In vitro assessment of native probiotic bacteria isolated fromLorestan Nomads Dairies

Background and Aim : Background and aim: A global surge in the application of probiotics asfunctional ingredients in food, animal feed, and pharmaceutical products has been increased in lastdecades. The largest sector in food industry is belonged to dairy products where probiotics areemployed in sour/fermented milk, yogurt, cheese, butter/cream, ice cream, and infant formula.Many functional characteristics are devoted to dairies using probiotics like improved aroma, taste,textural characteristics and health-promoting properties. One of the most important trends forincorporation of probiotics in dairies is fermentation of dairy products with probiotics isolatedfrom traditional foods or dairies. In this research we isolate, characterize and survey probioticactivity of strains from traditional dairies collected from Lorestan nomads of Iran.Methods : Eleven different samples of yogurt, cheese, milk, butter, kashk and Dough are collectedfrom nomads migrated to hills near Khoramabad city, Lorestan province. The dairies were thendirectly transferred to the lab and isolation process were carried on MRS agar, M۱۷ agar, TSA andYPG agar. In vitro probiotic assessment of isolated strains were done according to Guidelines forthe Evaluation of Probiotics in Food (FAO/WHO, ۲۰۰۲) and Iranian National Standard No. ۱۹۴۵۹.Finally, the native probiotic candidates were identified by rDNA sequencing and phenotypiccharacterization.Results : From total ۱۲۴ strains which have been isolated from samples at first step, only fiveisolates passed all criteria and showed probiotic features. Three of these strains have been isolatedfrom yogurt (Y.L III (۲۵), Y.L III (۷), Y.L IV (۴)); one of them from Kashk (K.L ۲(۱۰)) and thelast one from Doogh (D.L II (۱)). The rDNA sequencing results demonstrate that strains Y.L III(۲۵) and D.L II (۱) belonged to family Saccharomycetaceae and showed the highest similarity withkluyveromyces marxianus and Pichia fermentans, respectively. The other strains include Y.L III(۷), Y.L IV (۴) and K.L ۲(۱۰) belonged to family Lactobacillaceae and showed the highestsimilarity with Pediococcus acidilactici, Levilactobacillus brevis and Lentilactobacillus buchneri,respectively.Conclusion : Native probiotics are advantageous for utilization at industrial scales. Some isolatesfrom this research are ideal probiotic candidates which can be applied in the field for theimprovement of taste and health of dairies.

کلیدواژه ها:

Lactic acid bacteria ، probiotics ، Lorestan dairies ، native bacteria