Chemical Composition and Antimicrobial Activity of Cinnamon, Thyme, Oregano and Clove Essential Oils Against Plant Pathogenic Bacteria

Essential oils are volatile substances from plants and many of them have antimicrobial activity. For that reason, they have become known as a useful alternative to chemical preservatives and pesticides. In this study, we tested essential oils of four aromatic plants. Cinnamon (Cinnamomum zeylanicum), thyme (Thymus vulgaris), oregano (Origanum vulgare) and clove (Syzygium aromaticum) essential oils were investigated for their composition and antimicrobial effect against plant pathogenic bacteria (Pectobacterium spp. and Pseudomonas spp.). Both are commonly associated with diseased fruit trees in orchards and gardens. The chemical composition of the tested essential oils was identified by gas chromatography coupled with mass spectrometry. The cinnamon essential oil was most effective form tested oil. The experimental results indicated that the wild strains of tested bacteria are more resistant to essential oils than commonly used laboratory strains. In conclusion, certain essential oils could be used for the control of postharvest bacterial pathogens. The findings of the present study suggest that the essential oils have a potential to be used as antimicrobial agents