Antifungal activity of a food-grade dilution-stable microemulsion againstAspergillus niger

Abstract

Aims: To study the antifungal activities of a prepared food‐grade dilution‐stable microemulsion against Aspergillus niger. Methods and Results: Results from the antifungal activity on solid medium by agar dilution method showed that the microemulsion caused complete growth inhibition at 2000 ppm, and at 1000 ppm, showed 55% growth inhibition after 4 days of incubation and a delay of conidiation by 1 day compared with controls. Results from the antifungal activity in liquid medium by broth dilution method showed that the growth of A. niger was completely inhibited when a liquid medium containing 106 spores per ml was treated with 500 ppm of microemulsion, which was determined by minimum fungicidal concentration. Study of fungicidal kinetics showed that more than 99% of viable spores were killed within 15 min. These antifungal activities were confirmed by scanning electron microscopy, light microscopy and increased Ca+2, K+ and Mg+2 leakages. Conclusions: The results suggest that the prepared microemulsions are effective antifungal systems with excellent growth inhibition and sporicidal activities, and indicate that their antifungal activity may be to the result of the disruption and dysfunction of A. niger cell walls and biological membranes. Significance and Impact of the Study: This study suggests the potential use of food‐grade dilution‐stable microemulsions for antifungal use in the food and pharmaceutical industries.

Characterization and antimicrobial activity of a pharmaceutical microemulsion

“…On the other hand, the microemulsion killed over 99% A. niger and P. expansum spores and 99.9% C. albicans cells rapidly within 2 min and a complete loss of viability was obtained in 5 min. This is comparable to our previous work (Zhang et al, 2008c), which has proved that the GML-loaded microemulsions are effective antifungal systems with sporicidal activities against A. niger.…”

“…However, there are very few literatures concerning the antifungal mechanism of microemulsions. Our previous work (Zhang et al, 2008c) has evaluated the antifungal activities of a prepared GML-loaded microemulsion against A. niger. The excellent growth inhibition and sporicidal activities of the microemulsion were confirmed by the observation of scanning electron microscopy, light microscopy and increased Ca 2+ , K + and Mg 2+ leakages, indicating the disruption and dysfunction of fungal cell walls and biological membranes.…”

Influence of monoacylglycerols on growth inhibition of micromycetes in vitro and on bread

“…Inhibition of growth of this species was observed using 164 mg/L monolaurin and spore inhibition using 300 mg/L monolaurin. According Zhang et al [25,26] microemulsions containing monolaurin can modify the morphology of A. niger. The microemulsions inhibited growth and conidiation both of aspergilli and penicillia.…”

Influence of sunflower oil based nanoemulsion (AUSN-4) on the shelf life and quality of Indo-Pacific king mackerel (Scomberomorus guttatus) steaks stored at 20 °C

“…Numerous reports suggest their adverse effect on the structure and function on bacteria (Bortoleto, DeOliveira, Ruller, Arni, & Ward, 1998;Friberg, 1984;Jones, Song, Kaszuba, & Reboiras, 1997), fungi (Hamouda et al, 1999;Myc et al, 2001;Zhang et al, 2008) and viruses (Chepurnov et al, 2003;Donovan et al, 2000) by destabilizing the organism's lipid envelope (Baker, Hamouda, Shih, & Andrzej, 2003).…”