RESUMO
This study was conducted to investigate the probiotic properties of twenty lactic acid bacteria (LAB) previously isolated and identified from naturally fermented kunun-zaki (a Nigerian fermented cereal beverage). The probiotic properties of the twenty lactic acid bacteria (LAB) isolates were assessed using different standard methods and agar well diffusion method. The results showed that most of the isolates tolerated acidic pH and survived at 30-40oC. All the tested LAB isolates grew at 1% NaCl concentration and remarkably, six LAB isolates {L. brevis (3) and L. plantarum (3)} exhibited good growth at higher NaCl concentrations (10-15%). The highest percentage of cellular auto-aggregation was observed in L plantarum (84.86%) and the lowest was obtained in L. brevis (27.44%). All the twenty LAB isolates tested in-vitro in this study grew in bile salt; fermented glucose; produced good aroma; produced no hemolysis revealing they were not pathogenic and produced antagonistic activity against selected pathogens (Staphylococcus aureus, Salmonella typhi, Shigella. dysenteriae and Escherichia coli) which made them suitable and safe for human consumption as potential probiotics and for industrial purposes.
RESUMO
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.