• Journal of Microbiology and Biotechnology
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• 제5권3호
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• pp.149-153
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• 1995

A simple and low-cost medium was developed for the growth of Bifidobacterium longum KFRI 977. Of three bifidobacterial strains, B. longum KFRI 977 (ATCC 15707) showed the best growth in MRSC broth containing 0.3% oxgall, grew well in partially anaerobic condition, exhibited highest $\beta$-galactosidase activity, and was inhibitory against Clostridium perfringens KFRI 434. Of three developed media, the population of B. longum KFRI 977 was highest (1.9$\times$$10^9$/ml) in ISP based medium. The composition of ISP based medium is ISP (5%), glucose (1%), L-cysteine HCI (0.05%), Trypticase peptone (0.5%), yeast extract (0.5%), $MgSO_4$ (0.05%), Tween-80 (0.1%), and phosphate buffer (pH 7.0). Hydrolysis of ISP by Protease A was unnecessary, and the use of phosphate buffer (pH 7.0) prevented the formation of protein precipitate. Associative culture of B. longum KFRI 977 with Lactobacillus acidophilus KFRI 233 was proven to be deleterous to the growth of B. longum KFRI 977.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.457-462
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• 2003

The complete nucleotide sequence of a plasmid, pMG1, isolated from Bifidobacterium longum MG1 has been determined. This plasmid, composed of 3,862 base pairs with 65.1% of G+C content. harbors two major open reading frames (ORF) encoding putative proteins of 29 kDa (ORF I) and 71 kDa (ORF II). ORF I showed relatively high amino acid sequence homology with replication proteins of other plasmids from Gr Im-positive and -negative bacteria. Upstream of ORF I, four sets of tandem repeat sequences resembling the iteron structure of related plasmids were found. S1 endonuclease treatment and Southern blot analysis revealed that pMG1 accumulates single-stranded DNA (ssDNA) intermediate, which indicate i the rolling circle replication (RCR) mechanism of this plasmid. Homology search indicated that ORF II encodes plasmid mobilization protein, and the presence of highly conserved oriT sequence in the upstream of this gene supported this assumption. RT-PCR showed that only ORF I is expressed in vivo. Based on these results, pMG 1 was exploited to construct a shuttle vector, pBES2. It was successfully transformed into Bifidobacterium and maintained stably.

• Journal of Applied Biological Chemistry
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• 제43권1호
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• pp.54-58
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• 2000

Methanol extracts of 27 Brazilian plant samples and 10 oriental medicinal plant samples (27 families), using spectrophotometric and paper disc agar diffusion methods under anaerobic conditions, were tested in vitro for their growth-inhibiting activities against Bifidobacterium longum, Bifidobacterium bifidum, Bifidobacterium adolescentis, Clostridium perfringens, and Bacteroides fragilis. The responses varied with bacterial strains, plant species, and tissues sampled. In a test with B. longum and B. bifidum(20 mg/disc), extracts of Acanthopanax sessilifolinus stem bark and Ampelozizyphus amazonicus leaves strongly inhibited the growth of B. longum, whereas other plant samples did not inhibit any intestinal bacteria tested. At 5 mg/disc, adding extracts of Aralia eleta, Euterpe oleracea, and Syzygium guineense to the media strongly inhibited the growth of C. perfringens and B. fragilis without growth inhibition of B. adolescentis, B. longum, and B. bifidum. Extracts of Jacaranda mimosifolia and Ulmus paraifolia significantly inhibited the growth of C. perfringens and B. fragilis as well as B. adolescentis. These results may be indications of at least one of the pharmacological actions of the five Brazilian plants but not oriental medicinal plants tested.

• 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.

• 한국미생물·생명공학회지
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• 제19권5호
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• pp.456-463
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• 1991

Bif. longum KCTC 3215에 의한 Beta-galactosidase의 최적생성조건은 탄소원으로 lactose 1.0, 초기 pH 7.0, 배양온도 $37^{\circ}C$ 및 배양시간 17시간 후였다. 이 효소는 protamine sulfate, ammonium sulfate, DEAE-Sephadex A-50 ion exchange chromatography 및 Sephadex G-150 gel filtration 등 4단계 정제과정을 거쳐 9.25배 정제되었다.

• Journal of Microbiology and Biotechnology
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• 제10권2호
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• pp.147-153
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• 2000

This study was conducted to compare probiotic activities and physiological functions of Bifidobacterium longum Mk-G7 with weveral commercial and type strains of bifidobacteria. bif. longum MK-G7 showed the highest acid tolerance against HCl and acetic acid, whereas bif. infantis Y-1 showed the lowest acid tolerance and more than 4 log cycles of viable cell count decreased due to acid injuty. Viable cell counts of bifidobacteria strains decreased more than 1.5 log cycles owing to oxygen toxicity, with the exception of Bif. longum MK-G7, Bif. infantis Y-2, Bif. longum Y-3, Bif. longum Y-6, and Bif. longum RD-13 showed the highest bile tolerance, whereas Bif. longum MK-G7 showed a medium level of bile tolerance. Only Bif. longum MK-G7 howed much higher antibiotic resistance against both tetracycline and penicillin-G in the MIC(minimum inhibitory concentration) level of 24.8 mg/I and 0.52mg/I, respectively. Bif longum Y-6, and Bif. bifidum ATCC 29539 showed more than 80% of anti-mutagenicity against NQO(4-nitroquinolinel-oxide). Since the production of cytokines such as $TNF(tumor necrosis factor)-{\alpha}$ and IL (interleukin)-6, and NO(nitric oxide) in the macrophage cell line Raw 264.7 cells increased as Bif. longum MK-G7 cell concentration increased, ti was suggested that Bif. longum MK-G7 is able to enhance immunopotentiating activity in vitro. When freeze-dred Bif. longum MK-G7 was administered to mice at the dose of 1,2,4, and 6 g/kg of body weight, all of the mice survived in all feeding groups, proving the GRAS(generally recognized as safe) status of Bif. longum MK-G7. When fermented milk containing Bif. longum MK-G7 was administered to human volunteers, viable cell count of total bifidobacteria and anaerobes in the feces increased up to 0.5 log cycles more than before the administration. In particular, Bif. logum MK-G7 ingibited the growth of Bacteroides at the level of 1.0-1.5 log cycles.

• 미생물학회지
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• 제40권1호
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• pp.37-42
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• 2004

현재 상업적으로 이용되고 있는 비피더스균인 Bifidobacterium lactis Bb-12, Bif. longum Bb-536 및 Bif. infantis Maeil-K9의 선택적 계수를 위한 선택배지 개발을 위하여 다양한 탄소원과 질소원 및 여러 항생제들에 대한 내성을 검토하였다. 탄소원의 경우 기본생육배지에 각각 15 g/L 수준으로 첨가하여 각균주의 생육성을 비교해 본 결과 amygdalin과 fructose가 가장 적합하였으며, 질소원의 경우 tryptone이 가장 적합한 것으로 나타났다. Amygdalin을 탄소원으로 이용한 경우 Bif. lactis Bb-12와 Bif. infantis Maeil-K9의 생육성이 우수하였으며, fructose를 이용한 경우 Bif. longum Bb-536의 생육성이 우수하였다. 항생제 내성 검토에 있어서는 doxycyclin을 1 mg/L 수준으로 첨가하는 것이 가장 적절하였으며, Bif. lactis Bb-12및 Bif. infantis Maeil-K9의 생육에는 전혀 영향을 주지 않았으나, Bif. longum Bb-536의 생육은 완전히 억제시켰다. 그리고 저 활성 균주에 대한 각 선택 배지의 검출능을 알아보기 위하여 각균주를 -$70^{\circ}C$, $4^{\circ}C$, $40^{\circ}C$에 2주간 보존 후 생균수를 측정한 결과 amygdalin을 탄소원으로 이용한 배지에서는 $40^{\circ}C$ 보존균주의 검출능이 낮았으나, fructose를 탄소원으로 이용한 배지와 doxycyclin을 첨가한 배지의 경우 그 선택성이 매우 우수하였다.

• Environmental Analysis Health and Toxicology
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• 제25권1호
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• pp.79-84
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• 2010

이 연구의 목적은 유산균(LAB)의 항스트레스 효과를 알아보기 위함이다. 본 실험에서는 ICR 마우스에게 구속 스트레스를 가하면서 혼합유산균과 홍삼추출물을 경구투여 하였다. 5일간 Normal 그룹을 제외한 saline (control), LAB100, LAB200, RGE200에게 구속 스트레스를 주었다. 구속 스트레스를 가한 후에 ICR 마우스에게 kg당 100 mg ($3.0\times10^{11}$ CFU/g) 또는 200 mg $3.0\times10^{11}$ CFU/g)의 혼합유산균(Lactobacillus acidophilus, Pediococcus pentosaseus, Bifidobacterium longum SPM1205)을 투여하였으며 대조물질로는 홍삼 추출물(Red ginseng extract) 200 mg (홍삼추출물)/kg (마우스)을 투여하였다. 마지막 실험일에는 locomotor와 elevated plus-maze 실험을 통하여 마우스의 행동변화를 측정하였다. 그 결과, 혼합유산균을 투여한 그룹에서는 스트레스를 일부 억제하는 효과를 보였다. 특히 Elevated plus-maze 실험에서, 스트레스를 받은 마우스는 open zone에서보다 closed zone에서 더욱 많은 시간을 보냈다. 그렇지만 혼합유산균을 투여한 그룹에서는 open zone에서 더욱 오래 시간을 보냈으며 그 시간은 saline과 RGE200 그룹에 비해서도 길었다. 그것은 또한 아무것도 처리하지 않은 Normal 그룹과도 비슷한 결과이다. 그리고 마우스의 분변에서 유산균수를 측정하였는데 스트레스를 가하고 혼합유산균은 투여하지 않은 saline 그룹에서는 유산균수가 감소했지만 혼합유산균을 투여한 LAB100, LAB200 그룹에서는 유산균수가 증가하였다.

• Journal of Dairy Science and Biotechnology
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• 제37권1호
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• pp.40-48
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• 2019

Bifidobacteria are a prototype probiotic, which normally inhabit the intestinal tract of humans. In the present study, four species of Bifidobacterium isolated from the feces of infants were characterized. The tolerance for acid or bile salt, autoaggregation, and antibiotic resistance of the bacteria were examined. The four species were resistant to low pH, bile salts, and up to 3% bile acid. Autoaggregation rates were as high as 90%. The bacteria were consistently resistant to gentamicin, kanamycin, streptomycin, ciprofloxacin, and nalidixic acid. Due to their tolerance to environmental factors like acid and bile salts, B. longum MG723, B. breve MG729, B. bifidum MG731, and B. animalis subsp. lactis MG741 are potentially valuable as probiotics and may be useful for industrial application.

• 한국식품조리과학회지
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• 제26권2호
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• pp.214-219
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• 2010

In this study, phytoestrogen for the industrial production of soybean probiotics by lactic acid bacteria (LAB) was studied in a soybean extract. Soybean was fermented with LAB, Lactobacillus plantarum KCTC 3108 and Bifidobacterum longum ATCC 15707. The change in the content of various isoflavones (aglycone and glucoside) and the $\beta$-glucosidase activity in soybean during fermentation were investigated and shown to be dependent on the starter organism. Soybean extract powder fermented with L. plantarum showed the highest $\beta$-glucosidase activity and the greatest increase in the aglycone content. After 48h of fermentation, the contents of daidzin, genistin and glycitin in L. plantarum decreased from a mean initial levels of $83.03{\pm}2.17$, $168.13{\pm}8.17$ and $20.02{\pm}1.07$, respectively, to mean levels of $5.34{\pm}3.24$, $3.79{\pm}0.57$ and $1.87{\pm}1.09\;mg$/100 g. Whereas, after 48h fermentation, the contents of daidzein, genistein and glycitein increased from a mean initial levels of $8.09{\pm}0.78$, $11.20{\pm}0.84$ and $4.71{\pm}0.46$, respectively, to mean levels of $85.76{\pm}0.84$, $175.87{\pm}2.21$ and $22.41{\pm}0.91\;mg$/100 g. Taken together, these results suggested an increase of aglycones and decrease of glucoside in isoflavones occurred during fermentation, which coincided with an increase of $\beta$-glucosidase activity in the fermented soybean extract powder.