In vitro investigation the effect of fennel essential oils on Yersinia ruckeri to be fish pathogen

In this study, with thinking it may be an alternative to commercial antibiotics of natural product without additives, inhibitor effects of fennel (Foeniculum vulgare Miller) essential oil to Yersinia ruckeri, etiologic agent of Enteric Red Mouth Disease, were investigated in vitro. The chemical components of fennel essential oil (F. vulgare) were determined by GC and GC-MS analysis and the main component was found to be benzene (67.99%). The antimicrobial effect of F. vulgare was determined by disk diffusion method and inhibition zones were measured. For this purpose, two experimental concentrations of F. vulgare (5 and 10 μL) were applied and antibiotics (Streptomycin and Tetracycline) as the control group used. In application of 5 μL / disc of F. vulgare, the inhibition zone of the Y. ruckeri was 10.52 ± 1.04 mm; was 13,10 ± 1,67 mm in the concentration treated 10 μL / disc. Streptomycin and Tetracycline had strong antibacterial activity with 21,05 ± 3,23 and 27,72 ± 2,02 mm zones, respectively. When compared to control group two concentrations tested, a weaker inhibition zone was observed. The data obtained indicated that F. vulgare essential oil had an antibacterial effect to Y. ruckeri.