Akademik Veri Yönetim Sistemi
4th Eurasia Biochemical Approaches & Technologies (EBAT), Antalya, Türkiye, 3 - 06 Kasım 2022, ss.120
Since lactic acid bacteria contribute significantly to the nutritional value of products due to their metabolic properties and the metabolites they produce, food technology has been a very important bacterial group in terms of food microbiology for many years. The interest in this group of microorganisms has increased considerably at the point of preventing food spoilage and extending the shelf life of foods. The prolongation of the shelf life of LAB in foods comes from the antimicrobial metabolites they produce such as organic acids, antibiotics, hydrogen peroxide, acetoin, bacteriocin. Bacteriocins are ribosomally synthesized antimicrobial compounds produced by many different bacterial species, including many members of lactic acid bacteria (LAB).1 Some bacteriocins such as "nisin", which have the most common use in the food industry, are effective against many foodborne pathogens. For this reason, bacteriocins have been used as natural food preservatives in recent years and have come to a very important point in the food industry. The direct addition of bacteriocins and bacteriocin-producing cultures to food has revealed very important results in terms of food safety. As a result of these effects, LAB has been accepted as generally recognized as safe (GRAS).2 In our current study, our aim is to isolate and identify bacteriocinogenic lactic acid bacteria from white cheese samples, to examine their antimicrobial effects on pathogenic food microorganisms and to evaluate their usability in terms of food safety. For this purpose, 41 bacteria were isolated from white cheese samples collected from different regions of Turkey and these isolates were characterized phenotypically. Then, these isolates were distinguished from each other on a species basis by genomic fingerprint analysis. Antimicrobial properties of the isolates were determined in order to make a preliminary estimation of whether the isolates thought to be different produce bacteriocins. Various gram positive and gram negative food pathogens were used. Specific PCR analysis was performed to determine whether the antimicrobially positive isolates contain certain bacteriocin genes (Plantaricin, Lactocococin, Pediocin, Brevicin, Nisin, Epidermicin, Enterocin). As a result of the analyzes, it was determined that the isolate coded MA33 showed strong antimicrobial effect against Staphylococcus aureus, Bacillus cereus and Escherichia coli, and this isolate was a strong bacteriocin (nisin and plantaricin) producer. The isolate, which has antimicrobial effect and bacteriocin production potential, which is a very important criterion in terms of food safety, was then genomically identified. As a result of the diagnosis, it was determined that the bacterium was 99% similar to Staphylococcus hominis.