Probiotic and technological potential of Enterococcus faecium EM03, isolated from Brazilian semi-hard cheese

Probiotics have attracted increasing interest from consumers due to their potential health benefits, antimicrobial properties, and overall wellness support. In this context, it is essential to identify new bacterial strains that exhibit significant functional characteristics and enhanced stability to food processing. This study aimed to identify and assess the technological and probiotic properties of Enterococcus faecium EM03, which was isolated from semi-hard cheese commercialized in Barreiras, Bahia, Brazil. The isolate was genotypically confirmed as E. faecium through 16S rRNA gene sequencing. In vitro safety assessments revealed sensitivity to most of the antibiotics tested, with resistance observed only to ciprofloxacin and gentamicin. Molecular analyses indicated the absence of genes associated with the production of biogenic amines and several virulence factors. Conversely, the presence of genes linked to bacteriocin production, specifically ent B, ent P, L50AB, Ian M, and Ian C, was confirmed. These findings were further supported by results from the spot-on-the-lawn assay, which demonstrated that E. faecium EM03 inhibited the growth of Listeria monocytogenes and E. faecalis through the production of proteinaceous compounds. Regarding its probiotic potential, the isolate exhibited high survival rates under simulated gastrointestinal conditions, including tolerance to pH 3.5, to pepsin treatment, and to bile salts. Additionally, microencapsulation by spray-drying allowed the survival to in vitro gastrointestinal tests and preserved probiotic viability for up to 60 days, with stable physical properties of the microparticles. Overall, the results indicate E. faecium EM03 has technological potential for food and health-related applications.