• Journal of Microbiology and Biotechnology
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• v.25 no.11
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• pp.1849-1855
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• 2015

Staphylococcus aureus plays an important role in sepsis, septic shock, pneumonia, and wound infections. Here, we demonstrate that Lactobacillus plantarum extracts inhibited S. aureus-induced cell death of a human epithelial cell line, HT-29. In particular, we have shown that S. aureus-induced cell death was abolished by neutralization of α-toxin, indicating that α-toxin is the major mediator of S. aureus-induced cell death. DNA fragmentation experiment and caspase assay revealed that the S. aureus-induced cell death was apoptosis. L. plantarum extracts inhibited the generation of effector caspase-3 and the initiator caspase-9 in S. aureus- or α-toxin-induced cell death. Moreover, expression of Bcl-2, an anti-apoptotic protein, was activated in L. plantarum extract-treated cells as compared with the S. aureus- or α-toxin-treated only cells. Furthermore, S. aureus-induced apoptosis was efficiently inhibited by lipoteichoic acid and peptidoglycan of L. plantarum. Together, our results suggest that L. plantarum extracts can inhibit the S. aureus-mediated apoptosis, which is associated with S. aureus spreading, in intestinal epithelial cells, and may provide a new therapeutic reagent to treat bacterial infections.

• Journal of Microbiology and Biotechnology
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• v.31 no.5
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• pp.726-732
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• 2021

In this study, we evaluated the immune-enhancing activity of kimchi-derived Lactobacillus plantarum 200655 on immune suppression by cyclophosphamide (CP) in ICR mice. Animals were fed distilled water or 1×10⁹ colony-forming unit/kg B.W. 200655 or Lactobacillus rhamnosus GG as a positive control for 14 days. An in vivo model of immunosuppression was induced using CP 150 and 100 mg/kg B.W. at 7 and 10 days, respectively. Body weight, spleen index, spleen weight, and gene expression were measured to estimate the immune-enhancing effects. The dead 200655 (D-200655) group showed an increased spleen weight compared to the sham control (SC) group. Similarly, the spleen index was significantly higher than that in the CP-treated group. The live 200655 (L-200655) group showed an increased mRNA expression of tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6 in splenocytes. Also, the iNOS and COX-2 mRNA expression was upregulated in the L-200655 group compared to the CP-only (SC) group. The phosphorylation of ERK and MAPK was also upmodulated in the L-200655 group. These results indicate that L. plantarum 200655 ameliorated CP-induced immune suppression, suggesting that L. plantarum 200655 may have the potential to enhance the immune system.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.655-658
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• 2011

The possible application of Lactobacillus spp. as a functional starter culture to ferment galgeuntang (GT) and to produce bioactive isoflavone (daidzein) was investigated. Lactobacillus casei KFRI 127, L. plantarum KFRI 144, L. bulgaricus KFRI 344 were used for GT fermentation. Acid development and quantification of isoflavones using high-performance liquid chromatography were performed after fermentation at 37$^{\circ}C$ for 48 h. All the tested Lactobacillus spp. lowered pH to about 3.8 in 48 h and L. plantarum KFRI 144 exhibited 89.9% hydrolysis rate of daidzin (79.1-8.0 ${\mu}g$/mL) during fermentation. The content of daidzein in GT fermented with L. plantarum KFRI 144 was increased by 6.6-fold (3.6-23.9 ${\mu}g/mL$). These results demonstrate that L. plantarum KFRI 144 has potential as functional starter culture for manufacturing fermented GT with higher isoflavone bioavailability.

• Korean Journal of Microbiology
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• v.39 no.3
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• pp.192-196
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• 2003

To obtain large pools of lactic acid bacteria, a strain was isolated from Tongchimi. Through its sugar fermentation and analysis of 16S rRNA gene, it was identified to be Lactobacillus plantarum HB1. This strain is Gram-positive and catalase-negative. In the range of 1～88 bp in the HB1 16S rRNA gene, the HB1 strain was homologous with other L. plantarum strains by almost 100%, and in the range of the rest 32 bp, the HB1 strain showed considerable variation, compared to other strains. Nitrate which may exist in radish can be easily converted to nitrite. The nitrite interacts with amine, and becomes nitrosamine which may cause stomach cancer. The culture obtained by HB1 strain could eliminate 400 ${\mu}M$ nitrite within 1.5 hr. It is necessary to isolate specific components which are involved in nitrite elimination in the culture and to study on its mechanism.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.328-335
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• 2010

The aim of our study was to develop a new starter culture for fermented milk. Polymerase chain reaction screening of 103 acid-producing isolates from Kimchi identified 72 Lactobacillus strains. The ability of the strains to inhibit the growth of the food-borne human pathogens (Escherichia coli, Salmonella Enteritidis, Staphylococcus aureus) was measured, using a conventional paper disk method. Among the 72 strains, strain LHC52 displayed potent antagonistic activity. Use of 16S rDNA sequencing and the API 50CHL system identified the strain as Lactobacillus plantarum and it was designated L. plantarum LHC52. Biochemical analyses revealed especially high antibacterial activity against E. coli. Yogurt produced using L. plantarum LHC52 did not show different microbiological and physicochemical properties compared to conventionally-prepared yogurt, implicating L. plantarum LHC52 as a useful, potently antibacterial starter culture for yogurt preparation.

• Microbiology and Biotechnology Letters
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• v.36 no.4
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• pp.276-284
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• 2008

A lactic acid bacterium having antifungal activity was isolated from kimchi. It was identified as Lactobacillus plantarum based on its morphological and biochemical properties, and 16S rRNA sequence, and designated as Lb. plantarum AF1. This isolate inhibited the growth of Aspergillus flavus ATCC 22546, A. fumigatus ATCC 96918, A. petrakii PF-1, A. ochraceus PF-2, A. nidulans PF-3, Epicoccum nigrum KF-1, and Cladosporium gossypiicola KF-2 under a dual culture overlay assay. Also, the antimicrobial activity was found to be active against various species of Gram-positive and Gram-negative bacteria. The antifungal activity was found to be stable after heat ($121^{\circ}C$, 15 min) and proteolytic enzyme treatment, but it was unstable over pH 5.0. The antifungal compound(s) was estimated to have a low molecular mass (below 3,000 Da).

• Korean Journal of Food Science and Technology
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• v.41 no.4
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• pp.399-404
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• 2009

The goal of this study was to improve the quality of cheonggukjang by the optimization of the inoculation methods of the Bacillus subtilis (B. subtilis) and Lactobacillus plantarum (L. plantarum) strains. In order to optimize the mixed cultivation of B. subtilis and L. plantarum, the B. subtilis strain was inoculated into steamed soybeans after cultivation of L. plantarum. Inoculation size of B. subtilis was changed to the simultaneous inoculation method in order to stimulate the growth of the L. plantarum in cheonggukjang. The viable cell count of L. plantarum increased from $2{\times}10^7$ CFU/g to $2-6{\times}10^8$ CFU/g and B. subtilis grew to $9{\times}10^8$ CFU/g. These results showed that 2 strains were successfully able to grow in the steamed soybean for good quality of cheonggukjang by optimization of the inoculation methods. The sensory evaluation indicated that a favorable aroma and overall acceptance of cheonggukjang by the optimized mixed cultivation of B. subtilis and L. plantarum, which was relatively higher than those of cheonggukjang by single strain inoculation of B. subtilis.

• Korean Journal of Veterinary Research
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• v.40 no.2
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• pp.325-332
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• 2000

The growth characteristics and the cellular protein patterns of the Lactobacillus plantarum isolated and identified from oat silage were examined in order to confirm whether it will be used practically as probiotics or not. L plantarum was identified by morphological and biochemical tests including of final conforming by API 50CHL kit. The cultivation in MRS broth of the strain under the condition of different temperature, proved that they grew into $2.0{\times}10^{9}$ in $25^{\circ}C$, into $1.4{\times}10^{9}$ in $35^{\circ}C$ but they decreased into $4.5{\times}10^{5}$ growth in $45^{\circ}C$. The comparison of the growth by measurement of O.D600nm value after 24 hour cultivation between L plantarum and commercial probiotics, showed that the strain had a higher growth than commercial as 1.841 : 1.623. The measurement of it under bile acid's existence, indicated that this isolation was not influenced by bile acid and the tolerance was $3.2{\times}10^{9}$, $3.9{\times}10^{9}$ and $3.2{\times}10^{9}$, respectively, when each of 0%, 1%, and 2% oxigall existed. The examination of their antibiotics susceptibility by disk diffusion test, proved that L plantarum showed resistance against danofloxacin(5mcg), gentamycin(10mcg), kanamycin(30mcg), neomycin(30mcg) and streptomycin(10mcg). Based upon the test of the bacteriocin formation of this L plantarum, it was found out that the inhibition zone was not formed. In growth of L plantarum and E coli in nutrient broth, all E coli died out within 6 hours after cultures.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.882-885
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• 2001

The cells of Lactobacillus plantarum MY4 isolated from the human feces were treated for 24 h in artificial bile after incubation for 2 h in artificial gastric juice and final number of the strain was reached to around $3.1{\times}10^8$ CFU/ml. In test of API ZYM kit, ${\beta}$-glucuronidase or ${\beta}$-glucosidase were not produced by L. plantarum MY4. However, ${\beta}$-galactosidase were weakly produced by it, which they would be alleviated the lactose intolerance. L. plantarum MY4 were resistant to antibiotics such as nisin, tetracycline, streptomycin, rifamycin, doxycycline, roxithromycin, chloramphenicol, nystatin, erythromycin, ciprofloxacin and gentamycin. L. plantarum MY4 was affected by alcohol concentration up to 8%, but more than 16%, their growth was not affected significantly. L. plantarum MY4 was shown to inhibit the growth of Listeria monocytogenes ATCC 19111 completely within 24 h of incubation, which indicates its bactericidal nature. Thus, L plantarum MY4 show promise as a probiotic strain because of its characteristics.

• Food Science of Animal Resources
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• v.38 no.2
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• pp.240-250
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• 2018

This study was undertaken to find the optimum soy-peptone, glucose, yeast extract, and magnesium sulfate amounts for the maximum growth of Lactobacillus plantarum JNU 2116 and to assess the effects of these medium factors through the use of response surface methodology. A central composite design was used as the experimental design for the allocation of treatment combinations. In the analysis of the experiment, due to a significant lack of fit of the second-order polynomial regression model that was used at first, cubic terms were added to the model, and then two-way interaction terms were deleted from the model since they were found to be all statistically insignificant. A relative comparison among the four factors showed that the growth of L. plantarum JNU 2116 was affected strongly by yeast extract, moderately by glucose and peptone, and slightly by magnesium sulfate. The estimated optimum amounts of the medium factors for the growth of L. plantarum JNU 2116 are as follows: soy-peptone 0.213%, glucose 1.232%, yeast extract 1.97%, and magnesium sulfate 0.08%. These results may contribute to the production of L. plantarum L67 as a starter culture that may have potential application in yogurt and fermented meat products.