Biomass & Bioenergy, Vol.122, 481-489, 2019
Increase of reducing sugars release by enzymatic hydrolysis of sugarcane bagasse intensified by ultrasonic treatment
The purpose of this study was to evaluate the effect of ultrasonic treatment on the activity of commercial cellulases and on the efficiency of the enzymatic hydrolysis of sugarcane bagasse. The influence of ultrasound on the hydrolysis of sugarcane bagasse (2% w v(-1)) was assessed using commercial enzymes (Celluclase (R) 1.5 L and Cellic (R) CTec2) in a central composite rotatable design (CCRD) to determine the effect of ultrasound intensity, time and temperature of reaction medium. The enzymatic hydrolysis of sugarcane bagasse was enhanced by the application of ultrasound, leading to an 89.37% higher concentration of reducing sugars in comparison with the control (unsonicated sample) under the optimal conditions validated for Celluclast 1.5 L (150.7 W cm(-2), 330 s, 25 degrees C). A high concentration of reducing sugars (91.81% higher than the control) and a 66.31% theoretical cellulose yield were obtained using the enzyme cocktail Cellic CTec2 under optimal conditions (150.7 W cm(-2), 75 s, 30 degrees C). Ultrasonication under appropriate conditions led to favorable results: increased catalytic activity of cellulases and increased degree of hydrolysis of the lignocellulosic substrate. These results evidence the potential of ultrasonic treatment in improving the performance of enzyme cocktails used for the hydrolysis of sugarcane bagasse.