Optimization of ammonia fiber expansion (AFEX) pretreatment and enzymatic hydrolysis of Miscanthus x giganteus to fermentable sugars
Optimization of ammonia fiber expansion (AFEX) pretreatment and enzymatic hydrolysis of Miscanthus x giganteus to fermentable sugars
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DOI：
10.1021/bp070098m
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发表时间：
2007-07-01
影响因子：
2.9
通讯作者：
Dale, Bruce E.
中科院分区：
文献类型：
--
作者：
Murnen, Hannah K.;Balan, Venkatesh;Dale, Bruce E.
芒草是一种高大的多年生草本植物，目前正在评估其作为能源作物的适宜性。关于芒草的预处理和酶促糖化产生可发酵糖的效果的信息非常少。本文报道了经氨纤维膨胀 (AFEX) 预处理的芒草酶水解过程中的糖产量。改变预处理条件，包括温度、湿度、氨负荷、停留时间和酶负荷，以最大限度地提高水解产量。此外，还尝试了进一步的处理，例如在 AFEX 之前浸泡生物质以及清洗预处理的材料，以提高糖产量。确定的最佳 AFEX 条件为 160 摄氏度、2:1 (w/w) 氨与生物质负载、233% 水分（基于干重）以及水浸芒草的 5 分钟反应时间。使用 15 FPU/（克葡聚糖）的纤维素酶和 64 p-NPGU/（克葡聚糖）的 β-葡萄糖苷酶以及补充木聚糖酶和 tween-80，在 1% 葡聚糖负载量下进行 168 小时酶水解后，可实现约 96% 葡聚糖和 81% 木聚糖转化。介绍了 AFEX 预处理和酶水解过程的质量平衡。
Miscanthus x giganteus is a tall perennial grass whose suitability as an energy crop is presently being appraised. There is very little information on the effect of pretreatment and enzymatic saccharification of Miscanthus to produce fermentable sugars. This paper reports sugar yields during enzymatic hydrolysis from ammonia fiber expansion (AFEX) pretreated Miscanthus. Pretreatment conditions including temperature, moisture, ammonia loading, residence time, and enzyme loadings are varied to maximize hydrolysis yields. In addition, further treatments such as soaking the biomass prior to AFEX as well as washing the pretreated material were also attempted to improve sugar yields. The optimal AFEX conditions determined were 160 degrees C, 2:1 (w/w) ammonia to biomass loading, 233% moisture (dry weight basis), and 5 min reaction time for water-soaked Miscanthus. Approximately 96% glucan and 81% xylan conversions were achieved after 168 h enzymatic hydrolysis at 1% glucan loading using 15 FPU/(g of glucan) of cellulase and 64 p-NPGU/(g of glucan) of beta-glucosidase along with xylanase and tween-80 supplementation. A mass balance for the AFEX pretreatment and enzymatic hydrolysis process is presented.