| Abstract: | The antifungal activity of two essential oil components (citral and menthol) towards Aspergillus niger and Rhizopus stolonifer was studied in shake culture. The activity was high with lower inoculum density (measured in terms of number of spores ml?1), and it decreased as the inoculum density increased. Citral at 200 μg ml?1 and menthol at 400 μg mh?1 were lethal to the spores of A. niger and R. stolonifer, respectively, after a 48-h treatment. At lower concentrations both the compounds were only fungistatic: the growth of the fungi resumed after an initial delay or upon transfer to fresh medium. Periodic estimations of the essential oil components by gas-liquid chromatography showed a continuous decrease in their concentrations in the culture medium, indicating their removal tending to detoxification. The difference in the activity of the two compounds was related to the capacity of the fungi to detoxify the compounds. |
