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This study aimed to assess the safety and antimicrobial properties of Enterococcus species isolated from raw goat milk and cheese. The isolates were evaluated for hemolytic activity on blood agar plates and antibiotic susceptibility by determining the minimum inhibitory concentrations (MICs) of five antibiotics: ampicillin, tetracycline, gentamicin, streptomycin, and vancomycin. Furthermore, the antagonistic activity of the Enterococcus strains against indicator bacteria was assessed using the agar-well diffusion method. Hemolytic activity results demonstrated a-hemolysis in all isolates. Among the 71 Enterococcus isolates examined, 32.39% exhibited resistance to at least one antibiotic, with resistance profiles varying between species. Enterococcus faecalis isolates predominantly showed resistance to vancomycin, ampicillin, tetracycline, and gentamicin, while Enterococcus faecium and Enterococcus hirae displayed resistance to vancomycin with different susceptibility patterns to the other antibiotics. The antagonistic assays revealed a broad spectrum of inhibitory effects, with variation in inhibition zone diameters. These findings provide valuable insights into the safety and antimicrobial potential of Enterococcus spp. from raw goat milk and cheese and give an insight into their potential applications in the food industry.

This study investigates the community of coagulase-negative staphylococci (CNS) in samples of Sjenica sheep's ham from different villages across three seasons over a 120-day maturation period. The CNS group was identified into five distinct species: Staphylococcus epidermidis, S. saprophyticus, S. carnosus, S. xylosus, and S. equorum. The safety evaluation revealed no hemolytic activity in any tested isolates, while resistance to novobiocin was observed in S. xylosus and S. saprophyticus isolates. The technological properties of the isolated CNS were assessed, including tolerance to different temperatures, pH values, salt concentrations, as well as proteolytic and lipolytic activity. Results demonstrated the ability of all tested isolates to grow across various pH values and salt concentrations, with isolates of S. carnosus and S. epidermidis showing tolerance to 45°C. The best technological properties were shown by S. carnosus, followed by S. equorum. These findings provide insights into the potential applications of CNS in food processing industries, as putative starters.

The aim of this study was to determine the antifungal activity of extracts and isolated substances from the root of Onosma visianii Clem. (Boraginaceae) by determining the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC). The results show that antifungal activity depends on species of microorganism and the type of substances or extracts. All tested substances showed selective and moderate antifungal activity. MIC and MFC values for the extracts ranged from

In this paper, we investigated, for the first time, the enzyme activity of enterobacteria from cheese from Southeastern Serbia (Sokobanja), which was produced in a traditional way. The tested bacteria were selected from the spring, summer, and autumn collections and grown in two different broths. The enzyme activity was investigated in the two broths and measured using spectrophotometry method. It was concluded that there were differences in the amount of extracellular enzymes depending on the broths. A statistically significant rise in the amount of enzymes was demonstrated in Tripton soy broth. Bacteria in cheese do not possess the ability to produce extracellular enzymes in large amounts. Therefore, they do not change the organoleptic characteristics of the cheese. There is a possibility that if they are found outside their natural environment (cheese), without interactions with antagonists, they may exhibit stronger enzyme activity.

The purpose of this study was the investigation of the growth ability of lactic acid bacteria (LAB), isolated from traditionally made cheese from Southeastern Serbia, in the presence of different percent of sugars and sugar substitutes (fructose, lactose, inulin, and mannitol). Dextrose was included for comparative purposes. The results indicated that fructose and lactose stimulated the growth of Lactobacillus strains, with exceptions of Lactobacillus plantarum KGPMF62 and Lb. plantarum LP 299v. Lactose showed similar effects like dextrose on the growth of Lactococcus strains, while higher growth rates of Enterococcus hirae KGPMF9, E. durans KGPMF10, E. faecium KGPMF14, and E. faecalis KGPMF47 were observed for lactose and mannitol. The results indicated the potential use of tested sugars and sugar substitutes as prebiotic compounds for the development of symbiotics with tested LAB, in medical or food industry.

This study observed the preliminary investigation of Oleum Hyperici, an original product made from Hypericum perforatum flowers, collected from Goč Mountain (Serbia). Some of the chemical properties (pH, the content of metals and metalloids - As, Cr, Pb, Cd, Ni, Hg) and the microbiological safety of the product including the total count of aerobic mesophilic bacteria, coagulase positive staphylococci, Escherichia coli, Pseudomonas aeruginosa, Proteus sp., as well as fungi: molds and yeasts) were evaluated. Antimicrobial activity of H. perforatum oil against 18 species of bacteria was determined using the disc diffusion and microdilution methods, by determining the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The antibiofilm activity of Oleum Hyperici was evaluated using the biofilm formation assay. The results indicated that oil did not contain potentially pathogenic microorganisms. Oleum Hyperici product showed the antimicrobial activity on the most of tested bacteria (inhibition zone was in a range from 14 - 24 mm), except on Klebsiella pneumoniae ATCC 70063, K. pneumoniae, E. coli ATCC 25922, P. mirabilis, Bacillus subtilis ATCC 6633 and B. subtilis IP 5832. According to the obtained results, tested bacteria (planktonic and biofilm form) showed sensitivity up to 10-2 dilution of Oleum Hyperici. Based on the obtained preliminary results, it could be concluded that Oleum Hyperici can be used in traditional medicine for development control of some potential human pathogens.