(HFP体系、NaOH预处理体系和NaOH-HFP体系)处理后玉米秸秆的理化表征(成分分析和结构表征)。【结果】当NaOH浓度0.1 mol·L^(-1),反应温度75℃时,经NaOH-HFP体系预处理玉米秸秆酶解后还原糖产率为92.5%,分别比NaOH预处理体系及HFP体系提高了31.0%和181.2%。成分分析结果表明,NaOH-HFP体系能够去除部分半维素和木质素。扫描电子显微镜、X-射线衍射、固态核磁和比表面积和孔隙率分析表征结果表明,预处理没有造成底物表面化学结构显著变化,但表面形态和结晶度变化显著,从而增强了酶对纤维素的可及性,提高了酶解效率。【结论】NaOH-HFP体系实现了对木质素的有效降解,打破了碳水化合物酶解屏障。【Objective】To study the effect of NaOH on the enzymatic hydrolysis of corn stover in heterogeneous Fenton pretreatment(HFP),and to explore the mechanism of efficient enzymatic hydrolysis.【Method】In HFP systems(0.16 g·L^(-1) FeOCl,0.8 mol·L^(-1) H_(2)O_(2),6 h),NaOH pretreatment was performed in the early stage of corn stover pretreatment,and the effects of NaOH concentration and reaction temperature on the NaOH-HFP system were investigated by reducing sugar yield after enzymatic hydrolysis.The physicochemical characterization(composition analysis and structural characterization)of corn stover was compared in untreated system and three different pretreatment systems(HFP system,NaOH pretreatment system and NaOH-HFP system).【Result】The suitable conditions of NaOH in NaOH-HFP system were as follows:NaOH concentration 0.1 mol·L^(-1),reaction temperature 75℃ and reaction time 2 h.The total sugar yield was 92.5%of the theoretical yield.Compared with NaOH pretreatment system and HFP system alone,the total sugar yield increased by 31.0%and 181.2% respectively.The results of composition analysis showed that NaOH-HFP system could partially remove hemicellulose and lignin.The results of scanning electron microscope,diffraction of X-rays,solid-state NMR,and specific surface area and porosity analysis showed that pretreatment did not cause significant changes of chemical structure in the substrate surface,but the surface morphology and crystallinity changed significantly.These changes enhance the accessibility of enzymes to cellulose and improve the efficiency of enzymatic hydrolysis.【Conclusion】The NaOH-HFP system could effectively degrade lignin,break the barrier of carbohydrate enzymatic hydrolysis and improve the enzymatic hydrolysis efficiency.

关 键 词：木质纤维素 玉米秸秆 类芬顿预处理 酶解 还原糖 

分 类 号：S216.2[农业科学—农业机械化工程]