Canola meal as a novel substrate for β-glucosidase production by Trichoderma viride: application of the crude extract to biomass saccharification.

Abstract

β-Glucosidases are important enzymes with significant prospects in the industrial biotechnology, including their use in biomass hydrolysis for bioethanol production. In this study, the use of canola meal as carbon source for β-glucosidase production by a Trichoderma viride strain in submerged fermentation was evaluated by applying central composite design and response surface methodology to optimize the production process. This statistical approach was also used to improve the passion fruit peel hydrolysis by T. viride crude extract. The model developed 3.6-fold increased β-glucosidase activity. The culture conditions that resulted in the highest β-glucosidase levels were a substrate concentration of 2.9%, pH of medium 4.2 and cultivation time of 206h. The β-glucosidases produced under optimal conditions showed attractive properties for industrial applications, such as activity at high temperatures and stability at 55°C and over a wide pH range. In addition, the enzymatic hydrolysis of passion fruit peel by T. viride crude extract was very promising, resulting in glucose yields of 66.4%. This study, therefore, presents canola meal as an inexpensive and attractive substrate for the production of microbial β-glucosidases.