Cellulase enzymes for sustainable sugarcane waste management: a comprehensive review

This review assesses the role of cellulase enzymes in the sustainable management of sugarcane waste, focusing on bagasse, trash, and press mud as key lignocellulosic residues. It synthesizes recent experimental and industrial research to evaluate cellulase sources, enzyme systems (endoglucanase, exoglucanase, and β-glucosidase), and pretreatment techniques that impact hydrolysis efficiency. The review underscores that physicochemical pretreatments, such as dilute acid, alkali, steam explosion, and ionic liquids, greatly enhance cellulose accessibility, achieving glucose yields of 70-90% under optimal conditions. Fungal cellulases, particularly from Trichoderma reesei and Aspergillus species, outperform bacterial systems in the saccharification of sugarcane biomass, especially when used in synergistic enzyme cocktails. Key findings also reveal that enzyme immobilization and genetic engineering improve thermal stability, reusability, and catalytic efficiency, thereby lowering the overall processing costs. Furthermore, life cycle and techno-economic assessments show that enzymatic valorization of sugarcane waste significantly reduces greenhouse gas emissions and supports the production of high-value products, including bioethanol, biogas, organic acids, and biopolymers. Overall, this review establishes cellulase-based bioconversion as a technically viable and environmentally sustainable method for large-scale sugarcane waste utilization, while identifying enzyme cost, pretreatment severity, and scale-up challenges as major barriers to industrial application.