An engineered Aspergillus fumigatus GH3 β-glucosidase with higher glucose tolerance

β-glucosidases (3.2.1.21) are present in all domains of living organisms, and their importance in a number of essential biological processes and industrial applications has been highlighted. They are interesting for biomass conversion because b-glucans are the world’s largest source of biomass. For this reason, several fungal β-glucosidases have been investigated. The β-glucosidase gene of Aspergillus fumigatus, as well as its mutants D262E and W263F, were cloned and expressed in Pichia pastoris in this study. Their optimum temperature, pH, glucose tolerance, metal ion effect, and Vmax, km, and kcat were determined. The optimal temperature for recombinant β-glucosidase was 65 °C. For mutant D262E, there is an improvement in pH stability ranging from 4 to 6. As compared to the D262E mutant and recombinant β-glucosidase, mutant W263F showed a higher glucose tolerance and kcat.