Isolation and identification of probiotic bacteria in milk and milk products

Nowadays, the attention increased to foods containing probiotics such as milk, cheese and kefir and probiotic strains of them. In this study, totally 209 strains of bacteria were isolated from 9 cheese, 1 kefir, 1 pasteurized milk, 1 raw milk and 1 suck products. These isolates were tested for antimicrobial activity and determined 73 isolates having antimicrobial activity. The identification of these 73 isolates were performed with morphologic, biochemical tests and also riboprinter system. According to riboprinter system result, 58 Enterococcus faecium, 1 Enterococcus faecalis, 1 Enterococcus durans, 1 Lactobacillus fermentum, 4 Lactobacillus reuteri, 1 Lactobacillus paracasei spp. paracasei, 7 Pediococcus acidilactici isolates were determined. Riboprinter system and biochemical test results were same for 53 isolates but no other 20 isolates. One of the criterions used for choice of bacteria having probiotic characteric is able to growth in acidic environment. Regarding these results, 68 isolates grew in pH 3, 60 isolates in pH 2, 39 isoltes pH 1 of totally 73 isolates. 13 isolates kept livelines in pH 2 during 24 hours. In addition, 22 isolates of 73 have able to grow in % 0,4 phenol. 11 isolates chosen were found as resist against Ciprofloxacin, Penicillin-G, Gentamycin, Netilmycin Sulphate and Cefaclor; 7 isolates were found as sensitive against to all of the antibiotics tested. As a result of all performed tests, amount of lactic acid, proteolitic activity and hydrogen peroxide produced by 41 isolates were found between 0,18-18,41 mg/ml, 0,23?2,04 mg/ml, 0,29?2,50 µg/ml respectively.Keywords: Probiotic Bacteria, Milk and Milk Products, Isolation, Antimicrobial Activity