The bacteriostatic and bactericidal activities of 22 essential oils (anise, calamint, celery, coriander, cornmint, cumin, dill, fennel, Laser, laurel, lemon peel, lemon leaf, orange peel, oregano, parsley, rosemary, sage, savory, tarragon, thyme, wild thyme, and Ziziphora) from Turkish spice and citrus plants against seven bacteria (Aerobacter aerogenes, Bacillus subtilis, Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa, Staphylococcus albus, and Staphylococcus aureus) were evaluated.
The results showed that the essential oils tested varied in their antibacterial activity. Anise, celery, coriander, parsley, and sage were inactive or had little activity; while cornmint, cumin, laurel, lemon peel, orange, oregano, and Ziziphora were active against all tested bacteria to a variable extent. S. aureus and P. vulgaris were the most sensitive organisms, while P. aeruginosa was the most resistant except towards thyme oil. Fifteen essential oils had MBC lower than MIC and only seven were at about the same level. The results also showed that the bacteriostatic data obtained by agar diffusion and serial dilution methods were not always comparable; therefore, in testing the biostatic effects of essential oils it is advisable to carry out both techniques.