Laureano-Perez Lizbeth, Teymouri Farzaneh, Alizadeh Hasan, Dale Bruce E
Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI, 48824, USA.
Appl Biochem Biotechnol. 2005 Spring;121-124:1081-99. doi: 10.1385/abab:124:1-3:1081.
Spectroscopic characterization of both untreated and treated material is being performed in order to determine changes in the biomass and the effects of pretreatment on crystallinity, lignin content, selected chemical bonds, and depolymerization of hemicellulose and lignin. The methods used are X-ray diffraction for determination of cellulose crystallinity (CrI); diffusive reflectance infrared (DRIFT) for changes in C-C and C-O bonds; and fluorescence to determine lignin content. Changes in spectral characteristics and crystallinity are statistically correlated with enzymatic hydrolysis results to identify and better understand the fundamental features of biomass that govern its enzymatic conversion to monomeric sugars. Models of the hydrolysis initial rate and 72 h extent of conversion were developed and evaluated. Results show that the hydrolysis initial rate is most influenced by the cellulose crystallinity, while lignin content most influences the extent of hydrolysis at 72 h. However, it should be noted that in this study only crystallinity, lignin, and selected chemical bonds were used as inputs to the models. The incorporation of additional parameters that affect the hydrolysis, like pore volume and size and surface area accessibility, would improve the predictive capability of the models.
为了确定生物质的变化以及预处理对结晶度、木质素含量、选定化学键以及半纤维素和木质素解聚的影响，正在对未处理和已处理的材料进行光谱表征。所使用的方法包括：用X射线衍射测定纤维素结晶度（CrI）；用漫反射红外光谱（DRIFT）测定C-C键和C-O键的变化；用荧光法测定木质素含量。光谱特征和结晶度的变化与酶水解结果进行统计关联，以识别并更好地理解生物质中控制其酶转化为单糖的基本特征。建立并评估了水解初始速率和72小时转化程度的模型。结果表明，水解初始速率受纤维素结晶度的影响最大，而木质素含量对72小时水解程度的影响最大。然而，应当指出的是，在本研究中，仅将结晶度、木质素和选定的化学键用作模型的输入参数。纳入影响水解的其他参数，如孔体积、尺寸和表面积可及性，将提高模型的预测能力。
