• Journal of Dairy Science and Biotechnology
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• 제33권2호
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• pp.93-102
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• 2015

본 연구는 원유로부터 면역증진 젖산균을 분리 및 동정하고, 이 균주의 생리적 특성을 규명하여 상업적으로의 이용가능성을 검토하고자 실시하였다. 이를 위해 Modified MRS 분별배지를 사용하여 노란색 집락을 형성하는 균주를 대상으로 면역활성이 높은 균주를 선발한 결과, D205 균주가 최종 선발되었다. D205 균주는 $IL-1{\alpha}$, $TNF-{\alpha}$, NO 값이 각각 2,500pg 이상/mL, 2,000 pg 이상/mL, $11.55{\pm}2.95{\mu}M$로 나타났으며, 동정결과 Lactobacillus fermentum으로 판명되었고, Lactobacillus fermentum 450으로 명명하였다. Lactobacillus fermentum 450의 최적 생장 온도는 $40^{\circ}C$이었으며, 답즙산과 산성의 pH에서 모두 우수한 생존력을나타내었다. 효소활성은 leucine arylamidase와 acid phosphatase가 비교적 높게 나타났다. 항생제 내성 실험 결과, kanamycin, neomycin, polymyxin B에 내성이 있는 반면 novobiocin에 감수성을 나타냈으며, Salmonella Typhimurium에 대해 63.86%의 억제 효과를 지니고 있으나, Escherichia coli와 Staphylococcus aureus에 대해서는 항균력이 거의 없는 것으로 나타났다.

• 한국축산식품학회지
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• 제31권4호
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• pp.513-520
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• 2011

In order to develop a new starter culture for fermented milk, Lactobacillus fermentum LC272 was isolated from raw milk and its physiological characteristics were investigated. The vitamin $K_2$ concentration of L. fermentum LC272 was $184.94{\mu}g/L$ in Rogosa medium and $63.93{\mu}g/L$ in the reconstituted skim milk. The optimum growth temperature for L. fermentum LC272 was determined to be $40^{\circ}C$ and it took 24 h for the pH to reach 5.2 under this condition. L. fermentum LC272 was more sensitive to rifampicin relative of the other 15 different antibiotics tested, and showed most resistance to streptomycin. L. fermentum LC272 showed higher activities to leucine arylamidase and acid phosphatase. It was comparatively tolerant to bile juice and acid and displayed high resistance against Salmonella Typhimurium and Staphylococcus aureus with rates of 82.9 and 86.3% respectively. These results demonstrated that L. fermentum LC272 could be an excellent starter culture for fermented milk with high levels of vitamin $K_2$ production.

• Asian-Australasian Journal of Animal Sciences
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• 제18권1호
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• pp.90-95
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• 2005

Lactic acid bacteria were isolated from silage, which produce high level of hydrogen peroxide in cell culture supernatant. The 16S rDNA sequences of the isolate matched perfectly with that of Lactobacillus fermentum (99.9%), examined by a 16S rDNA gene sequence analysis and similarity search using the GenBank database, thus named L. fermentum CS12-1. L. fermentum CS12-1 showed resistance to low pH and bile acid. The production of hydrogen peroxide by L. fermentum CS12-1 was confirmed by catalase treatment and high-performance liquid chromatography. L. fermentum CS12-1 accumulated hydrogen peroxide in culture broth as cells grew, and the highest concentration of hydrogen peroxide reached 3.5 mM at the late stationary growth phase. The cell-free supernatant of L. fermentum CS12-1 both before and after neutralization inhibited the growth of enterotoxigenic Escherichia coli K88 that causes diarrhea in piglets.

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.603-608
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• 2005

We recently isolated a novel probiotic strain, Lactobacillus fermentum PL9005 (KCCM-10250), from infant feces and showed that it had a potential immunoenhancing effect. In the present study, a safety assessment of the bacteria was performed using a BALB/c mouse model. Mice were administered with L. fermentum PL9005 daily for 28 days. There were no detectable changes in body weight, feed intake, or clinical signs, and no significant difference in hematological parameters or blood biochemistry between the L. fermentum PL9005-fed and control groups. Bacterial translocation was detected in the mesenteric lymph nodes, liver, and spleen of some mice with and without L. fermentum PL9005 feeding, however, the organisms were not related to ingestion of L. fermentum PL9005; this was confirmed by PCR using a species-specific primer. No gross lesions were detected in the liver, spleen, or intestine of L. fermentum PL9005-fed or control mice. Mucosal thickness in the ileum, cecum, and colon of L. fermentum PL9005-fed mice was not significantly different from that of corresponding organs in control mice. No inflammation or epithelial cell degeneration in the intestines was observed in any mice. These results indicate that ingestion of L. fermentum PL9005 is safe in mice and can be applied in the functional food market.

• 한국축산식품학회지
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• 제37권6호
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• pp.931-939
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• 2017

Alcoholic liver disease (ALD) is a complex multifaceted disease that involves oxidative stress and inflammation as the key mediators. Despite decades of intensive research, there are no FDA-approved therapies, and/or no effective cure is yet available. Probiotics have received increasing attention in the past few years due to their well-documented gastrointestinal health-promoting effects. Interestingly, emerging studies have suggested that certain probiotics may offer benefits beyond the gut. Lactobacillus fermentum LA12 has been previously demonstrated to play a role in inflammatory-related disease. However, the possible protective effect of L. fermentum LA12 on ALD still remain to be explored. Thus, the aim of this study was to evaluate the possible protective effect of L. fermentum LA12 on alcohol-induced gut barrier dysfunction and liver damage in a rat model of alcoholic steatohepatitis (ASH). Daily oral administration of L. fermentum LA12 in rat model of ASH for four weeks was shown to significantly reduced intestinal nitric oxide production and hyperpermeability. Moreover, small intestinal histological- and qRT-PCR analysis further revealed that L. fermentum LA12 treatment was capable of up-regulating the mRNA expression levels of tight junction proteins, thereby stimulating the restitution of barrier structure and function. Serum and hepatic analyses also revealed that the restoration of epithelial barrier function may prevent the leakage of endotoxin into the blood, subsequently improve liver function and hepatic steatosis in the L. fermentum LA12-treated rats. Altogether, results in this study suggest that L. fermentum LA12 may be used as a dietary adjunct for the prevention and treatment of ASH.

• Journal of Microbiology and Biotechnology
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• 제13권6호
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• pp.919-925
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• 2003

Alcohol consumption has numerous health consequences for the human body. For example, heavy drinking on a daily basis causes liver diseases, and certain products such as acetaldehyde produced from alcohol metabolism are more toxic than alcohol itself. Accordingly, the current study evaluated the role of Lactobacillus fermentum MG590 to enhance the removal of the toxic effect of alcohol in alcohol metabolism. The maximum activities of the alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) by L. fermentum MG590 were observed after 6 h of culture. The production of ADH and ALDH by L. fermentum MG590 was also confirmed by SDS-PAGE. Six hours after the addition of alcohol to a culture broth of L. fermentum MG590, the alcohol concentration decreased from 7.5 to 2.7％. From an in vitro evaluation based on hepatocytes, the viability of hepatocytes in a medium containing alcohol and the cytosol of L. fermentum MG590 was higher than that in a medium containing only alcohol. From an in vivo test using SD rats fed a 22％ alcoholic drink, the blood alcohol concentration (BAC), glutamic-oxaloacetic transaminase (GOT), and glutamic-pyruvic transaminase (GPT) in the rats fed a medium containing L. fermentum MG590 were lower than those in the rats fed a medium containing only the alcohol drink. These results demonstrate that the ADH and ALDH produced by L. fermentum MG590 play an important role in detoxicating alcohol in vivo. Therefore, a fermentation broth of L. fermentum MG590 could be used as an effective alcohol detoxification drink.

• Journal of Microbiology and Biotechnology
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• 제31권10호
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• pp.1383-1392
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• 2021

Carbapenem-resistant Enterobacteriaceae (CRE) that produce Klebsiella pneumoniae carbapenemase are increasingly reported worldwide and have become more and more resistant to nearly all antibiotics during the past decade. The emergence of K. pneumoniae strains with decreased susceptibility to carbapenems, which are used as a last resort treatment option, is a significant threat to hospitalized patients worldwide as K. pneumoniae infection is responsible for a high mortality rate in the elderly and immunodeficient individuals. This study used Lactobacillus fermentum as a candidate probiotic for treating CRE-related infections and investigated its effectiveness. We treated mice with L. fermentum originating from the vaginal fluid of a healthy Korean woman and evaluated the Lactobacilli's efficacy in preventive, treatment, nonestablishment, and colonization mouse model experiments. Compared to the control, pre-treatment with L. fermentum significantly reduced body weight loss in the mouse models, and all mice survived until the end of the study. The oral administration of L. fermentum after carbapenem-resistant Klebsiella (CRK) infection decreased mortality and illness severity during a 2-week observation period and showed that it affects other strains of CRK bacteria. Also, the number of Klebsiella bacteria was decreased to below 5.5 log₁₀ CFU/ml following oral administration of L. fermentum in the colonization model. These findings demonstrate L. fermentum's antibacterial activity and its potential to treat CRE infection in the future.

• Journal of Dairy Science and Biotechnology
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• 제37권3호
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• pp.206-212
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• 2019

L. fermentum SK152의 동결건조에 의한 생균수 감소에 동결보호제가 미치는 영향을 조사하기 위해, 균체를 dextrin, skim milk powder, glucose, trehalose 10% 용액에 각각 현탁한 후에 동결건조하였다. 동결건조 후의 생존율은 각각 5.6%(dextrin), 2.2%(skim milk powder), 1.7%(glucose), 1.5%(trehalose)로서, dextrin을 첨가한 경우에 생존률이 가장 높게 나타났다. 동결건조한 L. fermentum SK152를 냉장(4℃) 및 상온(20℃)에 7-8주간 저장하면서 동결보호제의 종류에 따른 생존률을 조사한 결과, 4℃ 보관 시에는 동결보호제의 종류에 상관없이 저장기간이 길어져도 생존률이 서서히 감소하는 경향을 나타내었다. 저장 8주 후의 생존률은 37%(dextrin)-90%(skim milk powder)에 이르렀으며, skim milk powder 첨가시에 가장 높은 생존률을 나타내었다. 한편, 20℃ 보관 시에는 동결보호제의 종류에 상관없이 저장기간에 길어질수록 4℃에 비하여 생존률이 급격히 감소하는 경향을 나타내었다. 저장 7주 후의 생존률은 4%(dextrin)-12%(skim milk powder)에 이르렀으며, 이중 가장 높은 생존률을 나타낸 동결보호제는 skim milk powder이었다.

• 미생물학회지
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• 제53권2호
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• pp.103-117
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• 2017

본 연구에서는 된장으로부터 분리된 Lactobacillus acidophilus D11 또는 Lactobacillus fermentum D37 균주로 발효시킨 요구르트의 프로바이오틱로서의 가능성, 물리 화학적 및 기능적 특성에 대한 녹차 추출물의 영향을 조사하였다. 인공 소화액에 대한 저항성과 상피 세포에 대한 부착력과 같은 프로바이오틱활성은 플레인 요구르트보다 녹차 추출물을 첨가한 요구르트에서 다소 높게 나타났는데, 이는 유산균의 수의 증가에 기인하는 것으로 추정되었다. L. acidophilus D11로 발효시킨 플레인 요구르트에 녹차 추출물을 첨가한 경우 유산균수, 유기산 함량 및 점도와 같은 요구르트의 물리 화학적 특성도 유의하게 (P<0.05) 증가하였다. 하지만 녹차 추출물은 L. fermentum D37 균주 발효시킨 요구르트의 물리 화학적 특성에는 유의한 영향을 미치지 않았다 (P>0.05). 한편, Escherichia coli O157 ATCC 43889, Salmonella enteritidis ATCC 13076 및 Salmonella typhimurium KCTC 2514에 대한 항균 활성 및 총 페놀 함량, 라디칼 소거능 및 철 환원력과 같은 항산화 활성은 L. acidophilus D11 보다는 L. fermentum D37로 발효시킨 플레인 요구르트에서 현저히 높았다. 게다가 요구르트의 항균 및 항산화 활성은 녹차 추출물의 농도에 비례하여 유의적으로 증가하였다(P<0.05). 결론적으로, L. acidophilus D11 또는 L. fermentum D37로 발효시킨 녹차 요구르트는 병원성 세균의 성장을 억제하고 체세포 내에 생성된 자유 라디칼을 제거 할 수 있는 유용한 기능성 식품으로 이용할 수 있는 것으로 판단되었다.

• 한국식품과학회지
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• 제29권1호
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• pp.150-155
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• 1997

소다 크레커에서 분리된 미생물은 대부분 젖산균인 Lactobacillus의 속이므로 약 20종의 기존에 분리된 Lactobacillus속의 미생물들을 스폰지 발효에 사용하였고, 이중에서 발효후 이취가 없고 총적정산도가 높은 6종의 젖산균을 선별하였다. 선별된 젖산균은 소다 크레커의 스폰지발효에 관여하는 주요 젖산균으로 보고된 L. brevis, L. delbrueckii, L. fermentum, L. leichmanii와 L. plantarum 등 5종과 San Francisco sour bread의 주요 젖산균인 L. sanfrancisco이었다. 선별된 6종의 젖산균을 10%의 밀가루 용액에 접종하여 스폰지 발효 동안의 pH, 총적정산도 및 유기산(lactic acid와 acetic acid)의 변화를 측정한 결과 L. brevis, L. fermentum과 L. plantarum의 pH는 많이 저하하였고 총적정산도는 많이 증가하였으며 L. delbrueckii의 경우는 유기산이 빨리 생성되었고 주 유기산인 acetic acid를 비교적 많이 생성하여 혼합균주의 조합으로 사용하였다. 4가지 균주의 여러 가지 조합중 L. brevis, L. fermentum과 L. plantarum의 혼합젖산균을 사용한 결과 총적정산도의 상승과 pH의 저하와 acetic acid의 생성력이 가장 뛰어나 이 혼합젖산균을 최적 스폰지 발효를 위한 가장 좋은 혼합젖산균으로 선택하였다.