Dr. Aniello Costantini
University of Naples Federico II, Italy
Title: Efficient and easy physical co-immobilization procedure of cellulase and β-glucosidase into wrinkled silica nanoparticles for the hydrolysis of cellulose extracted from agricultural waste
Biography
Biography: Dr. Aniello Costantini
Abstract
The efficiency of cellulose hydrolysis is negatively affected by the low amount of β-glucosidase (BG) contained in fungal cellulase enzyme cocktail. So, we implemented a strategy to physically co-immobilize β-glucosidase and cellulase on Wrinkled Mesoporous Silica Nanoparticles (WSNs) to enhance glucose production. WSNs are nanoparticles with radial and hierarchical open pore structure, exhibiting smaller (WSN) and larger (WSN-p) inter-wrinkle distance depending on the synthesis strategy. The immobilization was carried out separately on different vectors (WSN for BG and WSN-p for cellulase); simultaneously on the same vector (WSN-p) and sequentially on the same vector (WSN-p) in order to optimize the synergy between cellulase and BG. The obtained results highlighted that simultaneous immobilization of BG and cellulase on the same vector (WSN-p) results in the best biocatalyst. In this case, the adsorption resulted in 20% yield of immobilization, corresponding to an enzyme loading of 100 mg/g of support. 82% yield of reaction and 72 µmol/min∙g activities were obtained, evaluated for the hydrolysis of cellulose extracted from Eriobotrya japonica leaves. All reactions were carried out at a standard temperature of 50°C. The biocatalyst retained 83% of the initial yield of reaction after 9 cycles of reuse. Moreover, it had better stability than the free enzyme mixture in a wide range of temperatures, preserving 72% of the initial yield of reaction up to 90°C.