Nguyen Thanh Yen, Cai Charles M, Kumar Rajeev, Wyman Charles E
Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California, Riverside, 1084 Columbia Avenue, Riverside, California 92507 (USA), Fax: (+1) 951-781-5790.
Department of Bioengineering, Bourns College of Engineering, University of California, Riverside, 217 Materials Science & Engineering, 900 University Ave., Riverside, CA 92507 (USA).
ChemSusChem. 2015 May 22;8(10):1716-25. doi: 10.1002/cssc.201403045. Epub 2015 Feb 11.
We introduce a new pretreatment called co-solvent-enhanced lignocellulosic fractionation (CELF) to reduce enzyme costs dramatically for high sugar yields from hemicellulose and cellulose, which is essential for the low-cost conversion of biomass to fuels. CELF employs THF miscible with aqueous dilute acid to obtain up to 95 % theoretical yield of glucose, xylose, and arabinose from corn stover even if coupled with enzymatic hydrolysis at only 2 mgenzyme gglucan (-1) . The unusually high saccharification with such low enzyme loadings can be attributed to a very high lignin removal, which is supported by compositional analysis, fractal kinetic modeling, and SEM imaging. Subsequently, nearly pure lignin product can be precipitated by the evaporation of volatile THF for recovery and recycling. Simultaneous saccharification and fermentation of CELF-pretreated solids with low enzyme loadings and Saccharomyces cerevisiae produced twice as much ethanol as that from dilute-acid-pretreated solids if both were optimized for corn stover.
我们引入了一种名为共溶剂增强木质纤维素分级分离（CELF）的新预处理方法，以大幅降低酶成本，从而从半纤维素和纤维素中获得高糖产量，这对于将生物质低成本转化为燃料至关重要。CELF使用与稀酸水溶液互溶的四氢呋喃（THF），即使仅在2 mg酶/g葡聚糖（-1）的条件下与酶水解相结合，也能从玉米秸秆中获得高达95%的葡萄糖、木糖和阿拉伯糖理论产量。如此低的酶负载量却能实现异常高的糖化率，这可归因于极高的木质素去除率，成分分析、分形动力学建模和扫描电子显微镜成像均证实了这一点。随后，通过蒸发挥发性的THF可沉淀出近乎纯的木质素产品，以便回收和循环利用。如果针对玉米秸秆进行优化，用低酶负载量的CELF预处理固体与酿酒酵母进行同步糖化发酵，产生的乙醇量是稀酸预处理固体的两倍。
