Chemical and Environmental Engineering Department, University of California, Riverside, CA 92506, USA.
Bioresour Technol. 2011 Dec;102(24):11052-62. doi: 10.1016/j.biortech.2011.06.069. Epub 2011 Jun 21.
Dilute sulfuric acid (DA), sulfur dioxide (SO(2)), liquid hot water (LHW), soaking in aqueous ammonia (SAA), ammonia fiber expansion (AFEX), and lime pretreatments were applied to Alamo, Dacotah, and Shawnee switchgrass. Application of the same analytical methods and material balance approaches facilitated meaningful comparisons of glucose and xylose yields from combined pretreatment and enzymatic hydrolysis. Use of a common supply of cellulase, beta-glucosidase, and xylanase also eased comparisons. All pretreatments enhanced sugar recovery from pretreatment and subsequent enzymatic hydrolysis substantially compared to untreated switchgrass. Adding beta-glucosidase was effective early in enzymatic hydrolysis while cellobiose levels were high but had limited effect on longer term yields at the enzyme loadings applied. Adding xylanase improved yields most for higher pH pretreatments where more xylan was left in the solids. Harvest time had more impact on performance than switchgrass variety, and microscopy showed changes in different features could impact performance by different pretreatments.
稀硫酸（DA）、二氧化硫（SO(2)）、液态热水（LHW）、氨水溶液浸泡（SAA）、氨纤维膨胀（AFEX）和石灰预处理应用于 Alamo、Dacotah 和 Shawnee 柳枝稷。采用相同的分析方法和物料平衡方法，有助于对组合预处理和酶解的葡萄糖和木糖产率进行有意义的比较。使用相同的纤维素酶、β-葡萄糖苷酶和木聚糖酶供应也便于进行比较。与未处理的柳枝稷相比，所有预处理都大大提高了预处理和后续酶解过程中的糖回收率。在酶解过程中早期添加β-葡萄糖苷酶在纤维二糖水平较高时效果显著，但在应用的酶负荷下对长期产率影响有限。添加木聚糖酶对较高 pH 值预处理的效果最佳，因为在固体中留下了更多的木聚糖。收获时间对性能的影响大于柳枝稷品种，显微镜观察显示不同预处理对不同特征的变化会影响性能。
