This study aimed to characterize the safety and technological properties of Enterococcus faecium strains isolated from Brazilian Coalho cheeses. High levels of co-aggregation were observed between Enterococcus faecium strains EM485 and EM925 and both Escherichia coli and Clostridium perfringens . Both strains presented low levels of hydrophobicity. E. faecium EM485 and EM925 were both able to grow in the presence of 0.5% of the sodium salts of taurocholic acid (TC), taurodeoxycholic acid (TDC), glycocholic acid (GC), and glycodeoxycholic acid (GDC), although they showed the ability to deconjugate only GDC and TDC. Both strains showed good survival when exposed to conditions simulating the gastro intestinal tract (GIT). When tested for the presence of virulence genes, only tyrosine decarboxylase and vancomycin B generated positive PCR results.

Based on screening for potential beneficial lactic acid bacteria from Coalho cheese produced in the North-East region of Brazil, eight strains belonging to Lactobacillus rhamnosus and Lactobacillus plantarum were selected. All investigated strains presented low levels of hydrophobicity. Different levels of coaggregation were Dairy Sci. & Technol. (2015) 95:209-230 DOI 10.1007 observed for tested Lb. rhamnosus and Lb. plantarum with Listeria monocytogenes. All strains were able to grow in presence of 0.5% of the sodium salts of taurocholic acid (TC), taurodeoxycholic acid (TDC), and glycocholic acid (GC) and showed the ability to deconjugate only TC, TDC, and GC. Investigated Lb. rhamnosus and Lb. plantarum strains showed good survival when exposed to the conditions simulating the GIT conditions. Lb. rhamnosus and Lb. plantarum strains were tested for presence of virulence, antibiotic resistance, and biogenic amine production genes. In addition, minimum inhibititory concentration (MIC) of selected antibiotics was determined. Production of antimicrobial peptides (bacteriocins) was investigated. However, only Lb. rhamnosus EM253 produced bacteriocin at level 800 arbitrary unit (AU) mL −1 against L. monocytogenes 211. The bacteriocin remained stable at pH from 2.0 to 10.0 and after exposure at 100°C for 120 min and in presence of surfactants and salts. Studied Lb. rhamnosus and Lb. plantarum strains showed good potential to be applied as a functional coculture/s with beneficial properties in the production of Coalho cheese.

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