Isolation of lactic acid bacteria generating bacteriocin from pot cheese
Faezeh Nasrollahi nia,
1,* Mahdi bayrami,
2 Amir ganjkhanlu,
3 Asghar zahed,
4 Mohsen azizi,
5 Sanaz alioghli,
6
1. department of biology, factuly of science, university mohaghegh ardabili
2. department of biology, factuly of science, university mohaghegh ardabili
3. faculty of veterinary medicien, azad university of tabriz, tabriz, iran
4. faculty of veterinary medicien, azad university of tabriz, tabriz, iran
5. faculty of veterinary medicien, azad university of tabriz, tabriz, iran
6. department of biology, factuly of science, university mohaghegh ardabili
Abstract
Introduction
In fermented foods, lactic acid bacteria (lab) display numerous antimicrobial activities. this is mainly due to the production of organic acids, but also of other compounds, such as bacteriocins and antifungal peptides. several bacteriocins with industrial potential have been purified and characterized. lactic acid bacterias generate bacteriocin through lactic fermentation, whichis antimicrobial protein. hence, this investigation was manipulated to evaluate and measurethe ability of lactobacilli in pot cheese to produce and secrete bacteriocin and determine itsinfluences on five strains of bacteria in foodborne diseases.
Methods
In this way, isolated strains were incubated in mrs broth medium at 37 ° c. after that the cultures were centrifuged at 10,000 rpm for 10 minutes and subsequently the supernatant solution was removed. to verify antimicrobial activity due to the production of bacteriocin, the ph of the supernatant solution was adjusted to 6.5 to 7. in mueller hinton agar, 100 μl of each bacterial strain was incubated. the wells were then placed on inoculated medium and 200 μl of supernatant solution was poured into the wells and incinerated at 37 ° c for 48 hours, and subsequently, the wells around them were aureoles which has the lack of growth was considered as antimicrobial agent strain.
Results
31 strains with strong antibacterial activity were identified from the lactic acid bacteria which are isolated from pot cheese. the isolated strains presented a significant inhibitory effect on staphylococcus aureus, escherichia coli, bacillus cereus and less inhibitory effect on listeria monocyte genes and yersinia enterocolitica.
Conclusion
According to the results of the study, these isolated materials can be used as strains of natural preservatives in dairy industry.
Keywords
Lactic acid bacteria, bacteriocin, antimicrobial, pot cheese
