The lignin present in steam pretreated softwood binds enzymes and limits cellulose accessibility
The lignin present in steam pretreated softwood binds enzymes and limits cellulose accessibility
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DOI：
10.1016/j.biortech.2011.09.091
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发表时间：
2012-01-01
影响因子：
11.4
通讯作者：
Saddler, Jack
中科院分区：
文献类型：
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作者：
Kumar, Linoj;Arantes, Valdeir;Saddler, Jack
研究了纤维素可及性和蛋白质负载量对蒸汽预处理花旗松酶解效率的影响。很明显，木质素组分显著影响纤维素的溶胀/可及性，因为在低蛋白质负载（5 FPU/g纤维素）下，蒸汽预处理的软木中存在的纤维素仅16%被水解，而用脱木质素的底物实现几乎完全水解。当木质素（从蒸汽预处理的道格拉斯冷杉中分离出来）以相同的比例添加回最初发现的高度可接近和溶胀的脱木质素蒸汽预处理的软木和纤维素对照如Avicel时，水解产率分别降低了9%和46%。然而，当采用更高的酶负载时，酶的更大可用性可以克服木质素对纤维素可及性的限制和酶的直接结合所施加的限制，导致纤维素的接近完全水解。(C)2011爱思唯尔有限公司保留所有权利。
The influence of cellulose accessibility and protein loading on the efficiency of enzymatic hydrolysis of steam pretreated Douglas-fir was assessed. It was apparent that the lignin component significantly influences the swelling/accessibility of cellulose as at low protein loadings (5 FPU/g cellulose), only 16% of the cellulose present in the steam pretreated softwood was hydrolyzed while almost complete hydrolysis was achieved with the delignified substrate. When lignin (isolated from steam pretreated Douglas-fir) was added back in the same proportions it was originally found to the highly accessible and swollen, delignified steam pretreated softwood and to a cellulose control such as Avicel, the hydrolysis yields decreased by 9 and 46%, respectively. However, when higher enzyme loadings were employed, the greater availability of the enzyme could overcome the limitations imposed by both the lignin's restrictions on cellulose accessibility and direct binding of the enzymes, resulting in a near complete hydrolysis of the cellulose. (C) 2011 Elsevier Ltd. All rights reserved.