Abstract

SCREENING OF FUNGI ON SORGHUM BICOLOR AND ANTIFUNGAL ACTIVITY OF ESSENTIAL OILS BY AGAR WELL DIFFUSION METHOD

Prathibha K. Y., Aathiya Vanekar, Geethanjali R. and Marhoob Banu*

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Abstract

The present study was conducted with the main purpose to assess antifungal activity of five essential oils viz., Camphor oil, Cinnamon oil, Clove oil, Eucalyptus oil and Rose oil at concentrations of 20%, 40%, 60%, 80% and 100% respectively on Aspergillus flavus, by agar well diffusion method. Screening of fungi on Sorghum bicolor was done by standard blotting technique and the fungi studied were Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Chaetomium globosum and Mucor sp.,. Potato dextrose agar was prepared and well grown colony of Aspergillus flavus was inoculated. Pure culture of Aspergillus flavus was obtained by subculturing the previous culture and incubated at 27 ± 2 °C for 48 h. Aspergillus flavus was suspended in sterile water and adjusted to a standard inoculum size to 1-2 x 106 CFU/mL. Seven wells of five millimetres diameter were punched in the agar and filled with 20 μL (2 mg) of different concentrations of essential oils individually along with 20 μL of itraconazole solution. 20 μL of 50% ethanol was added as control. The treated plates with essential oils, reference standard and control were incubated at 27 ± 2 °C for 7 days. After incubation the treated plates were observed for zone of inhibition around wells and also for complete inhibition. It was observed that few essential oils were effective in completely inhibiting the fungal growth while some oils showed zone of inhibition. Zone of inhibition was measured in millimetres (mm) and recorded.

Keywords: Antifungal activity, Agar well diffusion method, Itraconazole, Sorghum bicolor, Aspergillus flavus, Potato dextrose agar.