• 한국식품과학회지
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• 제35권6호
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• pp.1244-1247
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• 2003

발효 및 유산균 제품에 모유만을 먹은 생후 3개월된 유아의 분변으로부터 bromocresol pule을 함유한 MRS 배지에서 노란색의 집락을 형성하는 균주들을 내산성 및 담즙산 내성이 우수한 13종의 Lactobacillus 균주들을 분리하였으며 당발효성 및 생화학적 실험을 토대로 분리된 유산균들을 동정하였다. 최종적으로 선발한 균주를 L. acidophilus로 KY1909로 명명하였다. Lactic acid 생성 능력을 평가한 후 이성질체를 분석한 결과 상업적으로 이용되는 L. acidophilus NCFM, L. acidophilus CH5, L. acidophilus NOCKS 균주들은 전체 lactic acid 중에서 L(+) form이 차지하는 비율이 각각 52.49, 40.63 및 63.13%로 나타났으나, L. acidophilus KY1909는 L(+) lactic acid의 비율이 93.96%로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제26권11호
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• pp.1829-1835
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• 2016

Dental caries is caused by cariogenic biofilm, an oral biofilm including Streptococcus mutans. Recently, the prevention of dental caries using various probiotics has been attempted. Lactococcus lactis HY 449 is a probiotic bacterium. The aim of this study was to investigate the effect of L. lactis HY 449 on cariogenic biofilm and to analyze its inhibitory mechanisms. Cariogenic biofilm was formed in the presence or absence of L. lactis HY 449 and L. lactis ATCC 19435, and analyzed with a confocal laser microscope. The formation of cariogenic biofilm was reduced in cultures spiked with both L. lactis strains, and L. lactis HY 449 exhibited more inhibitory effects than L. lactis ATCC 19435. In order to analyze and to compare the inhibitory mechanisms, the antibacterial activity of the spent culture medium from both L. lactis strains against S. mutans was investigated, and the expression of glucosyltransferases (gtfs) of S. mutans was then analyzed by real-time RT-PCR. In addition, the sucrose fermentation ability of both L. lactis strains was examined. Both L. lactis strains showed antibacterial activity and inhibited the expression of gtfs, a nd t he d ifference b etween both strains did not show. In the case of sucrose-fermenting ability, L. lactis HY 449 fermented sucrose but L. lactis ATCC 19435 did not. L. lactis HY 449 inhibited the uptake of sucrose and the gtfs expression of S. mutans, whereby the development of cariogenic biofilm may be inhibited. In conclusion, L. lactis HY 449 may be a useful probiotic for the prevention of dental caries.

• 한국미생물·생명공학회지
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• 제28권5호
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• pp.279-284
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• 2000

This study was per-formed to screen lactic acid bacteria poultry for the probiotic use. Among the previously obtained acid tolerant, 139 strains, 111 strains were selected with MRS medium containing 0.3% oxgall. 34 strains of 111 was re-selected by Gram-staining and acid producing ability. These strains was identified by MIDI Sherlock Microbial Identification System. Among the identified 34 strains Lactobacillus fermenum YL-3 was selected for the final pro-biotic use because of the good growth and high survival rate at pH 2.0. 60%, 50% and 40% cells of Lactobacillus fermentum YL-3 survived at pH 3.0, 2.5 and 2.0, respectively. More than $10^{7}$ / CFU/ml survived when exposed with the number of $10^{8}$ CFU/ml at pH 2.0 after 12 hr. L.fermenum YL-3 maintained growth in MRS broth containing 0.3, 0.5, 1.0 and 2.0% oxgall for 24 hr. L.fermenum YL-3 showed an inhibitory effect against pathogenic strains of Sal. enteritidis and E. coli O157:H7. In mixed culture with L.fermenum YL-3 Sal. enteritidis lost ability com-pletely in 15 hrs and E. coil O157:H7 in 16 hrs.

• 산업식품공학
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• 제13권4호
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• pp.352-359
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• 2009

마늘의 항균력에 저항성을 갖는 유산균을 분리하기 위해서 마늘 추출물이 첨가된 배지에서 생육하는 112 균주를 김치, 젓갈, 장아찌류로부터 분리하였다. 이 중에서 14균주에 대해서 내산성 및 내담즙성 그리고, 가축 병원성 세균인 Salmonella choleraesuis, Escherichia coli, Staphylococcus aureus, Shigella flesneri에 대해 항균력을 조사한 결과, 파김치 유래의 P'GW50-2 균주가 가장 우수한 특성을 지니고 있어 생균제로 이용 가능한 균주로 선발하였다. 선발된 균주는 16S rRNA 유전자의 염기서열 분석결과 Lactobacillus plantarum으로 동정되었고 L. plantarum TJ-LP-002으로 명명하였다. L. plantarum TJ-LP-002는 Bacillus cereus, S. aureus, Clostridium perfringens와 같은 Gram 양성균과 Aeromonas hydrophila, E. coli, Pseudomonas, Salmonella, Shigella와 같은 Gram 음성균에 대해서 비교적 넓은 항균활성을 나타내었다.

• 미생물학회지
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• 제54권4호
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• pp.436-441
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• 2018

인삼은 우수한 약리 활성 작용을 보이는 전통적인 약초이다. 본 연구에는 프로바이오틱스 Lactobacillus helveticus KII13과 Pediococcus pentosaceus KID7 균주를 진세노사이드(ginsenoside) 함량을 증가시키기 위해 조 인삼 추출물을 발효시켜 진세노사이드를 형질전환 시키는데 사용되었다. 발효삼 추출물의 TLC(Thin-layer chromatography) 분석 결과, 5일간의 발효 후 주요 사포닌인 진세노사이드 Rg3, Rh1 및 Rh2로 변환되는 것으로 나타났다. HPLC 분석을 수행하여 주요 및 미량 진 세노사이드를 정량화하였다. 3일째에는 Rg3가 나타나고, 5일째에는 Rh2 및 Rh1이 나타난다. L. helveticus KII13과 P. pentosaceus KID7의 공동 배양은 주요 진세노사이드(Rb1과 Rg1)를 미량 진세노사이드(Rg3, Rh2, Rh1)로 전환시키는 것을 학인하였다.

• Journal of Microbiology and Biotechnology
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• 제31권7호
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• pp.999-1010
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• 2021

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the environment. They are highly toxigenic and carcinogenic. Probiotic bacteria isolated from fermented foods were tested to check their ability to degrade and/or detoxify PAHs. Five probiotic bacteria with distinct morphologies were isolated from a mixture of 26 fermented foods co-cultured with benzo(a)pyrene (BaP) containing Bushnell Haas minimal broth. Among them, B. velezensis (PMC10) significantly reduced the abundance of BaP in the broth. PMC10 completely degraded BaP presented at a lower concentration in broth culture. B. velezensis also showed a clear zone of degradation on a BaP-coated Bushnell Haas agar plate. Gene expression profiling showed significant increases of PAH ring-hydroxylating dioxygenases and 4-hydroxybenzoate 3-monooxygenase genes in B. velezensis in response to BaP treatment. In addtion, both live and heat-killed B. velezensis removed BaP and naphthalene (Nap) from phosphate buffer solution. Live B. velezensis did not show any cytotoxicity to macrophage or human dermal fibroblast cells. Live-cell and cell-free supernatant of B. velezensis showed potential anti-inflammatory effects. Cell-free supernatant and extract of B. velezensis also showed free radical scavenging effects. These results highlight the prospective ability of B. velezensis to biodegrade and remove toxic PAHs from the human body and suggest that the biodegradation of BaP might be regulated by ring-hydroxylating dioxygenase-initiated metabolic pathway.

• Journal of Microbiology and Biotechnology
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• 제34권2호
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• pp.314-329
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• 2024

Fifteen cyclic dipeptides (CDPs) containing proline, one cyclo(Phe-Ala) without proline, and a non-peptidyl ᴅⳑ-3-phenyllactic acid were previously identified in the culture filtrates of Lactobacillus plantarum LBP-K10, an isolate from kimchi. In this study, we used Japanese quail (Coturnix japonica) eggs to examine the effects of probiotic supplementation on the antimicrobial CDPs extracted from quail eggs (QE). Eggshell-free QE were obtained from two distinct groups of quails. The first group (K10N) comprised eggs from unsupplemented quails. The second group (K10S) comprised eggs from quails supplemented with Lb. plantarum LBP-K10. The QE samples were extracted using methylene chloride through a liquid-liquid extraction process. The resulting extract was fractionated into 16 parts using semi-preparative high-performance liquid chromatography. Two fractions, Q6 and Q9, were isolated from K10S and identified as cis-cyclo(ⳑ-Ser-ⳑ-Pro) and cis-cyclo(ⳑ-Leu-ⳑ-Pro). The Q9 fraction, containing cis-cyclo(ⳑ-Leu-ⳑ-Pro), has shown significant inhibitory properties against the proliferation of highly pathogenic multidrug-resistant bacteria, as well as human-specific and phytopathogenic fungi. Some of the ten combinations between the remaining fourteen unidentified fractions and two fractions, Q6 and Q9, containing cis-cyclo(ⳑ-Ser-ⳑ-Pro) and cis-cyclo(ⳑ-Leu-ⳑ-Pro) respectively, demonstrated a significant increase in activity against multidrug-resistant bacteria only when combined with Q9. The activity was 7.17 times higher compared to a single cis-cyclo(ⳑ-Leu-ⳑ-Pro). This study presents new findings on the efficacy of proline-containing CDPs in avian eggs. These CDPs provide antimicrobial properties when specific probiotics are supplemented.

• 대한수의학회지
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• 제49권4호
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• pp.335-343
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• 2009

The pathogenicity and acute toxicity of Lactobacillus (L.) pentosus PL11 from eel (Anguilla japonica) were investigated using male and female Sprague-Dawley rats. The pathogenicity of L. pentosus PL11 was examined after treating the rats with $10^{11}$ CFU/mL, $10^9$ CFU/mL or $10^7$ CFU/mL doses of L. pentosus PL11 culture or 0.85% NaCl (Control) intragastrically. For acute toxicity studies, rats were treated with dried culture broth of L. pentosus PL11 at doses of 5,000 mg/mL, 2,500 mg/mL, 1,250 mg/mL or 625 mg/mL or Lactobacilli MRS broth (Control), and clinical signs or mortalities were monitored for two weeks. The results of the present investigation revealed no mortalities or obvious clinical signs in rats administered with the live bacterial cultures or dried culture broth at any investigated dose level. Also, no significant differences were observed in net body weight gain, gross pathological findings, feed and water consumption and body temperature among the different treatment groups and between the treated and control rats. It can be concluded from the above findings that L. pentosus PL11 is a safe probiotic strain with potential as feed additive to increase the feed efficiency or health of fish.

• KSBB Journal
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• 제18권5호
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• pp.371-376
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• 2003

프로바이오틱 생균인 B. polyfermenticus SCD의 유용성을 확인하기 위해 항산화 및 콜레스테롤 저하 효과를 검증하였다. DPPH법에 의한 항산화 활성은 48% 정도였으며, TCA법에 의한 활성은 45%로 측정되었다. 그리고 TBARS 법에 의해 측정된 활성은 stimulator가 존재할 때 60%에 달하였으며, SOD 유사활성은 15% 정도였다. 이러한 활성은 기존의 항산화제인 BHT나 $\alpha$-tocopherol의 1% 용액과 비교할 때, 비슷하거나 약간 낮은 수치를 보여 준다. 향후 항산화 물질이 정제되어 이 물질의 1% 용액과 1% 농도의 기존 항산화제의 활성을 비교하여야 한다. 그러나 이 같은 뚜렷한 B. polyfermenticus SCD의 항산화력을 바탕으로 천연 항산화제 개발이 가능하다고 판단된다. 한편 B. polyfermenticus SCD의 콜레스테롤 저하 효과는 0.3% oxgall이 존재할 때, 64% 정도였다. 이 수치는 oxgall이 존재하지 않을 때 수치(67%)와 비교할 때, 큰 변화가 없었다. 그리고 콜레스테롤 저하 기작은 세포내 흡착에 의한 것으로 판단되었다.

• 한국식품영양학회지
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• 제24권1호
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• pp.117-123
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• 2011

This study was conducted to establish process conditions for plant-originated lactic acid production using a mixed culture of plant originated lactic acid bacteria, Lactobacillus sakei B2-16, and Lactobacillus plantarum P23, which were isolated from kimchi, and Bacillus subtilis, which was TP6 isolated from Denjang. Soybean medium was pretreated for 10 minutes at $110^{\circ}C$ and hydrolyzed with 0.2%(w/v) cellulase at $55\sim60^{\circ}C$ for at least 2 hrs. The quality of the final fermentation product was influenced by the inoculation ratio of the Lactobacillus sakei B2-16, Lactobacillus plantarum P23, and Bacillus subtilis TP6. The optimum microorganism inoculation ratio was 1:0.7:0.3, Lactobacillus sakei B2-16: Lactobacillus plantarum P23: Bacillus subtilis TP6, respectively. The sensory characteristics of the product were a refreshing sourness and a soft flavor.