Investigation of the bactriocin effect of lactic acid probiotic bacteria isolated from dairy products of Nadushan region, Yazd

Background: Among probiotics, lactobacillus species with bacteriocin activities have been used in microbial biotechnology as safe biological preservatives. So, this study aimed to determine antimicrobial activity of bacteriocins of lactobacillus species isolated from lactic acid bacteria in traditional dairy products. Materials and Methods: In this experimental study, isolated lactic acid bacteria from local yoghurt of Nadushan region were used as probiotics with a bacteriocin production potential. The bacteriocin effect of isolated lactic acid bacteria was investigated against seven pathogenic bacteria using well diffusion and disk methods. Results: The results of well diffusion analysis showed that the most growth inhibitory effect against Staphylococcus epidermidis, Escherichia coli Staphylococcus aureus, Enterococcus faecalis and Candida albicans pathogen bacteria was caused by isolated lactic acid bacteria including Lactobacillus delbrucki, Lactobacillus caesium and Lactobacillus plantarum, respectively. Also, the results of disc method showed that the highest inhibitory effect against the bacterial pathogens was caused by Lactobacillus delbrucki, Lactobacillus plantarum and Lactobacillus caesium, respectively. Although antimicrobial compounds were inactivated by proteolytic enzymes, they showed stability against variant pH and temperature treatments. Conclusion: It seems that bacteriocin of the probiotics isolated from dairy products of this region can be used as a safe and healthy biological preservative in food industry