不同方法预处理的玉米秸秆结构与酶解分析

Structure and Enzymatic Hydrolysis Analysis of Corn Stover Pretreated with Different Pretreatment Methods

在利用秸秆进行工业转化时,因为秸秆结构复杂,导致转化效率低,所以需对秸秆进行预处理,破坏秸秆复杂结构,提高转化效率。采用扫描电镜(SEM)、傅里叶变换红外光谱(FT-IR)和X射线衍射技术分析不同预处理方式对玉米秸秆微观结构的影响,并利用纤维素酶对不同预处理秸秆进行酶解,评价预处理效果。扫描电镜结果表明,不同预处理方式对秸秆表面形态和秸秆整体结构造成不同程度的破坏,其中NaOH预处理后的秸秆表面结构坍塌明显,表明木质纤维素结构被有效打破。利用傅里叶变换红外光谱对不同预处理方式的秸秆进行分析,其中1600和1510cm^(-1)为木质素的特征峰,NaOH预处理后的秸秆在此处的特征峰基本消失,表明NaOH预处理对秸秆木质素的去除效率比较明显。1744~1734 cm^(-1)为C=O伸缩振动特征峰,此峰的强度与木质素和半纤维素的含量有关,采用不同方法预处理后,此峰的吸收强度不同程度地减少,表明各种预处理方法不同程度地去除了秸秆的木质素和半纤维素。X-射线衍射分析表明,不同预处理后秸秆的结晶度均发生不同程度的改变,其中H_2SO_4预处理后秸秆的结晶度提高最大,达到43.4%。其中NaOH预处理秸秆后,用纤维素酶酶解60h,使其酶解产糖量达到33.32g/L。本研究分析了不同秸秆预处理方法的效果,为利用玉米秸秆生产生物化工产品提供了理论依据。

In the process of industrial transformation of straw,due to the complicated structural relationship of straw itself,the conversion efficiency is low.Therefore,different pretreatment methods are required to pretreat straw to destroy the inherent structure of the straw and improve its enzymatic efficiency.In this study,the effects of different pretreatments on the microstructure of corn stover were investigated by scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR)and X-ray diffraction(XRD).Moreover,the hydrolysis of different pretreated corn stover with cellulase was studied.It was showed that the surface and structure of corn stover were damaged in some extent in pretreatment.The surface of corn stover pretreated with NaOH collapsed mostly,which showed that the structure of lignocellulose was broken effectively.The pretreated corn stover was analyzed with Fourier transform infrared spectroscopy.It was show that the characteristic peaks of ligin at 1600 and 1510 cm 0x0E?Symbolm@@0x0F1 disappeared for corn stover pretreated with NaOH,which indicated that the lignin was removed effectively.The peaks at 1744-1734 cm 0x0E Symbolm@@0x0F1 of pretreated corn stovers(the characteristic peak of C O),which related to ligin and hemicellulose,reduced in different extent.It was shown that the lignin and hemicellulose were removed with different pretreated methods.Moreover,it was shown that the crystallinities of pretreated corn stovers changed in different extent with X-ray scanning.The crystallinity of corn stover pretreated with H 2SO 4 got the maxium value of 43.4%.The effects of different pretreated methods were evaluated with corn stover hydrolysis by cellulase.The maxium value of glucose was 33.32 g/L.This study provided basis for the efficient production of biochemicals with different pretreated corn stover.