Zahra Mammadzade, Sabina Ojagverdiyeva, Malahat Gulahmadova, Konul Bakhshalieva, Abdul Matin, Svetla T. Danova, Saib Gulahmadov
Abstract
Abstract
Lactic acid bacteria (LAB), which have GRAS status, have been used since ancient times by representatives of different civilizations as starter or co-cultures for the production of various fermentation products. As part of these products, they transform carbohydrate components to fermentation and synthesize a large amount of lactic acid, which, creating an acidic environment, first - gives the products pleasant taste and organoleptic properties, the second - prevents the development of accompanying microbial populations and protects them from spoilage and contamination pathogens. Along with lactic acid, LAB produce many metabolites with antimicrobial properties. Important of them are BLIS (Bacteriocin – like inhibitory substances), active peptides - synthesized on ribosomes and post-translationally modified. With selective antimicrobial activity, these peptides usually affect closely related species, but some have strong activity against pathogenic and opportunistic microbes. Thus, interest in them is increasing everyyear.
In the present work, two previously isolated from three samples of Apsheron white cheese, were unidentified as bacteriocinogenic strains. Primary screening was carried out using “direct plating” method.The antimicrobial activity of isolated strains was determinedby the variants of agar diffusion method. The strains were active against gram-positive and gram-negative bacteria, including L. monocytogenes, S. aureus, L. brevis and E. coli. The maximum titer of the BLIS produced was found in the cultivation medium at the end of the exponential growth phase of the LAB cultures, which defines them as the primary metabolites. Phenotypic identification of active strains revealed their belonging to two species of the genus Enterococcus: E. faecium P1-3 and E. faecalis P3-2.