54 ISSN 1120-1770 online, DOI 10.15586/ijfs.v35i2.2316 P U B L I C A T I O N S CODON Italian Journal of Food Science, 2023; 35 (2): 54–70 P U B L I C A T I O N S CODON Evaluation of the Functional Properties and Safety of Enterocin-producing Enterococcus faecium BT29.11 Isolated from Turkish Beyaz Cheese and its Inhibitory Activity against Listeria monocytogenes in UHT Whole Milk Melike Seda Toplu, Banu Özden Tuncer* Faculty of Engineering, Department of Food Engineering, Süleyman Demirel University, Isparta, Türkiye *Corresponding Author: B. Özden Tuncer, Süleyman Demirel University, Faculty of Engineering, Department of Food Engineering, 32260, Isparta, Türkiye. Email: banutuncer@sdu.edu.tr Received: 22 December 2022; Accepted: 13 April 2023; Published: 9 May 2023 © 2023 Codon Publications OPEN ACCESS ORIGINAL ARTICLE Abstract Te goal of this research was to evaluate the functional properties and safety of antilisterial Enterococcus faecium BT29.11 isolated from Turkish Beyaz cheese. E. faecium BT29.11 showed the highest inhibitory activity against Listeria monocytogenes, followed by Staphylococcus aureus and vancomycin-resistant enterococci. E. faecium BT29.11 was identifed by 16S rDNA sequence analysis, and genus- and species-specifc PCR. Te entA, entB, and entX struc- tural genes were detected in E. faecium BT29.11. It was determined that the BT29.11 strain was a slow acid producer and did not show extracellular proteolytic and lipolytic activity. E. faecium BT29.11 demonstrated good probiotic properties. E. faecium BT29.11 was found to be ɣ-hemolytic, gelatinase-negative, and susceptible to clinically import- ant antibiotics. Only ermC and acm were detected in the BT29.11 strain. E. faecium BT29.11 decreased the growth of L. monocytogenes in ultra-high temperature (UHT) milk. Te fndings of this research indicated that E. faecium BT29.11, an antilisterial strain, might be employed as a probiotic adjunct culture in fermented food products. Keywords: beyaz cheese; enterocin; Enterococcus; probiotic; safety evaluation Introduction Enterococci are lactic acid bacteria (LAB), which are most commonly found in the digestive tracts of humans and animals but may also be found in food and the sur- rounding environment (Foulquié Moreno et al., 2006; Graham et al., 2020). Enterococci are frequently iso- lated from cheese due to their resistance to pasteuriza- tion temperatures and their ability to adapt to diferent substrates and growth conditions such as low and high temperatures, low pH levels, and salt concentrations (Cariolato et al., 2008; Özden Tuncer et al., 2013; Terzić- Vidojević et al., 2021; Yogurtcu and Tuncer, 2013). In addition, studies on the microbiota of traditional cheeses produced in many Mediterranean countries, such as France, Greece, Italy, Portugal, Spain, and Türkiye, have shown that enterococci play an important role in the rip- ening of these cheeses through proteolysis, lipolysis, and citrate degradation and contribute to their typical taste and aroma (Dapkevicius et al., 2021; Foulquié Moreno et al., 2006). However, these bacteria also improve the microbiological safety of dairy products by produc- ing antimicrobial compounds, including bacteriocin called enterocin (Hanchi et al., 2018; Kahn et al., 2010). According to Franz et al. (2007), enterocins are classi- fed into four classes: lantibiotic enterocins, including cytolysin and enterocin W, which are considered two- component lantibiotics (class I); non-lantibiotic entero- cins (class II); cyclic enterocins, such as enterocin AS-48 (class III); and large molecular weight proteins, such as enterolysin A (class IV). Class II is also divided into three subclasses: pediocin-like enterocins, such as enterocin A