Genetic identification and evaluation of antibacterial activity of lactic isolates derived from Masske butter against pathogenic bacteria Staphylococcus aureus and Salmonella enterica

Masske butter or butter derived from yogurt is a traditional butter used in southern Khorasan with a wide range of lactic bacteria. The aim of this study was to investigate the antibacterial effect of lactate isolates against of Staphylococcus aureus and Salmonella enterica. In this research, lactic isolates were first detected by PCR method, and then microdilution method was used to evaluate the antimicrobial activity of the isolates. BLAST of sequences of S16 rDNA gene with sequences stored in the NCBI database led to the identification of the genus Lactobacillus bulgaricus, Enterococcus faecium, Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus delbrueckii and Enterococcus hirae. The results of antimicrobial activity evaluation against Staphylococcus aureus and Salmonella enterica bacteria showed that all isolates were able to inhibit the growth of these two pathogens, and their inhibitory percent from 55/46 to 84/49 and from 55/46 to 56/55 respectively was variables. Also, the results showed that Lactobacillus plantarum B38, Enterococcus hierae B224, Lactobacillus delbrueckii B37 had the highest inhibitory effect against Staphylococcus aureus (P>0.05) and Lactobacillus plantarum B38 showed the highest percentage of inhibition against Salmonella enterica (P<0.05). In addition, it was found that the inhibitory effect of all isolates against Staphylococcus aureus was significantly higher than Salmonella enterica (P< 0.05). Therefore, lactic acid bacteria isolated from the Masske butter can be used to control the food borne pathogens and food spoilage microorganisms.