Inhibitory Effect of Helichrysum arenarium Essential Oil on the Growth of Food Contaminated Microorganisms

Abstract

The aim of this study was to determine the antimicrobial effect of Helichrysum arenarium L. essential oil in “in-vitro” condition on the growth of seven microbial species including Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Saccharomyces cereviciae, Candida albicans, Aspergillus flavus and Aspergillus parasiticus using micro-dilution method. The minimum inhibitory concentration (MIC) and minimum bactericidal or fungicidal concentration (MBC, MFC) were determined for the essential oil at ten concentrations. Finally, the sensitivity of tested microbes to essential oil of H. arenarium was investigated. Results showed that Bacillus subtilis (MIC = 781.25 and MBC = 6250 µg/ml) was more resistance than the two other bacterial species. Among the two yeasts tested, Saccharomyces cereviciae (MIC = 97.65 and MFC = 781.25 µg/ml) was more sensitive than Candida albicans (MIC= 195.31 and MFC= 3125 µg/ml) while among the fungal species, growth of Aspergillus parasiticus inhibited at lower concentration of the essential oil rather than Aspergillus flavus. In liquid medium (Mullerhinton broth), H. arenarium L. essential oil exhibited the same MIC value against both fungal strains (48.82 µg/ml), while in solid medium (Mullerhinton agar) different activity was observed against A. flavus and A. parasiticus with MFC values of 6250 and 390.625 µg/ml, respectively. Results of the present study indicates that H. arenarium L. essential oil has significant (P < 0.05) antimicrobial activity, which strengthen the potential use of these substances as antimicrobial in the future.