Comparative study for enzymatic hydrolysis of sugarcane bagasse using free and nanoparticle immobilized holocellulolytic enzyme cocktail

Abstract

This study aimed at a comparative analysis of enzymatic hydrolysis of sugarcane bagasse biomass by using a free holocellulase cocktail of an enzyme (Cellic CTec2) and immobilized enzyme system on IOMNP@SiO2-NH2 support to make the process cost-effective. The immobilization was substantiated by examining the nano biocatalysts using FTIR, TEM, and DLS analysis. IOMNP@SiO2 –NH2 and immobilized enzyme system have average particle sizes of 81.1, and 455.9 nm confirmed by DLS. Response surface methodology (RSM) based on the Box Behnken design was employed to optimize the saccharification process conditions. The free cellulase cocktail showed a maximum hydrolysis yield of 70.71 % at 12.5FPU/gm enzyme dose, while the immobilized enzyme at a dose of 20 FPU/gm achieved a conversion rate of 74.19 % under optimized parameters likes hydrolysis time, surfactant and substrate concentration. Pretreated sugarcane bagasse substrate was used to evaluate the reusability potential of magnetically immobilized cellulase enzyme compared to recovered free enzyme up to 5 cycles. In the second and third cycles, the conversion rates of cellulose to glucose were determined to be 68.21 %, and 52.6 %, respectively. The findings of this study demonstrate that the immobilized Cellic CTec2 enzyme cocktail on functionalized IOMNP is effective for hydrolyzing sugarcane bagasse which also provides the advantages of easy recovery and reusability of enzyme for multiple hydrolysis cycles.