isolation and identification of lactic acid bacteria with probiotic potential from traditional yogurt in Varamin province.
Subject Areas : microbiologyسحر هنرمند جهرمی 1 , fahimeh baghbani-arani 2 , Fatemeh Yaghoubi 3
1 - گروه میکروبیولوژی، دانشکده علوم زیستی، واحد ورامین-پیشوا، دانشگاه آزاد اسلامی، پیشوا، ایران
2 - Department of Genetics and Biotechnology, School of Biological Science, Varamin-Pishva Branch, Islamic Azad University, Varamin, Iran.
3 - Department of micobiology, Faculty of Biological sciences, Azad University Varamin Pishva branch, Varamin Iran.
Keywords: Lactic acid bacteria, Yogurt, Probiotic. Varamin,
Abstract :
Using probiotics such as Lactic Acid Bacteria (LAB) to produce valuable food is a universally accepted trend. Dairy products made from locally produced raw milk with different inherent characteristics make up an important part of the daily diet. This makes dairy a rich source of LAB screening. The aim of study was to isolate and identify probiotic lactic acid bacteria from traditional yogurt in Varamin province. 32 samples of traditional yogurt were collected from Varamin and lactic acid bacteria were isolated and identified based on biochemical tests. The probiotic properties of the bacteria were determined based on acid tolerance test and bile salt stability test. After molecular identification by PCR and sequencing of some samples the isolated bacteria were identified at the genus and species level. Nine lactic acid bacteria were isolated and identified. Seven lactic acid bacterial isolates were isolated from bovine yogurt samples and 2 isolates from sheep yogurts. Morphological and biochemical properties and fermentation ability of sugars were investigated by isolated lactic acid bacteria. In acid tolerance test, 8 acid-resistant strains were reported and all 9 non-acid-resistant strains were resistant to bile salts. All 9 isolates contained 16srRNA gene. The results of sequencing three isolates showed the presence of one Lactobacillus casei and two Enterococcus faecium. Most of the lactic acid bacteria isolated in this study had probiotic properties.
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