Abstract
Cellulases are essential in various industrial processes, particularly for converting cellulosic biomass into valuable biochemicals, contributing to sustainable and eco-friendly technologies. Despite their significance, cellulases; especially β-glucosidase (BGL), which catalyzes the final step in cellulose hydrolysis, face challenges such as low catalytic efficiency, narrow substrate specificity, and sensitivity to operational conditions, limiting large-scale application. Enhancing these enzymatic properties is vital to improving the economic and environmental performance of bioconversion processes. To address these issues, multiple enzyme engineering strategies have been explored. For example, in Aspergillus niger, heterologous expression using the Pcdna1 promoter from T. reesei led to a 13.9-fold increase in BGL activity and improved thermal stability. Advanced synthetic biology tools such as CRISPR-Cas9 further expand possibilities for targeted improvements. Additionally, omics approaches; genomics, transcriptomics, proteomics, and metabolomics offer comprehensive insights for more precise and rational engineering. Enzyme immobilization on nanoparticles also boosts BGL's stability, reusability, and industrial applicability. This review emphasizes the significance and limitations of these strategies in enhancing BGL's catalytic performance, thermal stability, and glucose tolerance. Moreover, it highlights BGL's broad industrial relevance in biofuel production, food and beverage processing, and pharmaceutical applications, underscoring its crucial role in promoting sustainable and economically feasible bioprocess technologies.