Antimicrobial activity of the essential oil of wild-growing Micromeria thymifolia (Scop.) Fritsch

The genus Micromeria Benth. (Lamiaceae, Nepetoideae) includes about 130 species, often aromatc. The essential oil and extracts of some Micromeria species have significant antioxidant, antibacterial and antifungal activities. Micromeria thymifolia is endemic species of the Balkan peninsula. It has been traditionally used in the Mediterranean area as condiment and medicinal plant. The aim of this study was to investigate antimicrobial properties of essential oil of wild Micromeria thymifolia against four Gram negative bacteria (Escherichia coli SY252, Pseudomonas aeruginosa ATCC27853, Salmonella enterica ATCC13076 and human patogen Burkholderia cepacia ATCC25416), four Gram positive bacteria (Enterococcus fecalis ATCC29212, Staphylococcus aureus ATCC25923, Bacillus subtilis ATCC6633, Listeria innocua ATCC33090) and two fungi strains (Candida albicans ATCC10231 and Saccharomyces cerevisiae ATCC9763). The MICs of M. thymifolia essential oil against tested bacteria and fungi was assessed using microtitre plate-based antimicrobial assay. MHB was used as growth media for bacteria, with exception of L. innocua when BHI was used, YPD was used for fungi. The results of our investigation showed that the essential oil of wild-growing M. thymifolia possess significant antimicrobial activity against all tested strains except the P. aeruginosa.