The Inhibitory Effects ofCurcuma longaL. Essential Oil and Curcumin onAspergillus flavusLink Growth and Morphology

Abstract

The essential oil fromCurcuma longaL. was analysed by GC/MS. The major components of the oil were ar-turmerone (33.2%),α-turmerone (23.5%) andβ-turmerone (22.7%). The antifungal activities of the oil were studied with regard toAspergillus flavusgrowth inhibition and altered morphology, as preliminary studies indicated that the essential oil fromC. longainhibitedAspergillus flavusLink aflatoxin production. The concentration of essential oil in the culture media ranged from 0.01% to 5.0% v/v, and the concentration of curcumin was 0.01–0.5% v/v. The effects on sporulation, spore viability, and fungal morphology were determined. The essential oil exhibited stronger antifungal activity than curcumin onA. flavus. The essential oil reduced the fungal growth in a concentration-dependent manner.A. flavusgrowth rate was reduced byC. longaessential oil at 0.10%, and this inhibition effect was more efficient in concentrations above 0.50%. Germination and sporulation were 100% inhibited in 0.5% oil. Scanning electron microscopy (SEM) ofA. flavusexposed to oil showed damage to hyphae membranes and conidiophores. Because the fungus is a plant pathogen and aflatoxin producer,C. longaessential oil may be used in the management of host plants.