Antimicrobial Effects of Several Essential Oil from Aromatic Plants

Abstract

Essential oils (EOs) have been long recognized for their antibacterial, antifungal, antiviral, insecticidal and antioxidant properties. The present research aimed to study the antimicrobial effects of some volatile oils from aromatic plants (sweet basil and dill) against several microorganisms, namely Bacillus subtilis, Alternaria alternata and Penicillium expansum. The oils have been extracted through distillation procedures and the antimicrobial action of the oils was assessed through the disc diffusion method. The best effect against the Bacillus subtilis strain has occurred when the essential oil of dill was undiluted. Regarding the the Alternaria species, it was noted that dill volatile oil has acted in an efficient way only undiluted. As the oil's concentration decreased, the strain becomed resistant. The sweet basil oil has proven to be highly effective when acting against the Bacillus strain. By volatilization, the sweet basil oil produced a strong antimicrobial effect, even in control disc, in which it was noticed a small development of colonies comparing with the dill oil. The results indicated that the sweet basil essential oil exerted an antimicrobial effect both against the tested bacteria and moulds, while the dill oil had a great inhibitory action on Bacillus subtilis and Alternaria alternata, but was less efficient against Penicillium expansum.