Electrospun chitosan coated polylactic acid nanofiber: A novel immobilization matrix for α – Amylase and its application in hydrolysis of cassava fibrous waste

Abstract

This present study addresses the uncherished resource potential of Cassava fibrous waste (CFW) from the cassava processing industry towards production of fermentable sugars using enzymatic hydrolysis process. However, the viscous nature of the gelatinized CFW poses serious processability issues, which was overcome by a novel attempt of using tailor-made electrospun nanofibers and its application in immobilization of α – amylase. Characterization studies (FESEM, FTIR, Thermogravimetric analysis), rheological and proximate analysis of CFW revealed its suitability as the potential feedstock. Chitosan coated nanofiber (CCN) matrix was prepared by varying the chitosan concentration from 0 to 2% (w/v) and the 2% CCN matrix exhibited an optimal performance with enhanced tensile strength (1.262 MPa), reduced elongation (41.2%) and contact angle (128°). CCN matrix was examined for the immobilization of α - amylase enzyme and the relative activities of the immobilized and free enzyme were compared. Packed bed operation at optimized conditions (solution pH of 5.0 and a solution temperature of 50 °C) deploying CCN matrix with initial substrate concentration of 10 g/l yielded a maximum conversion ratio of 0.85 and 0.99 (high residence time of 40 min and low dilution rate of 0.04 min−1) for without and with recycling mode, respectively.

Keywords

• Cassava fibrous waste
• Electrospun matrix
• Enzymatic hydrolysis
• Immobilization
• Nanofiber
• Characterization