Antibacterial Effects of Ocimum Sanctum L Leaves, Flowers and Shoots against Bacillus spp from Soil

Abstract

In this study, the antibacterial activity of various organic solvent extracts of Ocimum sanctum L leaves, flowers and shoots was determined in vitro using agar diffusion method and MIC tested against the isolated soil bacteria. The identified bacteria were Paenibacillussp. L32, Paenibacillussp. BF38, Bacillus megaterium, Terribacillussp. 3LF, Bacillus simplex and Bacillus cereus. Various organic extracts of Ocimum sanctum L revealed a good antibacterial activity against about all bacteria. Results showed that the best extract was methanol because highest inhibition zone were obtained by this extract and all studied bacteria were inhibited. At a concentration of 500 µg/disc, the highest microbial inhibition was found 19.2±.76 mm against Bacillus simplex for methanol extract, 15.7±0.58 mm on Terribacillus sp. 3LF for ethanol extract of flower, 14.0±2.0 mm on Terribacillus sp. 3LF for ethanol extract of leaves, 13.34±0.58 mm on Bacillus megaterium for n-hexane extract and 11.7±0.6 mm on Terribacillus sp. 3LF for chloroform extract, respectively and MIC (64, 128, 256 and 512 µg/ml, respectively). Most of the cases, antibacterial activity with commercial antibiotics such as amoxicillin and erythromycin, organic extracts exhibited similar or higher antibacterial activity than standard drug. The results of this study suggest that the organic extracts of Ocimum sanctum L leaves can be a source of natural antimicrobial agents with potential applications.