Investigation of essentials oils with antimicrobial effect against some pathogens

Epidemics due to infections in aquaculture, which is one of the developing sectors in our country due to its importance in human consumption, cause serious problems. Antibiotics have been used for many years in the fight against these diseases, but their excessive and frequent use has created many handicaps. For this reason, more natural and easier to apply herbal products have been used recently. In this thesis, the antibacterial activities of rosemary, lavender, laurel and eucalyptus plants were revealed by determining disk diffusion and MIC concentrations on Vagococcos salmoninarum, Yersinia ruckeri, Lactococcus garvieae, Aeromonas sobria and Vibrio anguillarum bacteria. Major components of essential oils; 1.8-Cineole (% 21.21), 3-Carene (% 17.42), Camphor (% 13.63) for rosemary; for laurel, α-Pinene (% 11.05), Eucalyptol (% 10.06), Cis-sabinene (% 18.03); for lavender, Linalyl acetate (% 34.33), Linalool (% 26.94), Camphor (% 5.18); for eucalyptus, Eucalyptol (% 82.15), α-Pinene (% 6.25), β-Pinene (% 1.60). Disk diffusion results were found to be in the range of 12-28 mm for all essential oils, and bactericidal effect was determined by inhibiting the growth of A. sobria and Y. ruckeri to a great extent (24-28 mm inhibition zone diameter). MIC values show that all essential oils have antimicrobial effect at concentrations of 100, 50, 25, 12.5 µL. In this study, the antibacterial activity of essential oils obtained from selected plants was determined, and the therapeutic activity on pathogens that cause important diseases in our sector was determined in vitro. Although it was seen that essential oils provide strong antibacterial activity on all pathogens, more comprehensive studies are needed for an effective treatment.