The inhibitory effect of some natural volatile oils on Cyanobacteria (Anabaena wisconsinense) and some Pathogenic Bacteria

Abstract

The main objective of this study was to test the inhibitory effect of clove oil (Syzygium aromaticum), peppermint oil (Mentha longifolia), basil oil (Ocimum basilicum) and castor oil (Ricinus communis) on the growth of cyanobacteria (Anabaena wisconsinense)as well as four pathogenic bacteria (Escherichia coli, Vibrio sp. Pseudemonas sp. and Aeromonas sp.). The algicidal activity of investigated volatile oils was tested at 3 concentrations of the crude oils (50, 100, 150 ppm) on the growth of Anabaena wisconsinense, and at 3 volumes (10, 20, 30 µl) on the growth rates of the tested species of pathogenic bacteria. Results showed that the investigated volatile oils have a strong antagonistic effect on Anabaena wisconsinense. Clove and peppermint oils were the highest inhibitory action against A. wisconsinense. Growth rates of all tested bacteria Also were inhibited with clove and peppermint oils while basil and castor oils had no effect against Pseudemonas sp. and Aeromonas sp. at any volumes. Anabaena wisconsinense and pathogenic bacteria were more sensitive to the allelopathic and antibacterial effect of clove and peppermint oils.