Nadia Ramezani, - Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran
Mozhdeh Torkzaban - Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran
Mohammad Pooya Naghshbandi - Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran

Probiotic microorganisms are nutritional supplements that play an important role in human health. Daily use of industrial dairies has led to an increase in the elimination of these probiotics. The purpose of this experiment is to isolate acid-resistant probiotic microorganisms with a rapid growth rate from local yogurts in Golpayegan and use them in industrial production. Material and Method: In this experiment, which was carried out in 2018, Microorganisms were isolated from a sample of local yogurts in Golpayegan province using MRS. Resistance effects of these microorganisms on gastric and uric acid were investigated through culture in acidic media, also their effect on pathogenic microorganisms was analyzed using disk diode method. Results: At this stage, acidresistant yeasts were found in a specific culture medium (MRS). After culture in acidic media, the resistance to pH 2.5 was confirmed. The diameter of the growth halo of pathogenic bacteria was also measured. Result: The isolated yeast has a much higher growth rate than other microorganisms within the medium and has the ability to colonize in the acidic environment of the stomach and intestines. It also has the ability to prevent the growth of pathogenic bacteria.

Probiotic, Acid resistance, Yoghurts, Golpayegan