Pre-treatments applied to rice husk enzymatic hydrolysis: effect on structure, lignocellulosic components, and glucose production kinetics

Published in: Engineering, Integration, and Alliances for a Sustainable Development. Hemispheric Cooperation for Competitiveness and Prosperity on a Knowledge-Based Economy: Proceedings of the 18th LACCEI International Multi-Conference for Engineering, Education and Technology
Date of Conference: July 27-31, 2020
Location of Conference: Virtual
Authors: Guillermo Linares Luján (Universidad Nacional de Trujillo, PE)
Meliza Lindsay Rojas (Universidad Privada del Norte, PE)
Jesús A. Sánchez-González (Universidad Nacional de Trujillo, PE)
Leslie Lescano Bocanegra (Universidad Nacional de Trujillo, PE)
Sandra Pagador Flores (Universidad César Vallejo, PE)
Fernando Aredo (Universidad César Vallejo, PE)
Full Paper: #42

Abstract:

Freezing (-20 °C, 12h) and alkaline (NaOH 8%) pre-treatments were applied individually and combined in rice husk (Oryza sativa L.) before their hydrolysis with cellulase (EC: 3.2.1.4.). The effects on structural modifications, lignin content, cellulose, hemicellulose content and glucose production were evaluated. In addition, the glucose production kinetics were described by using the Peleg model. The homogenous rice husk (1 g) with and without pre-treatments was hydrolysed with 150 U of Cellulase in 10 ml of acetate for 60 h (37 °C, pH 5.5, 100 rpm). As results, the SEM images evidenced porous microstructures with less agglomeration generated by all pre-treatments, which were intensified by the combined pre-treatment. This pre-treatment allowed to obtain higher cellulose (62.51 ± 0.3 %) content. Besides, the glucose content after pre-treatments increased. The Peleg model parameters from glucose production kinetics during enzymatic hydrolysis were related to initial glucose content (G0), glucose production rate (1/k1) and maximum glucose yield (1/k2). After enzymatic hydrolysis process, compared to control glucose yield (0.359 ± 0.002 g G/g rice husk), this was 27%, 71% and 88% higher for freezing, alkaline and combined pre-treatments respectively.