Effect of nickel oxide nanoparticles on bioethanol production: Process optimization, kinetic and metabolic studies

[Display omitted] •Nickel oxide nanoparticles inclusion improved ethanol concentration up to 19 %.•Optimum conditions for NiO NPs supplemented fermentation were established.•Three kinetic models were used to describe batch fermentation with NiO NPs inclusion.•NiO NPs enhanced total cell protein and carbohydrate accumulation.•Presence of NiO NPs substantially reduced volatile compounds concentration. The present study optimized ethanol yield using nickel oxide (NiO) nanoparticles (NPs) as a biocatalyst. Additionally, Saccharomyces cerevisiae BY4743 cell growth and the bioethanol production kinetics were assessed. The Response Surface Methodology (RSM) model showed a coefficient of determination (R2) value of 0.93. The optimized process gave a biomass concentration and ethanol yield of 2.04 g/L and 0.26 g/g (1.03 and 1.19-fold increment compared to the control experiment), respectively. The process kinetic data showed that the inclusion of NiO NPs improved the affinity of S. cerevisiae BY4743 to glucose consumption, carbohydrate and protein accumulation. A significant reduction in volatile fatty acid (VFA) was observed in the presence of NiO NPs. The application of nano biocatalyst in simultaneous saccharification and fermentation of potato peel waste, meaningfully enhanced bioethanol production (>65 %). The study provided major insights into the use of NiO NPs to enhance the bioprocess of ethanol production.