Isolation and Characterization of Enterococcus faecium from Fermented Korean Soybean Paste with Antibacterial Effects

• Published in: Fermentation (Basel) Vol. 9; no. 8; p. 760
• Main Authors: Han, Kiseok, Park, Soyoung, Sathiyaseelan, Anbazhagan, Wang, Myeong-Hyeon
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-08-2023
• Subjects: antibacterial; Antibacterial activity; Antibiotics; Bacteria; Bile; biocompatibility; Drug resistance; Enterococcus faecium; Enterococcus spp; Fermented food; Food; Free radicals; Gentamicin; Heat resistance; Hydrochloric acid; Hydrophobicity; lactic acid bacteria; Microbiota; Microorganisms; Oxidants; Pathogens; Probiotics; Salt; Soybeans; Sulfonic acid; United Kingdom > UK; United States > US; South Korea
• ISSN: 2311-5637; 2311-5637
• DOI: 10.3390/fermentation9080760

In the present study, a total of eight Enterococcus faecium (OQ940301, OQ940302, OQ940303, OQ940304, OQ940305, OQ940308, OQ940309, and OQ940310) were isolated from soybean paste, a traditional Korean fermented food, and evaluated for their probiotic properties. The results showed that all the E. faecium strains survived in simulated human gastrointestinal conditions (4.1–5.59 log10 CFU/mL). In addition, the range of auto-aggregation was 5–25%, the hydrophobicity was around 94%, and it exhibited significant co-aggregation ability with Salmonella enterica and Staphylococcus aureus. However, all the isolates were shown to be resistant to Gentamycin. The bacterial cell-free supernatant showed antibacterial activity against S. enterica, Escherichia coli, Bacillus cereus, Listeria monocytogenes, and S. aureus. Furthermore, E. faecium exhibited potent anti-oxidant activity by scavenging 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) free radicals. In addition, safety was confirmed by evaluating the hemolytic activity in blood agar; none of the bacterial isolates showed hemolysis. These results demonstrated that E. faecium (OQ940301 and OQ940309) isolated from soybean paste showed a higher probiotic potential.