susceptibility of microorganisms to myrtus communis l. essential oil and its chemical composition

the antimicrobial effects of essential oil isolated from myrtus communis l. against es-cherichia coli, staphylococcus aureus, streptococcus faecalis, pseudomonas aeruginosa, klebsiella pneumoniaee, bacillus subtilis, bacillus licheniformis, candida albicans and sac-charomyces cerevisiae were studied. the disc diffusion method was used to evaluate the zone of microbial growth inhibition at various concentrations of the oil. the minimal in-hibitory concentration (mic) and minimal bactericidal concentration (mbc) of the oil were determined. the oil was found to have an antimicrobial effect. kinetics of microbial destruction exhibited that the oil could kill microorganisms within 45 minutes of expo-sure. gc and gc/ms analysis of the oil revealed 32 components. the major components were α-pinene (29.4%), limonene (21.2%), 1,8-cineole (18%), linalool (10.6%), linalyl acetate (4.6%) and α-terpineole (3.1%). the high monoterpenes hydrocarbons such as α-pinene and limonene seem to contribute to the strong antimicrobial activity of myrtus communis l. further research on antimicrobial effects of essential oils with a view to sub-stituting the common chemical compounds is promising.