[P008] Poster

1:00 PM - 1:50 PM JST(4:00 AM - 4:50 AM UTC)

[P04-480] In Vitro Probiotic Assessment of Lactic Acid Bacteria Isolated from Kimchi, a Traditional Korean Fermented Food

○HyeJin Hong¹, MyeongGi Cha¹, SoYeong Hwang¹, JeongAh Yoon², MyoungDong Kim^1,2 (1. Department of Food Science and Biotechnology, Kangwon National University (Korea), 2. Institute of Fermentation and Brewing, Kangwon National University (Korea))

Keywords:

Probiotic,Lactic acid bacteria,Antimicrobial activity,Acid tolerance,Bile tolerance

Probiotics are beneficial microorganisms that may contribute to host health by influencing the balance of microbes in the gut. Growing interest in health-promoting foods has increased the demand for new probiotic strains with better functionality and stability. However, because probiotic properties depend on the strain, systematically evaluating individual strains is crucial for identifying promising candidates. In this study, the in vitro probiotic properties of 11 lactic acid bacteria (LAB) isolated from the Korean fermented food Kimchi were assessed, including three strains of Lacticaseibacillus paracasei, five strains of Lactiplantibacillus brevis, two strains of Leuconostoc mesenteroides, and one strain of Pediococcus acidilactici. Lacticaseibacillus rhamnosus GG (LGG), a widely used commercial probiotic strain, was used as a reference. Antimicrobial activity was evaluated using a disk diffusion assay against six pathogenic or spoilage bacteria: Bacillus cereus KCTC 3624, Staphylococcus aureus KCTC 1916, Escherichia coli O157:H7 KCCM 40406, Listeria monocytogenes KCTC 3569, Micrococcus luteus KCTC 3063, and Pseudomonas fluorescens KCTC 4282. Acid tolerance was evaluated at pH 3.0 for 4 h, bile tolerance in 0.3% (w/v) oxgall for 4 h, and hemolytic activity on blood agar plates. All isolates exhibited antimicrobial activity against the six tested bacteria. Among them, L. brevis MBE/L9133 demonstrated the largest inhibition zones against five species: B. cereus (27.27 ± 0.09 mm), S. aureus (21.28 ± 0.21 mm), E. coli O157:H7 (30.12 ± 0.23 mm), M. luteus (25.73 ± 1.42 mm), and P. fluorescens (18.42 ± 0.80 mm), showing 1.07- to 1.59-fold greater activity than LGG. L. mesenteroides MBE810 exhibited the strongest activity against L. monocytogenes (12.67 ± 0.12 mm), which was 1.07 times larger than that of LGG. In acid tolerance tests, all strains except L. mesenteroides MBE810 showed growth comparable to or greater than LGG. All strains also showed bile tolerance, with L. brevis MBE/L9137 and L. mesenteroides MBE813 demonstrating particularly high resistance. Additionally, all tested strains were non-hemolytic. These results showed that L. brevis MBE/L9133, MBE/L9137, and L. mesenteroides MBE813 demonstrated superior antimicrobial activity, acid tolerance, bile tolerance, and non-hemolytic properties. These findings highlight their potential as probiotic candidates for use in functional foods and starter cultures