The impact of fullerenol nanoparticles on the growth of toxigenic Aspergillus flavus and aflatoxins production in vitro and in corn flour

Antifungal and antimycotoxigenic activity of fullerenol nanoparticles (FNPs) were investigated on Aspergillus flavus growth isolated from a real food sample and aflatoxins (AFs) (AFB(1) and AFB(2) ) production. The final FNPs concentrations in in vitro and in commercial corn flour after the stationary incubation period of 7 and 14 days were in the range 0.16-80 mu g/mL and 0.16-80 mu g/g, respectively. Nanocharacterization of FNPs revealed an average size of 5-20 nm and a zeta potential of -35 mV. The highest degree of A. flavus mycelium growth inhibition (28%) after 7 days was observed for applied FNP concentration of 8.0 mu g/mL, while after 14 days FNP concentration of 0.32 mu g/mL led to the maximal inhibition of A. flavus mycelium growth (36%). Spearman's correlations analysis revealed a strong positive correlation between AFB(1) and AFB(2) concentrations in YES broth after 7 (R = 0.994, p < 0.05) and 14 days (R = 0.976), as well as between AFs concentrations and A. flavus mycelium mass after 7 (R = 0.786 for AFB(1) and R = 0.766 for AFB(2) ) and 14 days (R = 0.810 for AFB(1) and R = 0.833 for AFB(2) ). Paired samples t-test showed the existence of a statistically significant difference (p < 0.05) between the produced AFs concentrations after the incubation of 7 and 14 days. Regarding the artificially inoculated corn flour the lower applied FNP concentrations (0.16-0.8 mu g/g) achieved a reduction of AFB(1) up to 42% and 60% after 7 and 14 days, respectively.