• Microbiology and Biotechnology Letters
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• v.51 no.1
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• pp.128-131
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• 2023

Here we report the draft genome sequence of Weissella koreensis strain HJ and genomic analysis of its key features. The genome consists of 1,427,571 bp with a GC content of 35.5%, and comprises 1,376 coding genes. In silico analysis revealed the absence of pathogenic factors within the genome. The genome harbors several genes that play an important role in the survival of the gastrointestinal tract. In addition, a type III polyketide synthase cluster was identified. Pangenome analysis identified 68 unique genes in W. koreensis strain HJ. The genome information of this strain provides the basis for understanding its probiotic properties.

• Journal of Dairy Science and Biotechnology
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• v.34 no.2
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• pp.75-82
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• 2016

Members of the genus Bifidobacterium are prevalent in the human colon and represent up to 90% of all bacteria in fecal samples of breast-fed infants, and 3~5% of adult fecal microbiota. Bifidobacteria produce organic acids, thus reducing the colon pH to a level inhibitory for pathogenic bacteria. They can also detoxify a number of toxic compounds and adhere to the colon mucosa, thus preventing the adherence of pathogens and induction of colon cancer. Recently, we identified a novel Bifidobacterium longum subsp. longum strain, KACC 91563, in a fecal sample of a Korean neonate, and demonstrated its functional properties. We showed that B. longum KACC 91563 alleviates food allergy through mast cell suppression and produces antioxidative and antihypertensive peptides by casein hydrolysis. Dairy products are considered as an ideal food system for the delivery of probiotic cultures to the human gastrointestinal tract. Cheese affords protection to probiotic microbes during gastric transit due to its relatively high pH, more solid consistency, higher fat content, and higher buffering capacity. Incorporation of B. longum KACC 91563 into cheese making is currently under study.

• Journal of Microbiology and Biotechnology
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• v.32 no.6
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• pp.783-791
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• 2022

Gamma-aminobutyric acid (GABA) improves various physiological illnesses, including diabetes, hypertension, depression, memory lapse, and insomnia in humans. Therefore, interest in the commercial production of GABA is steadily increasing. Lactic acid bacteria (LAB) have widely been reported as a GABA producer and are safe for human consumption. In this study, GABA-producing LAB were preliminarily identified and quantified via GABase assay. The acid and bile tolerance of the L. plantarum FBT215 strain were evaluated. The one-factor-at-a-time (OFAT) strategy was applied to determine the optimal conditions for GABA production using HPLC. Response surface methodology (RSM) with Box-Behnken design was used to predict the optimum GABA production. The strain FBT215 was shown to be acid and bile tolerant. The optimization of GABA production via the OFAT strategy resulted in an average GABA concentration of 1688.65 ± 14.29 ㎍/ml, while it was 1812.16 ± 23.16 ㎍/ml when RSM was applied. In conclusion, this study provides the optimum culture conditions for GABA production by the strain FBT215 and indicates that L. plantarum FBT215 is potentially promising for commercial functional probiotics with health claims.

• Journal of Microbiology and Biotechnology
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• v.33 no.8
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• pp.1039-1049
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• 2023

Atopic dermatitis (AD) is a chronic inflammatory disease caused by immune dysregulation. Meanwhile, the supernatant of lactic acid bacteria (SL) was recently reported to have anti-inflammatory effects. In addition, HaCaT keratinocytes stimulated by tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) are widely used for studying AD-like responses. In this study, we evaluated the anti-inflammatory effects of SL from lactic acid bacteria (LAB) on TNF-α/IFN-γ-induced HaCaT keratinocytes, and then we investigated the strains' probiotic properties. SL was noncytotoxic and regulated chemokines (macrophage-derived chemokine (MDC) and thymus and activation-regulated chemokine (TARC)) and cytokines (interleukin (IL)-4, IL-5, IL-25, and IL-33) in TNF-α/IFN-γ-induced HaCaT keratinocytes. SL from Lacticaseibacillus rhamnosus MG4644, Lacticaseibacillus paracasei MG4693, and Lactococcus lactis MG5474 decreased the phosphorylation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK). Furthermore, the safety of the three strains was demonstrated via hemolysis, bile salt hydrolase (BSH) activity, and toxicity tests, and the stability was confirmed under simulated gastrointestinal conditions. Therefore, L. rhamnosus MG4644, L. paracasei MG4693, and Lc. lactis MG5474 have potential applications in functional food as they are stable and safe for intestinal epithelial cells and could improve atopic inflammation.

• Microbiology and Biotechnology Letters
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• v.51 no.4
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• pp.526-530
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• 2023

Here, we report the draft genome sequence of Latilactobacillus sakei subsp. sakei FBL10 isolated from Saeujeot (salted fermented shrimp). The draft genome consists of 2,285,672 bp with a G+C content of 41.1% and contains 2,282 coding genes. Genome analysis revealed that clusters associated with bacteriocin production were identified, in addition to several probiotic properties, such as stress resistance factors and aggregation. On the other hand, antibiotic resistance genes and virulence factors were not present. Pangenome analysis for 32 genomes showed 213 unique genes for FBL10 strain. These results demonstrate the beneficial properties of strain FBL10 as a putative probiotic.

• Journal of Animal Science and Technology
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• v.66 no.3
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• pp.630-634
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• 2024

Latilactobacillus curvatus CACC879 originated from swine feces in Korea, and its probiotic properties have been analyzed. The complete genome of strain CACC879 contained one chromosome 1,398,247 bp in length and three circular plasmids, namely, pCACC879-1 (591,981 bp), pCACC879-2 (14,542 base pairs [bp]), and pCACC879-3 (45,393 bp). The complete genome encodes a total of 2,077 genes, including 25 rRNA genes and 90 tRNA genes. In addition, probiotic stability- genes acid/bile related to salts tolerance, the biosynthesis of cobalamin (vitamin B12), riboflavin (vitamin B2), and CRISPR/Cas9 were found in the whole genomes. Remarkably, L. curvatus CACC879 contained the antioxidant-related (peroxiredoxin) and bacteriocin-related genes (lysM and blpA). Overall, these results demonstrate that L. curvatus CACC879 is a functional probiotic candidate for animal industry applications.

• Food Science and Preservation
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• v.24 no.8
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• pp.1168-1179
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• 2017

In this study, we tried to screen the Bacillus strain having safety probability by isolation of strains from traditional fermented food, measurement of probiotic properties, and the fermentative characteristics of Cheonggukjang. We isolated 400 Bacillus-like isolates from traditional fermented foods. Selected strains examined on the prevalent characteristic such as extracellular enzyme and antibacterial activities, and their safety probability was confirmed by biogenic amine productivity, hemolytic, and harmful substances and enzyme productivity. We selected the 5 strains by analysis of biogenic amine, antibacterial and B. cereus toxic associated gene. Five selected strains were examined on cell surface hydrophobicity, and bile and acid tolerance, and we selected the SRCM100730 as the final strain. SRCM100730 was confirmed B. amyloliquefaciens by 16S rRNA sequencing, and named the B. amyloloquefaciens SRCM100730 (KCCM11966P). Finally, we manufactured Cheonggukjang using SRCM100730 for confirmation of fermentation properties. Manufactured Cheonggukjang did not contain B. cereus, and showed that ${\gamma}$-PGA and extracellular enzyme activities were superior to commercial Chunggukjang. Amino nitrogen content was 544.02 mg% and 26 free amino acid were detected, and the bitterness-related amino acid content was lower than commercial Cheonggukjang. Especially, the amount of GABA was 3 fold higher than commercial Cheonggukjang. These results suggest that SRCM100730 have high availability in commercial probiotics market and fermented food industry.

• Journal of Microbiology and Biotechnology
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• v.32 no.1
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• pp.72-80
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• 2022

In this study, the survival capacity (acid and bile salt tolerance, and adhesion to gut epithelial cells) and probiotic properties (enzyme activity-inhibition and anti-inflammatory activities, inhibition of adipogenesis, and stress hormone level reduction) of Lactiplantibacillus plantarum LRCC5314, isolated from kimchi (Korean traditional fermented cabbage), were investigated. LRCC5314 exhibited very stable survival at ph 2.0 and in 0.2% bile acid with 89.9% adhesion to Caco-2 intestinal epithelial cells after treatment for 2 h. LRCC5314 also inhibited the activities of α-amylase and α-glucosidase, which are involved in elevating postprandial blood glucose levels, by approximately 72.9% and 51.2%, respectively. Treatment of lipopolysaccharide (LPS)-stimulated RAW 264.7 cells with the LRCC5314 lysate decreased the levels of the inflammatory factors nitric oxide, tumor necrosis factor (TNF-α), interleukin (IL)-1β, and interferon-γ by 88.5%, 49.3%, 97.2%, and 99.8%, respectively, relative to those of the cells treated with LPS alone. LRCC5314 also inhibited adipogenesis in differentiating preadipocytes (3T3-L1 cells), showing a 14.7% decrease in lipid droplet levels and a 74.0% decrease in triglyceride levels, as well as distinct reductions in the mRNA expression levels of adiponectin, FAS, PPAR/γ, C/EBPα, TNF-α, and IL-6. Moreover, LRCC5314 reduced the level of cortisol, a hormone with important effect on stress, by approximately 35.6% in H295R cells. L. plantarum LRCC5314 is identified as a new probiotic with excellent in vitro multifunctional properties. Subsequent in vivo studies may further demonstrate its potential as a functional food or pharmabiotic.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.44-50
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• 2015

The purpose of this study was to characterize the lactic acid bacteria found in makgeolli in terms of bacterial identity and gastric compatibility. Lactic acid bacteria were isolated from commercial raw makgeolli and separated into six strains that are resistant to gastric acidity and bile acid. These strains were identified by analysis of their 16S rDNA, as Lactobacillus plantarum BSM-2 and EHJ-1, Lactobacillus casei GSM-3 and EHJ-2, Lactobacillus brevis BSM-3 and Pediococcus pentosaceus TJH-1. All strains exhibited adhesion to intestines, showing that they were probiotic. We also found that L. plantarum BSM-2 had excellent resistance to bile acid as well as antioxidant activity. Taken together with its antibacterial properties and ability to lower cholesterol, our data suggest that L. plantarum BSM-2 was the most beneficial probiotic among the six strains.

• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.307-314
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• 2006

To search direct fed microbials, we isolated a Candida sp. from kefir grain. The isolated Candida sp. strain showed 99.8% of identity to the species of Candida kefyr by API 20C kit. Enzyme activity of Candida kefyr was higher in amylase (0.33±1.12μmol/min/mg) than that in phytase (0.052±0.98μmol/ min/mg) cellulase(0.051±μmol/min/mg) and xylanase (0.011±0.98mol/min/mg). The maximum numbers of Candida kefyr in growth curve were reached at 30 h fermentation. Candida kefyr showed high resistances to acidic environment, which was not perfectly extincted even at pH 2.0. And it showed high tolerance to bile salt which had almost 97.2% of survival in the presence of 1.0% bile salt.Especially, Candida kefyr showed high heat stability which remained 10% of initial microorganisms at 60℃. Candida kefyr was not generally inhibited by most of 11 antibiotic agent which contained tetracycline groups. These results suggest that the isolated Candida kefyr has a useful properties as probiotics.