Antibacterial potential of the essential oil from Sideritis montana L. (Lamiaceae)

The antibacterial potential of essential oil from Serbian Sideritis montana L. (Lamiaceae) on different bacteria was investigated. The essential oil was obtained from air dried aerial parts of the plant with 0.03% (w/w) yield by hydrodistillation for 4 h using a Clevenger-type apparatus. The essential oil analyses were performed simultaneously by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) systems. Dominant compounds class is sesquiterpene hydrocarbons. The main constituents of oil were germacrene D (37,9%) and trans-geraniol (26,1%). The antibacterial activity of the essential oil was tested towards 4 different bacteria, laboratory control strain obtained from the American Type Culture Collection (ATCC). Gram negative bacteria were represented by Escherichia coli ATCC 13706, Pseudomonas aeruginosa ATCC 27853, Salmonella enteritidis ATCC 13076 while researched Gram positive strain was Staphylococcus aureus ATCC 29213. Broth microdilution method was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Essential oil has been found to have antibacterial activity against all tested bacteria, with a MIC values ranging from 0.03 to 0.06 μl/ml and MBC values from 0.06 to 0.12 μl/ml. Reference antibiotic tetracycline was active in concentrations between 0.025 to 0.1 μg/ml. Essential oil from Serbian S. montana has high antibacterial potential which should be studied further.