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The 11th International Mediterranean Symposium on Medicinal and Aromatic Plants, Rimini, Italy, 6 - 08 May 2025, pp.108, (Summary Text)
This study aimed to evaluate the efficacy of selected essential oils against five bacterial and two fungal strains using thevapour-phase diffusion method. Fifteen essential oils were tested in their pure and vapour forms. Carvacrol, known for its broad-spectrum antibacterial and anticandidal activity, was used a standard natural antimicrobial agent. The chemical composition of essential oils was analyzed using a SHIMADZU GC-2010 Plus GC/MS system. CP-Sil 5CB column was used. Mass spectra were identified using the Wiley and Adams-LIBR(TP) databases. The RRI was obtained by applying an oil sample with a C9-C40 linear hydrocarbons mixture [1, 2]. Essential oils and major consituents were tested against Staphylococcus aureus ATCC 6538, S. epidermidis ATCC 12228, Escherichia coli NRRL B-3008, Pseudomonas aeruginosa ATCC 9027, Serratia marcescens NRRL B-2544, Candida albicans ATCC 90028 and C. parapsilosis ATCC 22019. Essential oils (10 μL) were applied to sterile filter paper discs placed on Petri dish lids. Plates were incubated at 37°C for 24 hours [3, 4]. For anticandidal evaluation, essential oils were tested on PDA plates for 24 and 48 hours [5]. After incubation period pigment production of S. aureus significantly inhibited by O. basilicum and C. sativum EOs. C. sativum exhibited strong efficacy against S. aureus (10 μL-28 mm ) and P. aeruginosa (10 μL- 21 mm ). Furthermore, O. basilicum was particularly effective against E. coli. The most efficient oils against C. albicans were E. caryophyllus (5μL- 20 mm ) M. piperita (5μL- 33 mm ) and C. sativum (5μL- 13 mm According to bioimagings several structural damages were demonstrated on cell membrane, protoplasm and nuclei. This study shows that essential oils in vapour phase have significant antimicrobial effects, especially against Candida species. These findings highlight their potential a natural antimicrobials with broad-spectrum activity against bacterial and fungal pathogens. In this context, the vapour phase of essential oils plays a key role in reducing microbial load on surfaces and in the air, with significant potential to prevent contamination.
Key Words: Vapour phase, essential oils, SEM/TEM analysis, pathogenic microorganisms, mechanism of action
Acknowledgements: This work has been supported by Anadolu University Scientific Research Projects Coordination Unit under grant number YTT-2024-2568.
References [1] McLafferty, F. W., & Stauffer, D. B. (1989). The Wiley/NBS registry of mass spectral data (Vol. 1). New York: Wiley.
[2]
Boelens, M. (1999). The complete database of essential oils, Boelens Aroma chemical information service. The Netherlands.
[3] Elgayyar, M., Draughon, F. A., Golden, D. A., & Mount, J. R. (2001). Antimicrobial activity of essential oils from plants against selected pathogenic and saprophytic microorganisms. Journal of food protection, 64(7), 1019-1024 https://doi.org/10.4315/0362-028x-64.7.1019
[4] Inouye, S., Uchida, K., Maruyama, N., Yamaguchi, H., & Abe, S. (2006). A novel method to estimate the contribution of the vapor activity of essential oils in agar diffusion assay. Nihon Ishinkin Gakkai zasshi = Japanese journal of medical mycology, 47(2), 91–98. https://doi.org/10.3314/jjmm.47.91
[5] Guynot, M. E., Ramos, A. J., Seto, L., Purroy, P., Sanchis, V., & Marin, S. (2003). Antifungal activity of volatile compounds generated by essential oils against fungi commonly causing deterioration of bakery products. Journal of Applied Microbiology, 94(5), 893-899. https://doi.org/10.1046/j.1365-2672.2003.01927.x