Comparison of traditional and commercial kefir microorganism compositions and inhibitory effects on certain pathogens

Abstract

The aim of this study was to compare traditional and commercial kefir products and their microbiological compositions along with their inhibitory activities against various pathogens. Different media and inhibitory conditions were used for identification of microbiological groups. Each microbiological group was subjected to gram and fluorescence staining. Biochemical identification was performed according to gram staining. Vitek 2 Compact system was used for biochemical identification. Identification cards; Gram-negative (GN), Gram-positive (GP), Anaerobe and Corynebacterium (ANC), Neisseria-Haemophilus (NH), Yeas-mold (YM) were selected according to gram staining. Bruker MS (16 s rRNA) was used for microorganism identification. The inhibitory effect onsome pathogens were examined. A diverse spectrum of bacterial genera were identified in kefir samples including: Lactobacillus (six species), Lactococcus (one species), Saccharomyces (one species) Streptococcus (one species), Bifidobacterium (two species). While traditional kefir had a greater inhibitory effect on Enterobacter cloacae and Escherichia coli pathogens than commercial kefir, commercial kefir had a greater inhibitory effect on Enterococcus faecalis pathogen than traditional kefir. In general, traditional kefir had most effective inhibitory effect on pathogens.