Neutron Reflectometry and QCM-D Study of the Interaction of Cellulases with Films of Amorphous Cellulose

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• 作者：Gang Cheng ; Zelin Liu ; Jaclyn K. Murton ; Michael Jablin ; Manish Dubey ; Jaroslaw Majewski ; Candice Halbert ; James Browning ; John Ankner ; Bulent Akgun ; Chao Wang ; Alan R. Esker ; Kenneth L. Sale ; Blake A. Simmons ; Michael S. Kent
• 刊名：Biomacromolecules
• 出版年：2011
• 出版时间：June 13, 2011
• 年：2011
• 卷：12
• 期：6
• 页码：2216-2224
• 全文大小：1007K
• 年卷期：v.12,no.6(June 13, 2011)
• ISSN：1526-4602

文摘

Improving the efficiency of enzymatic hydrolysis of cellulose is one of the key technological hurdles to reduce the cost of producing ethanol and other transportation fuels from lignocellulosic material. A better understanding of how soluble enzymes interact with insoluble cellulose will aid in the design of more efficient enzyme systems. We report a study involving neutron reflectometry (NR) and quartz crystal microbalance with dissipation monitoring (QCM-D) of the interaction of a fungal enzyme extract (T. viride) and an endoglucanse from A. niger with amorphous cellulose films. The use of amorphous cellulose is motivated by that the fact that several biomass pretreatments currently under investigation disrupt the native crystalline structure of cellulose and increase the amorphous content. NR reveals the profile of water through the film at nanometer resolution and is highly sensitive to interfacial roughness, whereas QCM-D provides changes in mass and film stiffness. NR can be performed using either H₂O- or D₂O-based aqueous reservoirs. NR measurement of swelling of a cellulose film in D₂O and in H₂O revealed that D/H exchange on the cellulose chains must be taken into account when a D₂O-based reservoir is used. The results also show that cellulose films swell slightly more in D₂O than in H₂O. Regarding enzymatic digestion, at 20 掳C in H₂O buffer the T. viride cocktail rapidly digested the entire film, initially roughening the surface, followed by penetration and activity throughout the bulk of the film. In contrast, over the same time period, the endoglucanase was active mainly at the surface of the film and did not increase the surface roughness.