Nanobiotechnological enhancement of bioethanol production from potato peel waste using green-synthesized ZnO nanoparticles

The growing demand for sustainable energy and effective waste management has intensified interest in bioethanol production from agro-industrial residues. This study investigates the potential of potato peel waste (PPs) as an economical substrate for enhanced bioethanol production using a nanobiotechnological approach. Zinc oxide nanoparticles (ZnONPs) were green-synthesized using potato peel extract and characterized through SEM, EDX, and zeta analysis, confirming their nanoscale size, stability, and elemental composition. An alkali-thermophilic bacterial strain, Bacillus licheniformis (OQ740163), exhibiting both amylolytic and cellulolytic activities, was employed for biomass hydrolysis. The incorporation of ZnONPs significantly enhanced saccharification efficiency, yielding a maximum reducing sugar concentration of 9.58 g/L compared to 5.91 g/L without nanoparticles, representing a 61.96% increase. Subsequent fermentation using Saccharomyces cerevisiae K7 further demonstrated improved ethanol production, achieving a yield of 0.460 g/g glucose compared to 0.399 g/g in the control. The findings highlight the catalytic role of ZnONPs in enhancing both hydrolysis and fermentation processes. Overall, this study presents a sustainable and cost-effective strategy for converting potato peel waste into bioethanol, contributing to renewable energy production and circular bioeconomy development.