Determination of probiotic and some technological properties of lactic acid bacteria isolated from cheeses sold in the Kilis region, Turkey

Abstract

Aims: The purpose of this study is to evaluate technological properties and probiotics potential of lactic acid bacteria (LAB) isolated from 15 raw milk Turkish Beyaz fresh cheese made in the Kilis region, Turkey.Methods and Results: 287 colonies from 15 cheese samples were selected and 91 of them were analyzed as Gram-positive and catalase-negative. 19 strains of 91 colonies were accepted as potential probiotics since they stayed alive in pH 3.5 and 0.3% bile salt. They were identified as Lactobacillus sp. (11 strains), Leuconostoc sp. (3 strains), Streptococcus sp. (2 strains), Lactococcus sp. (2 strains), and Enterococcus sp. (1 strain) by biochemical tests and API test kit. It was determined that 19 strains with high acidification rate, 15 strains demonstrated weak proteolytic activity, 3 ones moderate, and 1 strong proteolytic activity. It was determined that 1 of the strains were resistant to chloramphenicol, 2 to tetracycline, and 6 to vancomycin. No strains resistant to penicillin and erythromycin could be detected. In the artificial gastric juice resistance test, although no viability was detected at pH 2.0. But it was determined that the viability values varied between 89.49-111.79% at pH 3.0. Also, these strains showed growth at bile salt. According to plasmid profiles of strains, 13 of 19 potential probiotic strains were determined to have plasmid DNA in the range of 1-5, while other strains were determined to not have plasmid DNA. The molecular sizes of the plasmid DNA of the isolated strains ranged from 2-16 kb.Conclusions: In the research, it was determined that LABs isolated from Turkish white fresh cheese produced in Kilis have probiotic potential and can be used as starters in various fermented foods.Significance and Impact of the Study: According to the results obtained, it was concluded that some strains can be used as probiotic starter culture in cheese production and others can be used for ripening of cheese.