In vitro bioactive effects of lactic acid bacteria isolated from various sources evaluation of features

In this thesis, it was aimed to evaluate the in vitro bioactive properties of lactic acid bacteria isolated from different sources (horse feces, soil, chicken feces, fish intestine and fish intestinal content). 91 lactic acid bacteria were isolated from the samples: 31 from horse feces, 7 from soil, 3 from chicken feces, 23 from fish intestinal system and 27 from fish intestines. Among these, 6 isolates were selected to examine their characteristics, taking into account gram staining, catalase and cell morphologies. Molecular identification of the 6 selected isolates was made by 16S rRNA gene region sequence analysis method. According to this method, isolates ATD02-03, ATD04-01, TOP01-01, BI02-03, BB03-10 were identified as P. acidilactici, and isolate ATD05-02 was identified as L. plantarum. Identified isolates were registered with the National Center for Biotechnology Information (NCBI). In the test to determine bacteriocin production properties, the cell-free supernatant showed an inhibitory effect on all indicator microorganisms except Aeromonas hydrophila. In the cross-line method test, ATD05-02 isolate showed the highest activity against Lactococcus garvieae. ATD 05-02, TOP 01-01, BI 02-03, BB 03-10 isolates were determined to have protease enzyme activity. Keywords: Pediococcus, Lactiplantibacillus, bacteriocin, 16S rRNA, enzyme activity