Fractionating recalcitrant lignocellulose at modest reaction conditions.
Fractionating recalcitrant lignocellulose at modest reaction conditions.
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DOI：
10.1002/bit.21386
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发表时间：
2007-06
影响因子：
3.8
通讯作者：
Y. Zhang;S. Ding;J. Mielenz;Jing-Biao Cui;R. Elander;M. Laser;M. Himmel;J. McMillan;L. Lynd
中科院分区：
文献类型：
--
作者：
Y. Zhang;S. Ding;J. Mielenz;Jing-Biao Cui;R. Elander;M. Laser;M. Himmel;J. McMillan;L. Lynd
将顽固的木质纤维素中的锁定多糖有效地释放到可发酵的糖中是实现木质纤维素生物炼制的最大技术和经济障碍之一，因为主要的木质纤维素预处理技术存在糖产量低、反应条件苛刻、纤维素酶用量高、底物适用性窄、资本投资高等问题。采用不挥发性纤维素溶剂（浓磷酸）、高挥发性有机溶剂（丙酮）和水，在适度反应条件（50℃和常压）下，将木质纤维素分馏成无定形纤维素、半纤维素、木质素和乙酸。酶解后的最高糖产量归因于在分离过程中没有糖降解，在酶解步骤中，酶解纤维素的酶消化率最高（24 h内约97%），酶负荷为15滤纸单位纤维素酶和每克葡聚糖60 IU β -葡萄糖苷酶。分离高价值的木质纤维素成分（木质素、乙酸和半纤维素）将大大增加木质纤维素生物精炼厂的潜在收入。
Effectively releasing the locked polysaccharides from recalcitrant lignocellulose to fermentable sugars is among the greatest technical and economic barriers to the realization of lignocellulose biorefineries because leading lignocellulose pre-treatment technologies suffer from low sugar yields, and/or severe reaction conditions, and/or high cellulase use, narrow substrate applicability, and high capital investment, etc. A new lignocellulose pre-treatment featuring modest reaction conditions (50 degrees C and atmospheric pressure) was demonstrated to fractionate lignocellulose to amorphous cellulose, hemicellulose, lignin, and acetic acid by using a non-volatile cellulose solvent (concentrated phosphoric acid), a highly volatile organic solvent (acetone), and water. The highest sugar yields after enzymatic hydrolysis were attributed to no sugar degradation during the fractionation and the highest enzymatic cellulose digestibility ( approximately 97% in 24 h) during the hydrolysis step at the enzyme loading of 15 filter paper units of cellulase and 60 IU of beta-glucosidase per gram of glucan. Isolation of high-value lignocellulose components (lignin, acetic acid, and hemicellulose) would greatly increase potential revenues of a lignocellulose biorefinery.