• 한국가금학회지
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• 제27권3호
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• pp.227-233
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• 2000

Preset study was carried out to evaluate characteristics of lactic acid producing bacteria(LAB) in hen's cecum as probiotics value. Distribution of LAB in intestinal tracts was investigated using 5∼25 weeks - old hens. So, 12 strains to LAB with different morphology were isolated purely. Acid tolerance of LAB tested at pH 1, 2, 3, and 4, and bile resistant also tested at 0, 0.3% and 0.5% bile salt concentration. Growth pattern of LAB observed to 60h. All strains of cecal LAB couldn't survive at pH 1, and decreased linearly survival colony after incubation at pH 2 although some strains could survive for 2h. Most of LAB maintained constant number at pH 3 and 4. The bacterial action could increase linearly at 0% bile salt concentration in all of tested strains. However, only one strain could multiply at 0.3% bile salt, others were influenced by bile salt. That tendency was similar at 0.5% bile salt. Growth was peaked at 12 to 18 h after innoculation. After peak, the decreasing pattern of colony was different to strains which some strains decreased rapidly or maintained for long time. The LAB of hen's cecum was similar to intolerance acidity, but different to resistant to bile salt and growth pattern by strain. So, we choose three strains which have probiocs value, and identified as Lactobacillus amylovorus LLA7, Lactobacillus crispatus LLA9 and Lactobacillus vaginalis LLA11.

• Journal of Microbiology and Biotechnology
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• 제9권6호
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• pp.794-797
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• 1999

Lactobacillus acidophilus is known to have an inhibitory activity on growth of Helicobacter pylori and this activity has been attributed to lactic acid and antibacterial agents produced by Lactobacillus. Since every Lactobacilli produces lactic acid, an another factor must exist for L. acidophilus to inhibit H. pylori growth. In this work, the inhibitory activity of L. acidophilus on H. pylori adherence was studied. An immunoabsorbent assay using TLC plate was developed and used for screening the inhibitory activity of various Lactobacilli on H. pylori adherence. Glycolipid, the attachment site for H. pylori, was isolated from blood type O red blood cells and spotted on a TLC plate. The H. pylori adherence increased linearly with increasing amounts of glycolipid spotted on the TLC plate. Various L. acidophilus strains, but not L. casei, appeared to inhibit H. pylori adherence to glycolipid, and the adherence decreased linearly as the concentration of the Lactobacillus increased. The results show that the inhibitory activity of L. acidophilus on H. pylori adherence is an another factor for L. acidophilus to inhibit H. pylori growth.

• 한국식품영양과학회지
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• 제25권1호
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• pp.143-149
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• 1996

균주개량 방법의 일환으로 electrofusion 법을 이용하여 protease 화성, lipase 활성, 내열성, 내산성 등이 우수한 L. bulgaricus와 bacteriocin을 생산하는 L. acidophilus 간의 융합조건을 검토하였다. Electrofusion에 의해 생성된 융합주는 식별하기 위해 streptomycin(2mg/ml)과 lincomycin(5$\mu\textrm{g}$/ml)에 내성을 나타내는 L. bulgaricus 변이주이와 kanamucin (600$\mu\textrm{g}$/ml)에 내성을 나타내는 L. acidophilus 88 변이주를 분리하였다. Electrofusion을 500V/cm, 100mses(49phms, 2300 capacotance)에서 수행했을 때 가장 융합이 잘 일어났으며 전기장의 세시와 시간이 증가할수록 융합요율이 현저히 감소하였다. 2가 양이온은 대체적으로 융합효율을 감속시키는 경향을 나타내었으나 1mM MgCl$_2$에서 융합 효율이 약간 증가하였다. PEG 400을 elec-trogusion buffer에 30%되도록 첨가했을 때, 가장 양호한 융합효율을 나타내었으며 그 이상에서는 오히려 융합 효율이 감소하였다. Electrofusion법과 PEG 매개에 의한 융합법의 융합 효율을 비교한 결과, 거의 비슷한 융합 효율을 나타내었으나 electrofusion 법과 PEG매개에 의한 융합법을 혼합하였을 때 가장 양호한 융합 효율을 나타내었다.

• Asian-Australasian Journal of Animal Sciences
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• 제19권2호
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• pp.262-265
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• 2006

The antioxidative properties of lactobacilli originating from humans (Lactobacillus acidophilus KCTC 3111, Lactobacillus jonsonii KCTC 3141, Lactobacillus acidophilus KCTC 3151, and Lactobacillus brevis KCTC 3498) were investigated using in vitro methods, including inhibition of lipid peroxidation, resistance to hydrogen peroxide and hydroxyl radical, hydroxyl radical scavenging activity, and glutathione peroxidase (GPX) activity. L. acidophilus KCTC 3111 showed the highest inhibition of lipid peroxidation in both intact cells (49.7%) and cell lysate (65.2%). This strain exhibited resistance to hydrogen peroxide and hydroxyl radical, which was viable for 7 h in the concentration of 1.0 mM hydrogen peroxide. In addition, this strain showed high hydroxyl radical scavenging activity. In the GPX activity assay, the highest activity was measured in L. brevis 3498. GPX activity of L acidophilus 3111 was lower than that of L. brevis 3498.

• Journal of Dairy Science and Biotechnology
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• 제30권1호
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• pp.31-36
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• 2012

Lactobacillus rhamnosus GG(ATCC 53103) is one of the best researched probiotic strains in the world. Studies in children have shown that Lactobacillus rhamnosus GG effectively prevents early atopic disease in patients with high risk. The active molecules associated with the immunostimulatory sequence and anti-allergy effects of L. rhamnosus GG have not yet been identified. Unmethylated CpG motifs in bacterial DNA have a mitogenic effect in mouse immune cells, CpG-containing ISS oligodeoxynucleotides are potent Th1 adjuvants, effective in both preventing and reversing Th2-biased immune deviation in allergy models. The genomic DNA of L. rhamnosus GG is a potent inducer of murine B cell and dendritic cell immunoactivation. In L. rhamnosus GG genomic DNA, ID35 shows high activity in ISS assays in both mice and humans. The effects of ID35 result from a unique TTTCGTT motif located at its 5'-end, and its effects are comparable with murine prototype CpG 1826. L. rhamnosus GG is known to secrete proteinaceous pili encoded by the spaCBA gene cluster. The presence of pili structures may be essential for its adhesion to human intestinal mucus, explaining the prolonged duration of intestinal residence of this bacterium, compared to that of non-piliated lactobacilli.

• Journal of Microbiology and Biotechnology
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• 제5권5호
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• pp.257-263
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• 1995

As a first step for developing Lactobacillus strains capable of fermenting starch directly, the $\alpha$-amylase gene (amyL) from Bacillus licheniformis (Kim et al., 1988. Kor. J. Appl. Microbiol. Bioeng. 16: 369-373) was introduced into Lactobacillus casei strains and the level of $\alpha$-amylase expression in transformants was examined. 3 kb EcoRI fragments encompassing amyL were subcloned into the suitable lactococcal cloning vectors (pSA3, pMG36e, and p1L2530) and then recombinant plasmids were introduced into E. coli and L. casei strains by electroporation. Only one recombinant plasmid, $pIL2530\alpha$ was able to transform few L. casei strains tested at low efficiencies. The transformation efficiencies with the plasmid into L. casei YIT 9018 and L. casei A Tee 4646 were less than $10^2/\mu$ g pIL2530\alpha$. The level of amylase activities in L. casei was five to ten-fold lower than that in E. coli cells. $p1L2530\alpha$ was stably maintained in Lactobacillus strains in the presence of Em (5 $\mu $g/ml) but without antibiotic selection, it was unstable so more than 95$%$ of cells lost plasmids after a week of daily subculturing.

• KSBB Journal
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• 제31권1호
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• pp.85-89
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• 2016

Lactic acid fermentations were conducted using water hyacinth. It is known that the pretreatment and enzyme hydrolysis process optimize the potential of water hyacinth. Lactic acid produced by using lactic acid bacteria. All cells were grown at $37^{\circ}C$ and initial pH 5.5. Lactic acid production was measured by HPLC. All Lactobacillus strains could produce lactic acid from pretreated water hyacinth. The highest lactic acid was achieved when lactic acid fermentation was carried out by L. delbrueckii for D-form and L. helveticus for L-form lactic acid production. The lactic acid concentration was 10.70 g/L by L. delbrueckii and it converted glucose in the medium to lactic acid, almost perfectly. Lactic acid production became higher when fermentation was carried out at a controlled pH 5.5. Lactic acid yield and productivity were 0.52 g/g and 0.19 g/L/h for L. helveticus, while L. delbrueckii was 0.64 g/g and 0.27 g/L/h. This study showed that water hyacinth medium could be alternative medium which can replace the complex and expensive medium for growing Lactobacillus strains in production of lactic acid.

• 한국식품과학회지
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• 제29권6호
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• pp.1208-1212
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• 1997

수분활성을 조절한 오징어육으로 제조한 저염 오징어젓갈의 우점 미생물을 분리 동정하고 숙성중 변화를 조사하였다. 우점미생물은 젖산균으로 Lactobacillus plantarum, Lactobacillus brevis, Leuconostoc sp., Pediococcus sp., Streptococcus sp.,로 동정되었으며 총균수의 80%를 차지하였다. 숙성중 Leuconostoc, Streptococcus, Pediococcus는 초기에 급격히 증가하였다가 숙성적기 이후에 급속히 감소하였으며 Lactobacillus는 숙성적기 이후에 급격히 증가하였다. 한편, yeast는 숙성중기 이후에 검출되었으며 숙성말기에 급격히 증가하여 주로 부패에 관여하는 것으로 사료되었다.

• 미생물학회지
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• 제53권2호
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• pp.134-136
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• 2017

이유자돈용 생균제 개발을 위해, 본 연구자들은 유산균의 일종인 Lactobacillus salivairus KLW001 균주를 대한민국 양돈가에서 사육 중인 이유자돈으로부터 분리하였다. 이 균주는 K88 antigen-positive Escherichia coli, Salmonella enterica serovar Typhimurium에 대한 항균 활성이 타 균주보다 우수하여, 우리는 이 균주의 유전체를 분석하였다. 유전체 초안 속의 166개 Contig (${\geq}500bp$)들에서, G+C content (%)가 33.0%였고, 2,326,706 bp 크기의 염기서열을 확보할 수 있었다. 유전체 초안으로부터 항생제 저항 유전자 4개, Phage 관련 유전자 36개, Bile 대사 유전자 3개, CRISPR Spacer 27개를 확인하였다.

• 미생물학회지
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• 제54권3호
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• pp.295-298
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• 2018

Lactobacillus plantarum은 그람 양성, 비운동성의 이형발효세균이며, 다양한 환경에서 서식하고 있다. L. plantarum SK151은 장관상피세포 흡착능이 우수한 균주로서, 김치로부터 분리되었다. SK151 균주의 유전체 길이는 3,231,249 염기쌍이며, G + C 함량은 44.6%이었다. SK151 균주의 유전체에는 비타민 B2 (리보플라빈) 생합성에 필요한 유전자군이 완벽하게 존재하고 있었으며, 세포 흡착과 관련된 유전자도 다수 존재하고 있었다.