Molecular Identification of Lactobacillus acidophilus as a probiotic potential from traditional doogh samples and evaluation of their antimicrobial activity against some pathogenic bacteria.

Abstract

Aims: Lactobacillus acidophilus is a potentially probiotic bacteria which added to food products as a probiotic starters to create taste and capabilities such as health-giving and so by this path they enter the food chain of humans. Furthermore, these microorganisms can be identified and isolate in traditional products. In this study tried to identify and isolate the Lactobacillus acidophilus in traditional Doogh samples from Tabriz region in the northwest of Iran. Material and methods: The identification of these microorganisms was performed using biochemical tests and molecular method by PCR. Randomly 42 samples were collected from the area, eventually 15 isolates were identified as Lactobacillus acidophilus. To study the antimicrobial activity of cell-free supernatants of isolates against Staphylococcus aureus (ATCC 25923), Shigella dysenteriae and Escherchia coli (ATCC 25922) well diffusion method was used and the inhibitory effect on the growth of pathogenic bacteria was established. Results and conclusion: Isolated isolates showed different inhibitory effects so that the highest antimicrobial effect was observed against Shigella dysentery. The results of this study suggest that the isolates isolated from traditional doogh that inhibit the growth of Gram-positive and Gram-negative can be used as new industrial starters.