Characterization of β-glucosidases produced by Aspergillus niger atcc 1004 in submerged fermentation from sugarcane bagasse

The cost of commercial enzymes is a limiting factor for the production of bioproducts from lignocellulosic materials, encouraging studies of enzymatic catalysis in order to obtain cellulolytic enzymes from low cost raw materials. A β-glucosidase extract produced by Aspergillus niger ATCC 1004 using submerged fermentation and sugarcane bagasse as carbon source was characterized in terms of stability at different temperatures, activity by combining the effect of pH and temperature, and electrophoretic profile. The enzymatic extract was highly stable at 4°C and 37°C. The highest enzymatic activity were achieved in the temperature and pH range between 47- 52.7°C and 3.6-5.2m, respectively. Two types of β-glucosidases were verified and their weights of 167.9 and 119.0 kDa were estimated by SDS-PAGE. The characteristics presented by the β-glucosidase extract suggests its application in simultaneous saccharification and fermentation processes.

Keywords: lignocellulosic materials, cellulolytic enzymes, thermal stability, enzymatic activity.