Özet:

The purpose of this study are to isolate Lactic Acid Bacteria (LAB), which have an antagonistic activity against Lactococcus garvieae, in the intestinal microflora of rainbow trouts and to reveal in vitro, the probable probiotic potential of the bacterial species, which were determined to have an antagonistic effect. For this aim LAB species were isolated from the intestinal flora of rainbow trouts using conventional culture methods. The antagonistic efficiencies of the obtained isolates against L. garvieae were determined with the agar well diffusion test. The hydrophobicity, pH and bile tolerance levels and antibiotic susceptibility profiles of the isolates, which were found to have antagonistic activity, were determined in the next stage. Genetic identification of the obtained candidate probiotic bacteria was performed with PCR method. A total of 47 isolates were obtained from the intestinal flora of the rainbow trout. Six of these isolates were determined to have antagonistic activity against L. garvieae. Further tests revealed that the isolates were hydrophobic, resistant to high bile and low pH conditions, and that all isolates were resistant to five different antibiotics. Following genetic identification, five of the isolates were identified as Lactobacillus acidophilus. One of the isolates was defined as Lactobacillus spp. With this study, possible probiotic bacteria were obtained, which can be used to control L. garvieae, widespread in our country's culture fish farming.

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