The lactic acid bacteria, Lactiplantibacillus plantarum KU15149 and Levilactobacillus brevis KU15176 were verified through phenotypic and genotypic analyses. Safety evaluation was conducted using multiple assays, including minimum inhibitory concentration assay for nine antibiotics, hemolytic activity, mucin degradation, gelatin liquefaction, urease activity, indole production, β-glucuronidase activity, bile salt deconjugation, cell cytotoxicity, D-/L-lactic acid production, and biogenic amine formation. Genotypically L. plantarum KU15149 and L. brevis KU15176 lacked all virulence and antibiotic resistance genes investigated. Consistent with these results, phenotypic assays showed that both strains were susceptible according to EFSA cut-off values and tested negative for hemolysis, mucin degradation, gelatin liquefaction, urease activity, indole production, β-glucuronidase activity, and bile salt deconjugation. Furthermore, neither strain showed cytotoxicity toward Caco-2 cells at a multiplicity of infection of 250. Production of D-lactic acid and biogenic amines was negligible in both bacteria. Overall, L. plantarum KU15149 and L. brevis KU15176 demonstrated safety and beneficial characteristics and therefore could serve as probiotic strains.

Animal experiments have demonstrated the effectiveness of fermented rice germ and soybean extracts in lowering blood alcohol concentration. A compound primarily derived from fermented soybean extract constitutes the principal component of DA-5521, an experimental dietary substance examined in this study. We investigated the possible hangover-alleviating effects of DA-5521 in individuals aged 19 to 50 who had previously experienced hangovers. Moreover, we enrolled 22 participants who met the eligibility criteria and conducted a double-blind, randomized, placebo-controlled crossover trial. Six hours after alcohol consumption, the test group exhibited a statistically significant reduction in blood acetaldehyde concentration compared with the placebo group. Further, our results displayed significantly lower levels in the DA- 5521 group at 0.50 and 0.75 h post-ingestion and substantially lower peak breath alcohol concentration compared to the placebo group. These findings confirm that consumption of DA-5521 can significantly ameliorate hangover symptoms by diminishing blood acetaldehyde concentration and reduce breath alcohol concentration.

This study aimed to identify and characterize lactic acid bacteria strains with antimicrobial activity against Proteus mirabilis, a gram-negative bacterium associated with Parkinson’s disease, Crohn’s disease, and nosocomial infections. Among the 987 lactic acid bacteria strains isolated from various sources, strain no. CHK903 showed high antimicrobial activity against P. mirabilis. Phylogenetic tree analysis based on the 16S rRNA gene and scanning electron microscope analysis identified the selected strain as the rod-shaped Weissella cibaria. The culture supernatants of W. cibaria CHK903 showed antimicrobial activity against some pathogens. Two antimicrobial compounds with molecular weights 189 and 365 Da were partially purified from the culture supernatants of W. cibaria CHK903 using Biogel P2 gel permeation column chromatography. The culture supernatants of W. cibaria CHK903 also showed significant antibiofilm properties, inhibiting biofilm formation by 90% and removing pre-formed biofilms by 60%. These findings suggest the potential therapeutic use of W. cibaria CHK903 as a natural antimicrobial against P. mirabilis-related infections.

Oligosaccharide-producing lactic acid bacteria were isolated from young radish and identified as Weissella cibaria YRK005. Oligosaccharides from W. cibaria YRK005 were purified using size-exclusion high-performance liquid chromatography, and their structure was determined. The oligosaccharides consisted of glucose only, 1 H-nuclear magnetic resonance analysis revealed that the oligosaccharides consisted of 93.8% α-1,6 glycosidic linkages and 6.2% α-1,4 glycosidic linkages, and molecular weight was determined to be 1.1210 2 Da. When the oligosaccharides' prebiotic effect on probiotic strains was examined, the oligosaccharides promoted the growth of four probiotic strains, Bifidobacterium adolescentis, Lactobacillus acidophilus, Lactococcus lactis, and Lactobacillus pentosus, compared to fructo-oligosaccharides as a reference. These results indicated that oligosaccharides from W. cibaria YRK005 could be used as potential prebiotics.

1-Deoxynojirimycin (DNJ), an alpha-glucosidase inhibitor, has been used to prevent or treat type 2 diabetes. Low amounts of DNJ are found in mulberry leaf; however, a methodology is necessary to enhance the DNJ content of mulberry leaf extract (MLE) since increasing the amounts of DNJ is required for the prevention and treatment of type 2 diabetes. In this study, the DNJ content of MLE was increased through the optimization of the conditions for MLE fermentation by Lactobacillus plantarum SG-053, using response surface methodology (RSM). By single factor testing, the optimal conditions were identified as an inoculum concentration of 1%(v/v), an MLE concentration of 3°Bx, and no agitation. Based on a Plackett-Burman design, the following factors were considered to majorly affect the DNJ content in the MLE fermentation product: the initial pH, fermentation temperature, and fermentation time. By response surface methodology, the optimal conditions for MLE fermentation was found to have an initial pH of 5.5, a fermentation temperature of 31.9oC, and a fermentation time of 34 h. Under these optimal fermentation conditions, the DNJ content in MLE increased 3.59 times, or from 23.85 to 85.54 μg/mL.

본 연구에서는 메주에서 분리된 C. allociferrii JNO301 을 이용한 최적 홍삼 ginsenosides의 생물전환 조건을 확인한 결과, 1.0% (v/v)의 홍삼 추출물에 탄소원으로서 2.5%(w/ v)의 galactose, 질소원으로서 1.0% (w/v)의 soytone을 첨가 하여 30oC에서 145 rpm으로 8일간 배양을 최적 생물전환 조건으로 확립하였다. C. allociferrii JNO301에 의해 홍삼 추출물에 존재하는 Rb1, Rb2, Rc, Rf가 생물전환되어 F2, Rh1, Rh2, compound O, compound Mc1, compound K 등 의 minor ginsenosides의 함량이 증가되었다.