• Title/Summary/Keyword: Lactococcus

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Effect of Citrus Fermented by Lactococcus lactis W-44 Isolated from Kimchi on Growth of Cultured Flounder, Paralichthys olivaceus (김치에서 분리한 Lactococcus lactis W-44에 의한 감귤발효물의 양식 넙치 성장에 미치는 영향)

  • Kim, Min-Soo;Moon, Sang-Wook;Lee, Young-Don;Kim, Se-Jae;Kim, Yeong-Jin;Lee, Jun-Won;Lee, Jeong-Hee;Lee, Jung-Sook;Kim, Bo-Yeon;Ahn, Jong-Seog;Ahn, Soon-Cheol
    • Korean Journal of Microbiology
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    • v.43 no.2
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    • pp.124-129
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    • 2007
  • We evaluated the use of citrus fruit fermented by lactic acid bacteria, as a feed supplement for flounder (Paralichthys olivaceus) cultivation. For the fermentation, a lactic acid bacterial strain W-44 showing antibacterial activity was isolated from kimchi. From the phylogenetic analysis based on, 16S rDNA sequence, the strain W-44 was identified as Lactococcus lactis. After the fermentation of citrus fruit with L. lactis W-44, the contents of naringenin and hesperetin, bioactive flavonoid aglycones, were increased about ten-fold and six-fold, respectively. The effects of fermented citrus fruit-based feed additives (CFBFA) were tested on the growth of flounder, Paralichthys olivaceus. There were significant differences in average total length and body weight between the experimental and control group. The growth rate of the experimental group fed with the 0.2% CFBFA-supplemented diet was increased 4.5% and 20.9% more than the control group in total length and body weight, respectively. These results suggest that the fermented citrus fruit could be used as a functional feed additive for flounder cultivation.

Double-culture Method Enhances the in Vitro Inhibition of Atopy-inducing Factors by Lactococcus lactis (이중배양법에 따른 Lactococcus lactis의 아토피 유발인자 억제 효과 증대)

  • Jo, Yu Ran;Kang, Sang Mo;Kim, Hyun Pyo
    • Journal of Life Science
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    • v.25 no.7
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    • pp.810-818
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    • 2015
  • We analyzed whether lactic acid bacteria could control the expression of IL-4 and IL-13 in activated mast cells and whether these bacteria could inhibit the activity of transcription factors such as GATA-1, GATA-2, NF-AT1, NF-AT2, and NF-κB p65. We previously described a technique for identification of lactic acid bacteria with anti-atopy functionality by confirming increased expression of CD4+/CD25+/foxp3+ in T cells. We also confirmed that a double-culture method increased the antibacterial activity of these lactic acid bacteria against Staphylococcus aureus (S. aureus). In the present study, we characterized the effect of lactic acid bacteria cultured by this double-culture method on inhibition of allergic inflammatory reactions of RBL-2H3 mast cells, a cellular model of atopic dermatitis. The strongest anti-allergic effects of the lactic acid bacteria were seen in the following order: Lactococcus lactis broth cultured with medium containing Lactobacillus plantarum culture supernatant > Lc. lactis > Lc. lactis broth cultured with medium containing Lb. plantarum culture supernatant > Lb. plantarum. Thus, Lc. lactis cultured in medium containing Lb. plantarum culture supernatant had the strongest inhibitory effect on the differentiation of mast cells during allergic reactions, which may be mediated through the selective regulation of expression of relevant genes.

Distribution and Biodiversity of Lactic Acid Bacteria Having Bacteriocin-like Activity from Fresh Fruits and Vegetables (신선 과채류에 존재하는 박테리오신 유사 활성을 지니는 유산균의 분포와 다양성)

  • Park, Young-Seo;Jang, Jae Kweon;Choi, Young Jin;Chung, Myong-Soo;Park, Hoon;Shim, Kun-Sub
    • Food Engineering Progress
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    • v.13 no.1
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    • pp.64-69
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    • 2009
  • From the 25 fresh fruits and vegetable products, 1,250 isolates grown on MRS agar media were screened for the inhibitory activity on the growth of Escherichia coli 0157:H7, Listeria monocytogenes, and Bacillus cereus as well as Lactobacillus plantarum, L. casei, and Lactococcus lactis subsp. lactis. Among them, 607 isolates (49% of total isolates) from 23 different foods produced growth inhibitory activity on the E. coli 0157:H7, L. monocytogenes, or B. cereus. When these isolates were screened for the inhibitory activity on the growth of L. plantarum, L. casei, and Lactococcus lactis subsp., 24 isolates (3% of total isolates) from 7 food samples showed bacteriocin-like activity. These isolates had typical physiological characteristics of lactic acid bacteria, which indicated these isolates were strains of lactic acid bacteria. The inhibitor from 3 out of 24 revealed as nicin. From the RAPD-PCR profiles, 24 strains was classified and it was also indicated that most of the strains isolated from same produce showed similar phylogenetic profile.

Cloning of the Entire Gene Encoding the 140-kDa $\alpha$-Amylase of Lactobacillus amylovorus and Expression in Escherichia coli and Lactococcus lactis

  • Jeong, Jong-Jin;Kim, Tea-Youn;Kim, Jeong-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.7 no.5
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    • pp.293-298
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    • 1997
  • A 4.6-kb HindIII fragment encompassing the complete 140-kDa ${\alpha}$-amylase gene of Lactobacillus amylovorus B 4540 was cloned into pBR322 by the shot gun method. Southern blotting and restriction mapping for the insert were performed. The recombinant 9.0-kb plasmid, pFML1, conferred ${\alpha}$-amylase activity to E. coli and Lactococcus lactis hosts when introduced by electroporation. SDS-PAGE and zymography confirmed the production of 140-kDa ${\alpha}$-amylase and its proteolytic degradation products with enzyme activity in transformants. Total ${\alpha}$-amylase activity of E. coli $DH5{\alpha}$ cells harboring pFML1 was 1.8 units and most activity was detected from cell pellets. Total enzyme activity of L. lactis subsp. lactis MG1363 transformant was five to ten-fold lower than that of E. coli cell but more than half of the activity was detected in the culture supernatant.

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