School of Chemistry and Biochemistry, Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Bioresour Technol. 2011 Jul;102(14):7224-8. doi: 10.1016/j.biortech.2011.04.029. Epub 2011 Apr 14.
Hydrothermal pretreatment was performed on the leaves and internodes portions of Alamo switchgrass, Panicum virgatum L., to enhance the digestibility of cellulose towards cellulase. It was observed that extractives free leaves portion provided 18.1% lower pretreatment gravimetrical yield and 33.8% greater cellulose-to-glucose yield than internodes portion. The degree of polymerization (DP) and ultrastructure of cellulose were determined by gel-permeation chromatography and solid-state cross polarization/magic angle spinning (13)C NMR experiments. The results suggested that hydrothermal pretreatment hydrolyzed amorphous cellulose and yielded a product enriched in paracrystalline cellulose. Furthermore, the DP of cellulose was reduced to one third of the origin value after hydrothermal pretreatment. The resulting biomass after pretreatment for leaves and internodes has similar cellulose ultrastructure and chemical profiles. The results of the enzymatic hydrolysis studies of cellulose suggest that the reduced DP of cellulose of pretreated switchgrass was an important factor influencing the enhanced digestibility of pretreated switchgrass.
对 Alamo 柳枝稷（ Panicum virgatum L.）的叶片和节间部分进行水热预处理，以提高纤维素对纤维素酶的消化率。结果表明，与节间部分相比，无抽提物的叶片部分的预处理重量产率低 18.1%，而纤维素到葡萄糖的产率高 33.8%。通过凝胶渗透色谱和固态交叉极化/魔角旋转（ 13）C NMR 实验测定了纤维素的聚合度（ DP）和超微结构。结果表明，水热预处理水解了无定形纤维素，并得到了富含准晶纤维素的产物。此外，纤维素的 DP 在水热预处理后降低到原始值的三分之一。预处理后的叶片和节间生物质具有相似的纤维素超微结构和化学特征。纤维素的酶水解研究结果表明，预处理柳枝稷纤维素的 DP 降低是影响预处理柳枝稷消化率提高的一个重要因素。
