Effect of nickel oxide nanoparticles on bioethanol production by Pichia kudriavzveii IFM 53048 using banana peel waste substrate

Abstract

ABSTRACT The use of nanomaterials in bioethanol production is promising and on the increase. In this report, the effect of nickel oxide nanoparticles (NiO NPs) on bioethanol production in the presence of a novel yeast strain, Pichia kudriavzveii IFM 53048 isolated from banana wastes was investigated. The hot percolation method was employed for the green synthesis of NiO NPs. The logistic and modified Gompertz kinetic models employed in this study showed a 0.99 coefficient of determination (R2) on cell growth, and substrate utilization on the initial rate data plot which indicate that these model were best suited for bioethanol production studies. As a result, 99.95% of the substrate was utilized to give 0.23 g/L/h−1 bioethanol productivity, and 51.28% fermentation efficiency, respectively. At 0.01 wt% of NiO NPs, maximum production was achieved with 0.27 g/g bioethanol yield. Meanwhile, 0.78 h−1 maximum specific growth rate (µmax) of the microorganism, 3.77 g/L bioethanol concentration (Pm), 0.49 g/L/h production rate (rp.m), and 2.43 h production lag time (tL) were obtained when 0.01 wt% of NiO NPs were used during the bioethanol production process. However, a decrease in bioethanol concentrations occurred at ≥0.02 wt% of NiO NPs. The incorporation of NiO NPs in the simultaneous saccharification and fermentation (SSF) process improved the production of bioethanol by 1.90 fold using banana peel wastes as substrate. These revealed NiO NPs could serve as a suitable biocatalyst in the green production of bioethanol from banana peel waste materials.