Cellulases and hemicellulases in lignocellulose degradation: A comparative analysis of wild-type and recombinant...

The global transition toward sustainable bioprocesses and circular bioeconomy models has intensified interest in the efficient valorization of lignocellulosic biomass as a renewable feedstock. Enzymatic depolymerization of lignocellulose represents a critical step in the conversion of plant biomass into value-added chemicals and fuels. Microorganisms have evolved complex and synergistic enzyme consortia capable of degrading cellulose, hemicellulose, and lignin. However, their industrial application is often constrained by low yields, limited stability, and suboptimal catalytic efficiency. Recent advances in recombinant DNA technologies have enabled enhanced enzyme production and facilitated large-scale application. This review provides an overview of enzymes involved in lignocellulose degradation, including cellulases, and hemicellulases derived from wild-type microorganisms and recombinant expression systems. Natural and recombinantly produced enzymes are compared in terms of catalytic mechanisms, substrate specificity, expression platforms, and process performance. Particular emphasis is placed on recombinant strategies employed to enhance enzyme activity and stability. In addition to summarizing current progress, this article highlights key challenges hindering efficient enzymatic pre-treatment and outlines future research directions towards the development of robust, cost-effective, and environmentally sustainable enzyme systems for advanced lignocellulosic biorefineries.