Abstract: The sample of the Mentha haplocalyx Briq. essential oil was analyzed by GC-MS. From 21 compounds representing the oils, Isophorone(41.22%), β-Caryophyllene(10.01%), Spathulenol(2.89%), β-Pinene(1.45%) and Eucalyptole(1.13%) appeared as the main components. The screening of antimicrobial activity of the essential oil was evaluated using agar diffusion and broth microdilution methods. Tests showed that the oil presented the biggest inhibition zones in the two strains of Bacillus subtilis and Proteus vulgaris. The MICs of the oil against the tested microorganisms ranged from 5.00% to 0.039%. Of the 8 microorganisms, Proteus vulgaris presented the lowest MIC(0.625%) and MBC(1.25%) values. Results presented here may suggest that the essential oil of Mentha haplocalyx Briq. possesses antimicrobial properties, and therefore is a potential source of antimicrobial ingredients for food and pharmaceutical industry.

Key words: Mentha haplocalyx Briq., essential oil, antimicrobial activity