• 한국축산식품학회지
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• 제25권4호
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• pp.494-499
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• 2005

본 연구에서는 유아의 분변에서 분리한 항산화 효과를 갖는 유산균인 Lactobacillus gasseri KACC 91155의 Jurkat T cell line에서의 지질 과산화 억제 효과, 세포 보호 효과 및 DNA 손상 억제 효과를 측정하였다. 그 결과 1. gasseri 91155는 세포 산화에 의해 생성된 지질 과산화물인 MDA의 생성을 방지하였으며, 또한 뚜렷하게 세포 생존성을 증가시켰다. 그리고 산화적 손상으로부터 DNA 손상을 줄여주는 효과를 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제31권9호
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• pp.1281-1287
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• 2021

Clinical and preclinical studies have reported that Lactobacillus gasseri BNR17, a probiotic bacterial strain isolated from human breast milk, reduces body weight and white adipose tissue volume. In order to further explore the actions of L. gasseri BNR17, we investigated the anti-menopausal effects of L. gasseri BNR17 in an ovariectomized (OVX) rat model. The serum alanine aminotransferase levels of the rats in the OVX-BNR17 group were lower than those of the rats in the OVX-vehicle only (OVX-Veh) group. Upon administration of L. gasseri BNR17 after ovariectomy, calcitonin and Serotonin 2A levels increased significantly, whereas serum osteocalcin levels showed a decreasing tendency. Compared to the rats in the OVX-Veh group, those in the OVX-BNR17 group showed lower urine deoxypyridinoline levels, lower pain sensitivity, and improved vaginal cornification. Furthermore, L. gasseri BNR17 administration increased bone mineral density in the rats with OVX-induced femoral bone loss. These results suggest that L. gasseri BNR17 administration could alleviate menopausal symptoms, indicating that this bacterium could be a good functional probiotic for managing the health of older women.

• Journal of Dairy Science and Biotechnology
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• 제36권1호
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• pp.39-48
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• 2018

This study examined the immunomodulatory effects of milk fermented with based on the synbiotic interaction between Cudrania tricuspidata leaf extract (CT) and Lactobacillus gasseri 505. Raw 264.7 macrophages were treated with milk (Control), milk supplemented with 0.2% CT (CT-milk), or CT-milk fermented with L. gasseri 505 (FCT). FCT-treated cells showed higher NO production than the other groups. ELISA revealed that FCT produced the highest enhancement of the production of pro-inflammatory cytokines such as $TNF-{\alpha}$, $IFN-{\gamma}$, $IL-1{\beta}$, IL-6, IL-2, IL-12, and IL-10. Furthermore, FCT also increased the gene expression of pro-inflammatory mediators such as iNOS and COX-2 in a concentration-dependent manner. Collectively, these results indicate that the synbiotic interaction between CT and L. gasseri 505 might enhance their immunomodulatory effects of fermented milk.

• Asian-Australasian Journal of Animal Sciences
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• 제19권9호
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• pp.1335-1341
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• 2006

We selected a Lactobacillus spp. from Korean healthy infant feces based upon their antioxidant activity. This strain was identified as Lactobacillus gasseri by 16S rDNA sequencing, and named Lactobacillus gasseri NLRI-312. In the present study, we investigate the protective effect of this strain on the $H_2O_2$ induced damage to cellular membrane lipid and DNA in Jurkat cells. To estimate the extent of cellular lipid peroxidation inhibition, MDA (malondialdehyde) was measured, and DNA damage was tested by the comet assay. We also examined probiotic properties including tolerance to acid and bile, antibiotic resistance. From the results obtained, the supplementation of Jurkat cells with NLRI-312 decreased in DNA damage, while no effect was shown on MDA decrease. In probiotic properties, this strain was resistance to both acid and bile, showed considerably higher survival when incubated in pH 2 or 1% bile salts (w/v). We concluded that the NLRI-312 could be used as potential probiotic bacteria, with the effect of reducing DNA damage induced by $H_2O_2$.

• 한국미생물·생명공학회지
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• 제49권1호
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• pp.1-8
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• 2021

Human breast milk is a potential source of bacteria for the development of the intestinal microbiota of infants. Several species within the genera Lactobacillus and Bifidobacterium were demonstrated to shape the gut microbiota of infants. In this study, the bacterial diversity was investigated in the breast milk and feces of a mother-infant pair, and probiotic candidates were identified. Importantly, the novel L. gasseri EJL and B. breve JTL strains were isolated from breast milk and infant feces samples, respectively; their completed genome was resolved using de novo sequencing. In addition, the bacterial composition in the infant's feces at 1 week revealed the prevalence of Bifidobacterium and Streptococcus; a higher diversity was observed after 3 weeks. In particular, the abundance of Akkermansia was sharply increased at 7 weeks, further increasing thereafter, up to 15 weeks. Our results suggest that human breast milk and infant's feces are a source of probiotic candidates.

• Journal of Microbiology
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• 제39권2호
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• pp.146-148
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• 2001

Lactobacillus crispatus ATCC 33820 and L. gasseri ATCC 33323 were grown in MRS broth (pH 6.5) at 37$^{\circ}C$ for 24 h and the antibacterial activities of cell free culture supernatants were determined by the agar well diffusion method. The culture supernatants were inhibitory to Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Enterococcus faecalis, Pediococcus acidilacticii, and Lactobacillus helveticus. The supernatants did not show any lysozyme activity. Addition of catalase did not affect the antibacterial activities of the supernatants. The antibacterial substances were heat stable (100$^{\circ}C$ for 60 min) and sensitive to proteases.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.202-205
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• 2000

A gene coding $endo-{\beta}$,-1, 4 glucanase from Actinomyces sp. KNG40 and phytase from Hansenula polymorpha were cloned into Esherichia coli JM101 by using E. coli/Lactobacillus shuttle vector pNZ3004 and pNZ123. The plasmid p3PS(1-4) and p123(1-4) have slpA promoter and slpA signal sequence. So, I constructed expression vectors, p3PS(1-4)Endo, phy and p123(1-4)Endo, phy. These constructed vector was transformed in target host Lactobacillus gasseri and reutri. These transformed host expressed endoglucanase and phytase as extracellular fraction. In the enzyme activity of the same vector, host L, gasseri was higher activity than L. reuteri. This indicates that L. gasseri recongnize promoter and signal sequence very well.

• Animal Bioscience
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• 제34권9호
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• pp.1525-1531
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• 2021

Objective: The objective of this study was to evaluate the antimicrobial effects of fermented Maillard reaction products made by milk proteins (FMRPs) on Clostridium perfringens (C. perfringens), and to elucidate antimicrobial modes of FMRPs on the bacteria, using physiological and morphological analyses. Methods: Antimicrobial effects of FMRPs (whey protein plus galactose fermented by Lactobacillus rhamnosus [L. rhamnosus] 4B15 [Gal-4B15] or Lactobacillus gasseri 4M13 [Gal-4M13], and whey protein plus glucose fermented by L. rhamnosus 4B15 [Glc-4B15] or L. gasseri 4M13 [Glc-4M13]) on C. perfringens were tested by examining growth responses of the pathogen. Iron chelation activity analysis, propidium iodide uptake assay, and morphological analysis with field emission scanning electron microscope (FE-SEM) were conducted to elucidate the modes of antimicrobial activities of FMRPs. Results: When C. perfringens were exposed to the FMRPs, C. perfringens cell counts were decreased (p<0.05) by the all tested FMRPs; iron chelation activities by FMRPs, except for Glc-4M13. Propidium iodide uptake assay indicate that bacterial cellular damage increased in all FMRPs-treated C. perfringens, and it was observed by FE-SEM. Conclusion: These results indicate that the FMRPs can destroy C. perfringens by iron chelation and cell membrane damage. Thus, it could be used in dairy products, and controlling intestinal C. perfringens.

• 한국미생물·생명공학회지
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• 제17권2호
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• pp.94-99
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• 1989

1. L. acidophilus 균주에 작용하는 bacteriocin을 생산하는 Lactobacillus속 균 7주를 발견하였다. bacteriocin 생산균주는 1주가 L. gasseri였고, 그 외에는 모두 L. acidophilus였다. 2. 조사한 bacteriocin생산 6균주 중 5균주는 대수발육 중기 혹은 후기 내지 정상기의 초기에 최대의 bacteriocin 활성을 나타내었으나, 그 후 급격히 활성이 감소하였다. 3. 이들의 bacteriocin은 단백분해효소 처리로 용이하게 실활하는 단백질성임을 나타내었으나, 핵산분해 효소에는 저항성이었다. 또 이들의 bacteriocin은 지금 까지 보고되고 있는 Lactobacillus속의 bacteriocin과 다르며, 정도의 차는 있으나 전부 10$0^{\circ}C$ 가열에 감수성이 있었다. 4. L. acidophilus ATCC 9857 및 L. acidophilus ATCC 4357이 생산하는 bacteriocin은 diethylether 처리에 활성이 감소하므로 지질을 함유함을 시사하였다. 5. L. acidophilus A4가 생산하는 bacteriocin은 지시균의 세포벽 외층의 규칙적 배열구조에 흡착함을 시사하였다. 또 L. acidophilus ATCC 4355가 생산하는 bacteriocin은 지시균의 세포벽에는 흡착하지 않음을 알 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제17권9호
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• pp.1521-1526
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• 2007

A maltogenic amylase gene from Lactobacillus gasseri ATCC33323 (LGMA) was expressed in Lactococcus lactis MG1363 using the P170 expression system. The successful production of recombinant LGMA (rLGMA) was confirmed by the catalytic activity of the enzyme in liquid and solid media. The N-terminal amino acid sequencing analysis of the rLGMA showed that it was Met-Gln-Leu-Ala-Ala-Leu-, which was the same as that of genuine protein, meaning the signal peptide was efficiently cleaved during secretion to the extracellular milieu. The optimal reaction temperature and pH of rLGMA ($55^{\circ}C$ and pH 5, respectively) and enzymatic hydrolysis patterns on various substrates (${\beta}$-cyclodextrin, starch, and pullulan) supported that rLGMA was not only efficiently secreted from the Lactococcus lactis MG1363 but was also functionally active. Finally, the branched maltooligosaccharides were effectively produced from liquefied com starch, by using rLGMA secreted from Lactococcus lactis, with a yield of 53.1%.