β-Glucosidase coating on polymer nanofibers for improved cellulosic ethanol production

β-Glucosidase (βG) can relieve the product inhibition of cellobiose in the cellulosic ethanol production by converting cellobiose into glucose. For the potential recycled uses, βG was immobilized and stabilized in the form of enzyme coating on polymer nanofibers. The βG coating (EC-βG) was fabricated by crosslinking additional βG molecules onto covalently attached βG molecules (CA-βG) via glutaraldehyde treatment. The initial activity of EC-βG was 36 times higher than that of CA-βG. After 20 days of incubation under shaking, CA-βG and EC-βG retained 33 and 91% of each initial activity, respectively. Magnetic nanofibers were also used for easy recovery and recycled uses of βG coating. It is anticipated that the recycled uses of highly active and stable βG coating can improve the economics of cellulosic ethanol production so long as economical materials are employed as a host of enzyme immobilization.