Isolation of Bacillus subtilis and its antagonistic effects against dermatophytic fungi Microsporum fulvum and Trichophyton spp.

Among 40 bacterial isolates, a potent bacterium Bacillus subtilis-1 showed strong antifungal activity against dermatophytes. It inhibited the growth of fungi Trichophyton spp. and Microsporum fulvum upto 14 and 16 mm inhibition zone by spot inoculation method and 22 and 24 mm inhibition in well agar diffusion method, respectively. Among the 4 test media, maximum growth and antibiotic production was found in trypticase soy broth medium (TSB medium) and the optimal physiological conditions were found as 37°C temperature, pH 7 and 48 hour for maximum growth and antibiotic production. The minimum inhibitory concentration (MIC) of antifungal substance was noticed as 35 μl/ml and 45 μl/ml against test fungi Trichophyton spp. and Microsporum fulvum, respectively. Therefore, chemical characterization of its bioactive principle is required.