Sun Ye, Cheng Jay J
Department of Biological and Agricultural Engineering, North Carolina State University, Campus Box 7625, Raleigh, NC 27695-7625, USA.
Bioresour Technol. 2005 Sep;96(14):1599-606. doi: 10.1016/j.biortech.2004.12.022. Epub 2005 Feb 24.
Ethanol production from lignocellulosic materials provides an alternative energy production system. Rye and bermudagrass that are used in hog farms for nutrient uptake from swine wastewater have the potential for fuel ethanol production because they have a relative high cellulose and hemicellulose content. Dilute sulfuric acid pretreatment of rye straw and bermudagrass before enzymatic hydrolysis of cellulose was investigated in this study. The biomass at a solid loading rate of 10% was pretreated at 121 degrees C with different sulfuric acid concentrations (0.6, 0.9, 1.2 and 1.5%, w/w) and residence times (30, 60, and 90 min). Total reducing sugars, arabinose, galactose, glucose, and xylose in the prehydrolyzate were analyzed. In addition, the solid residues were hydrolyzed by cellulases to investigate the enzymatic digestibility. With the increasing acid concentration and residence time, the amount of arabinose and galactose in the filtrates increased. The glucose concentration in the prehydrolyzate of rye straw was not significantly influenced by the sulfuric acid concentration and residence time, but it increased in the prehydrolyzate of bermudagrass with the increase of pretreatment severity. The xylose concentration in the filtrates increased with the increase of sulfuric acid concentration and residence time. Most of the arabinan, galactan and xylan in the biomass were hydrolyzed during the acid pretreatment. Cellulose remaining in the pretreated feedstock was highly digestible by cellulases from Trichoderma reesei.
利用木质纤维素材料生产乙醇提供了一种替代能源生产系统。在养猪场用于从猪废水中吸收养分的黑麦和百慕大草具有生产燃料乙醇的潜力，因为它们的纤维素和半纤维素含量相对较高。本研究考察了在纤维素酶解之前用稀硫酸对黑麦秸秆和百慕大草进行预处理的情况。将固体负载率为10%的生物质在121℃下用不同硫酸浓度（0.6%、0.9%、1.2%和1.5%，w/w）和停留时间（30分钟、60分钟和90分钟）进行预处理。分析了预水解产物中的总还原糖、阿拉伯糖、半乳糖、葡萄糖和木糖。此外，对固体残渣进行纤维素酶水解以研究酶解消化率。随着酸浓度和停留时间的增加，滤液中阿拉伯糖和半乳糖的量增加。黑麦秸秆预水解产物中的葡萄糖浓度不受硫酸浓度和停留时间的显著影响，但随着预处理强度的增加，百慕大草预水解产物中的葡萄糖浓度增加。滤液中木糖浓度随着硫酸浓度和停留时间的增加而增加。生物质中的大部分阿拉伯聚糖、半乳聚糖和木聚糖在酸预处理过程中被水解。预处理原料中残留的纤维素可被里氏木霉的纤维素酶高度消化。
