Carbon nanotubes tuned foam structures as novel nanostructured biocarriers for lignocellulose hydrolysis

The use of immobilized enzymes during saccharification of lignocelluloses enables the continuous process of enzymatic hydrolysis and repeatable use of enzyme, resulting in reduced operational cost. Novel nano-biocarriers were developed by layer-by-layer deposition of carbon nanotube (CNT) on the foam structures, and their efficiency for enzyme immobilization was demonstrated with cellulase and β-glucosidase. A three-fold enhancement was achieved in the activity of cellulase immobilized on CNT coated polyurethane foam. In addition, both cellulase and β-glucosidase immobilized on the CNT-foam showed much better storage stability and operational stability than the ones immobilized on the commercial biocarrier (Celite), which is critical for a continuous operation. CNT coated monolith was also developed as a biocarrier, offering high surface area and geometric stability. These nano-biocarriers are promising candidates for the efficient saccharification of biomass and to reduce carbon footprint and cost of the equipment.