• Journal of Microbiology and Biotechnology
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• 제34권4호
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• pp.871-879
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• 2024

Our group had isolated Bifidobacterium breve strain BS2-PB3 from human breast milk. In this study, we sequenced the whole genome of B. breve BS2-PB3, and with a focus on its safety profile, various probiotic characteristics (presence of antibiotic resistance genes, virulence factors, and mobile elements) were then determined through bioinformatic analyses. The antibiotic resistance profile of B. breve BS2-PB3 was also evaluated. The whole genome of B. breve BS2-PB3 consisted of 2,268,931 base pairs with a G-C content of 58.89% and 2,108 coding regions. The average nucleotide identity and whole-genome phylogenetic analyses supported the classification of B. breve BS2-PB3. According to our in silico assessment, B. breve BS2-PB3 possesses antioxidant and immunomodulation properties in addition to various genes related to the probiotic properties of heat, cold, and acid stress, bile tolerance, and adhesion. Antibiotic susceptibility was evaluated using the Kirby-Bauer disk-diffusion test, in which the minimum inhibitory concentrations for selected antibiotics were subsequently tested using the Epsilometer test. B. breve BS2-PB3 only exhibited selected resistance phenotypes, i.e., to mupirocin (minimum inhibitory concentration/MIC >1,024 ㎍/ml), sulfamethoxazole (MIC>1,024 ㎍/ml), and oxacillin (MIC >3 ㎍/ml). The resistance genes against those antibiotics, i.e., ileS, mupB, sul4, mecC and ramA, were detected within its genome as well. While no virulence factor was detected, four insertion sequences were identified within the genome but were located away from the identified antibiotic resistance genes. In conclusion, B. breve BS2-PB3 demonstrated a sufficient safety profile, making it a promising candidate for further development as a potential functional food.

• 생명과학회지
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• 제27권11호
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• pp.1290-1298
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• 2017

인체의 장내에 존재하는 장내 미생물은 서로 공생 또는 길항 관계를 유지하며 우리 몸의 면역 방어 기전에 중요한 요소로 작용한다. 본 연구는 항암제가 위암 환자의 장내 미생물 생태계에 미치는 영향을 조사 하였다. 항암치료를 받는 환자의 분변에서 genomic DNA를 추출하고, 16S rDNA 유전자에 대한 denaturing gradient gel electrophoresis (DGGE)를 수행하였다. 분석된 균주는 개체간의 차이가 있었으나, 대부분 사람의 장내에 살고 있는 normal flora로 동정되었다. 모든 분변에 존재하는 5 개 밴드의 서열 분석 결과에 의하면 Faecalibacterium prausnitzii, Morganella morganii 및 Uncultured bacterium sp.가 나타났고, 항암제 처리 후 Sphingomonas paucimobilis, Lactobacillus gasseri, Parabacteroides distasonis 및 Enterobacter sp.가 증가하였다. 이 연구에서 probiotic으로 알려진 Bifidobacterium과 Lactobacillus를 특이적 PCR primer를 이용하여 동정한 결과, 항암제 투여로 인해 Bifidobacterium과 Lactobacillus의 개체군이 현저하게 줄어들어 diarrhea와 같은 부작용의 원인을 예상하게 하며, 장내 생태계의 주요 박테리아 집단에도 중요한 영향을 미치는 것을 알 수 있었다. 이러한 결과는 항암제 투여와 같이 시간의 흐름에 따른 균총의 변화를 시각적으로 모니터링하기 위하여 PCR-DGGE 분석법이 유용하다는 것을 나타낸다.

• Journal of Microbiology
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• 제45권4호
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• pp.305-310
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• 2007

The principal objective of this study was to compare the effects of whole and hydrolyzed cells (bifidobacteria) treated with gastrointestinal digestive enzymes on the activation of cloned macrophages. Seven different strains of Bifidobacterium obtained from swine, chickens, and rats, were digested with pepsin followed by pancreatin and the precipitate (insoluble fraction) and supernatant (soluble fraction) obtained via centrifugation. The RAW 264.7 murine macrophages were incubated with either whole cells, the precipitate, or supernatant at various concentrations. Pronounced increases in the levels of nitric oxide (NO), interleukin $(IL)-1{\beta}$, IL-6, IL-12, and tumor necrosis factor $(TNF)-{\alpha}$ were observed in the whole cells and precipitates, but these effects were less profound in the supernatants. The precipitates also evidenced a slight, but significant, inductive activity for NO and all tested cytokines, with the exception of $(TNF)-{\alpha}$ in the macrophage model as compared with the whole cells. By way of contrast, $(TNF)-{\alpha}$ production when cultured with whole cells (100 ng/ml) resulted in marked increases as compared with what was observed with the precipitates. The results of this study indicated, for the first time, that digested Bifidobacterium sp. can induce the production of NO and several cytokines in RAW 264.7 murine macrophage cells. In the current study, it was demonstrated that Bifidobacterium strains treated with digestive enzymes, as compared with whole cells, are capable of stimulating the induction of macrophage mediators, which reflects that they may be able to modulate the gastrointestinal immune functions of the host.

• Preventive Nutrition and Food Science
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• 제14권3호
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• pp.265-268
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• 2009

Three-hundred bacterial isolates from a natural cheese were screened for the production of bifidobacterial growth factor by whey fermentation. Based on this screen, two whey samples fermented by strains designated as CJNU 0421 and CJNU 0588 were found to effectively stimulate the growth of a bifidobacterial strain, Bifidobacterium longum FI10564, by 1.6$\sim$1.7 fold compared to a control, in which non-fermented whey medium was added. The two isolates were identified to be Lactobacillus casei (99% identity) by 16S rRNA gene sequencing and named Lactobacillus casei CJNU 0421 and CJNU 0588, respectively. The whey sample fermented by CJNU 0588 did not enhance the growth of other bacteria such as Escherichia coli and Listeria monocytogenes, suggesting that the whey fermentation metabolites from the isolate could be used for the selective stimulation of bifidobacteria.

• Journal of Microbiology and Biotechnology
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• 제20권6호
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• pp.1022-1026
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• 2010

The different cleavage patterns of pYBamy59 plasmid isolated from E. coli $DH5{\alpha}$ and B. longum MG1 by the cell extract of B. longum MG1 suggested that the main reason for its low transformation efficiency was related to the restriction modification (R-M) system. To confirm the correlation between the R-M system and transformation efficiency, in vitro methylation and site-directed mutagenesis were performed in pYBamy59. Sequence analysis of pYBamy59 fragments digested by the cell extract of B. longum MG1 revealed that all fragments were generated by restriction of the sequence recognized by SacII endonuclease. When pYBamy59 from E. coli was methylated in vitro by CpG or GpC methyltransferase, it was protected from SacII digestion. Site-directed mutagenesis, which removed SacII sites from pYBamy59, or in vitro methylation of pYBamy59 showed 8- to 15-fold increases in the transformation efficiency over intact pYBamy59. Modification of the SacII-related R-M system in B. longum MG1 and in vitro methylation in pYBamy 59 can improve the transformation efficiency in this strain. The results showed that the R-M system is a factor to limit introduction of exogenous DNA, and in vitro modification is a convenient method to overcome the barrier of the R-M system for transformation.

• Journal of Microbiology and Biotechnology
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• 제16권5호
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• pp.661-666
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• 2006

The present study represents the investigation of in vitro immunopotentiating activities of cellular fractions of major lactic acid bacteria found in kimchi (KLAB) and bifidobacteria. The macrophage cells, RAW264.7, were stimulated with heat-killed whole-cell, cell-wall, and cytoplasmic fractions of four strains of KLAB (Leuconostoc mesenteroides, Leuconostoc citreum, Lactobacillus plantarum, and Lactobacillus sake) and two strains of bifidobacteria (Bifidobacterium longum and Bifidobacterium lactis) each, and then the production of nitric oxide (NO) and cytokines including tumor necrosis $factor-\alpha\;(TNF-\alpha)$ and interleukin-6 (IL-6) was measured by Griess and ELISA assays, respectively. Heat-killed wholecell and cell-wall fractions-but not the cytoplasmic fraction-from all strains of KLAB significantly increased the production of NO in RAW264.7 cells, and all fractions from bifidobacteria exerted similar effects. In the production of $TNF-\alpha$, heat-killed whole-cell and cell-wall fractions of L. plantarum showed the strongest effect, followed by L. sake and B. lactis, whereas other KLAB fractions did not exert any effect. In the production of IL-6, only whole-cell and cell-wall fractions of L. plantarum were effective. These results, taken together, indicate that L. plantarum might playa critical role in the immunopotentiating activities of kimchi.

• Journal of Microbiology and Biotechnology
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• 제28권11호
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• pp.1800-1805
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• 2018

Inflammatory bowel disease, including Crohn's disease and ulcerative colitis (UC), is a chronically relapsing inflammatory disorder of the gastrointestinal tract. Intestinal epithelial cells (IECs) constitute barrier surfaces and play a critical role in maintaining gut health. Dysregulated immune responses and destruction of IECs disrupt intestinal balance. Dextran sodium sulfate (DSS) is the most widely used chemical for inducing colitis in animals, and its treatment induces colonic inflammation, acute diarrhea, and shortening of the intestine, with clinical and histological similarity to human UC. Current treatments for this inflammatory disorder have poor tolerability and insufficient therapeutic efficacy, and thus, alternative therapeutic approaches are required. Recently, dietary supplements with probiotics have emerged as promising interventions by alleviating disturbances in the indigenous microflora in UC. Thus, we hypothesized that the probiotic Bifidobacterium animalis subsp. lactis strain BB12 could protect against the development of colitis in a DSS-induced mouse model of UC. In the present study, oral administration of BB12 markedly ameliorated DSS-induced colitis, accompanied by reduced tumor necrosis factor-${\alpha}$-mediated IEC apoptosis. These findings indicate that the probiotic strain BB12 can alleviate DSS-induced colitis and suggest a novel mechanism of communication between probiotic microorganisms and intestinal epithelia, which increases intestinal cell survival by modulating pro-apoptotic cytokine expression.

• 한국식품과학회지
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• 제28권5호
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• pp.947-952
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• 1996

버섯이 유산균 증식 효과를 측정한 결과 대부분의 버섯이 B. breve에 대한 증식 효과와 배양배지의 pH 저하 효과가 우수했으며 식용버섯 중에서는 표고버섯, 운지버섯, 영지버섯, 느타리버섯이 우수했다. 사람 및 흰쥐의 장내 세균을 버섯추출물 함유 배지에서 배양시 배지의 pH 저하 효과가 우수한 표고버섯, 운지버섯, 양송이버섯은 장내유산균을 선택적으로 증식시켰다. B. breve 배양시 버섯추출물의 첨가는 균의 성장을 촉진하였으며 ${\beta}-glucosidase$의 효소 활성을 억제하였으며, 이는 배양배지의 pH 저하 효과와 비례하였다. 표고버섯, 영지버섯, 운지버섯은 사람 및 흰쥐의 장내 세균총 효소인 ${\beta}-glucosidase$ 및 tryptophanase 효소 활성을 억제하였으며 pH 저하 효과와 비례하였다.

• 대한수의학회지
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• 제55권2호
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• pp.81-88
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• 2015

This study was conducted to isolate lactic acid bacteria (LAB) from dog intestine and identify potential probiotic strains for canine use. One hundred and one LAB were isolated from feces of 20 healthy dogs. Acid, bile, and heat resistance along with adherence to Caco-2 cells and antimicrobial activity against pathogens were examined. To analyze immunomodulative effects, the production of nitric oxide (NO), TNF-${\alpha}$, and IL-$1{\beta}$ was measured using RAW 264.7 macrophages. Additionally, RAW BLUE cells were used to evaluate nuclear factor-${\kappa}B$ (NF-${\kappa}B$) generation. Ultimately, three strains were selected as canine probiotics and identified as Lactobacillus reuteri L10, Enterococcus faecium S33, and Bifidobacterium longum B3 by 16S rRNA sequence analysis. The L10 and S33 strains showed tolerance to pH 2.5 for 2 h, 1.0% Oxgall for 2 h, and $60^{\circ}C$ for 5 min. These strains also had strong antimicrobial activity against Escherichia coli KCTC 1682, Salmonella Enteritidis KCCM 12021, Staphylococcus aureus KCTC 1621, and Listeria monocytogenes KCTC 3569. All three strains exerted better immunomodulatory effects than Lactobacillus rhamnosus GG (LGG), a well-known commercial immunomodulatory strain, based on NO, NF-${\kappa}B$, IL-$1{\beta}$, and TNF-${\alpha}$ production. These results suggested that the three selected strains could serve as canine probiotics.

• Applied Biological Chemistry
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• 제40권2호
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• pp.167-171
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• 1997

26종 콩과식물 종실의 메탄올 조추출물의 Bifidobacterium adolescentis, B. longun, B. bifidum, Lactobacillus casei에 대한 생육촉진 및 생육억제 활성을 탄소원 배지와 비탄소원 배지를 이용하여 in vitro 혐기조건하에서 각각 분광학적 및 여지확산법으로 검정한 결과 생육반응은 공시세균과 콩의 종류에 따라 달리 나타났다. 콩과식물 종실중, 대두(밝은 청색 종실)와 땅콩 (짙은 갈색 종실) 추출물은 유산균의 생육을 촉진하였는데, 이러한 결과로 부터 이들 콩과식물 종실에 탄소원과 비탄소원의 비피더스 인자의 존재를 알 수 있었다. 공시 유산균 중에서 L. casei에서 가장 현저한 생육측진 반응을 나타내었다. 또한, 모든 콩과식물 종실시료는 상기 유산균의 생육을 저해하지 않았다.