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

• Published in: AIMS bioengineering 2016-01, Vol.3 (4), p.441-453
• Main Authors: P. Nghiem, Nhuan, W. Ellis, Jr, Clyde, Montanti, Justin
• Format: Article
• Language: English
• Subjects: biorefinery; cellulosic conversion; commercial cellulases; ethanol; lignocellulosic feedstocks; simultaneous saccharification and fermentation
• ISSN: 2375-1495
• DOI: 10.3934/bioeng.2016.4.441

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.