AIMS Bioengineering, 2016, 3(4): 441-453. doi: 10.3934/bioeng.2016.4.441.

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The effects of ethanol on hydrolysis of cellulose and pretreated barley straw by some commercial cellulolytic enzyme products

1 Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Wyndmoor, Pennsylvania, 19038, USA
2 National Institute of Food and Agriculture, U.S. Department of Agriculture, Washington, District of Columbia, 20024, USA
3 DuPont Engineering Research and Technology, Wilmington, Delaware, 19803, USA

The effect of ethanol at levels ranging from 2.5% v/v to 15% v/v on the activities of two recently developed commercial cellulosic biomass hydrolytic enzyme products, Accellerase® 1500 and Accellerase® XY, was investigated. The substrates used for study of the effect of ethanol on Accellerase® 1500 included α-cellulose, cellobiose and barley straw pretreated by the soaking in aqueous ammonia method. The initial rates of glucose production and final glucose concentrations obtained at 48 h of hydrolysis were used as the response factors. To study the effect of ethanol on Accellerase® XY, beechwood xylan and the pretreated barley straw were used as substrates. The response factors included the initial rates of xylose production and final xylose concentrations obtained at 48 h of hydrolysis. It was found that ethanol acted as either activator or inhibitor depending on its concentration and the type of substrate used. At 10% v/v, which is expected to be the final concentration of ethanol in a commercial cellulosic biomass-based process, ethanol acted as an inhibitor in all cases. However, even at this ethanol level, both commercial enzymes still retained at least about 50% of their activities.
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Keywords lignocellulosic feedstocks; cellulosic conversion; commercial cellulases; ethanol; simultaneous saccharification and fermentation; biorefinery

Citation: Nhuan P. Nghiem, Clyde W. Ellis. Jr, Justin Montanti. The effects of ethanol on hydrolysis of cellulose and pretreated barley straw by some commercial cellulolytic enzyme products. AIMS Bioengineering, 2016, 3(4): 441-453. doi: 10.3934/bioeng.2016.4.441


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