Note: Inhibition of pathogenic bacteria by essential oils at different concentrations

The antimicrobial effect of 11 selected Turkish spice essential oils was investigated against seventeen pathogenic bacteria. The antimicrobial activity of the essential oils of six spices (cumin, fennel, laurel, mint, marjoram, oregano, pickling herb, sage, savory, thyme (black) and thyme) was tested at four concentrations (0.2, 0.4, 1 and 2%) on various microorganisms (E. aerogenes, E. coli, E. coli O157:H7, K. pneumoniae, P. vulgaris, S. enteritidis, S. gallinarum, S. typhimurium, S. aureus, Y. enterocolitica, A. hydrophila, C. xerosis, M. luteus, M. smegmatis, E. feacalis, P. aeruginosa and P. fluorescens). All preparations showed antibacterial activity against at least one or more bacteria. The inhibitory effect of the essential oils was evaluated through paper disc diffusion method. In general, the essential oils at 1 and 2% levels were effective. The most active essential oils were marjoram, thyme and oregano. According to the results, the studied essential oils potentially might be used as antibacterial agents to prevent the spoilage of food products, although further research is needed.