• Journal of Dairy Science and Biotechnology
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• v.33 no.2
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• pp.93-102
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• 2015

The aim of this study was to investigate the physiological characteristics and immunomodulatory activity of Lactobacillus fermentum 450 isolated from raw milk. L. fermentum 450 showed optimum growth at $40^{\circ}C$ and exhibited immunomodulatory effects on $interleukin-1{\alpha}$, tumor necrosis $factor-{\alpha}$, and nitrous oxide at concentrations of >2,500 pg/mL, >2,000 pg/mL, and $11.55{\pm}2.95{\mu}M$, respectively. Of the 16 antibiotics tested, L. fermentum 450 exhibited the highest sensitivity to rifampicin, followed by penicillin-G, and the highest resistance to kanamycin, followed by neomycin and polymyxin B. The strain showed high acid phosphatase activity and was comparatively tolerant to bile juice and acid. Moreover, the strain displayed high resistance to Salmonella Typhimurium (63.86%). These results demonstrate that L. fermentum 450 has potential for use as a probiotic with immunomodulatory activity.

• Food Science of Animal Resources
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• v.31 no.4
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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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• v.18 no.1
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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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• v.15 no.3
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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.

• Food Science of Animal Resources
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• v.37 no.6
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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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• v.13 no.6
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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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• v.31 no.10
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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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• v.37 no.3
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• pp.206-212
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• 2019

This study was conducted to investigate the effect of cryoprotectants on the storage stability of Lactobacillus fermentum SK152, which was isolated as a probiotic candidate. Solutions of 10% glucose, trehalose, dextrin, and skim milk powder were used as cryoprotectants. The survival rates of L. fermentum SK152 after freeze-drying were 5.6% (dextrin), 2.2% (skim milk powder), 1.7% (glucose), and 1.5% (trehalose), suggesting that dextrin was most effective at minimizing the cell death of L. fermentum SK152 by lyophilization. The survival rates of L. fermentum SK152 stored at 4℃ ranged from 37% (dextrin)-90% (skim milk powder) after 8 weeks, while those at 20℃ ranged from 4% (dextrin)-12% (skim milk powder) after 7 weeks, indicating that skim milk powder was the best at minimizing the cell death of L. fermentum SK152 during storage, irrespective of storage temperature, among the cryoprotectants used.

• Korean Journal of Microbiology
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• v.53 no.2
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• pp.103-117
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• 2017

The aim of this study was to evaluate the effect of green tea extract on probiotic potential, physico-chemical and functional properties of yogurt fermented with Lactobacillus acidophilus D11 or Lactobacillus fermentum D37 strains isolated from Doenjang. Probiotic activities such as the resistance to artificial digestive juices and the ability to adhere to epithelial cells were slightly higher in yogurt supplemented with green tea extract than in plain yogurt, which may be attributed to the increase in the number of lactic acid bacteria (LAB) by green tea extract supplementation. Furthermore, the microbiological and physico-chemical properties such as the number of LAB, organic acid production and viscosity were significantly (P<0.05) increased in yogurt added green tea extract compared to plain yogurt fermented with L. acidophilus D11. However, the green tea extract did not significantly (P>0.05) affect these properties of yogurt fermented with L. fermentum D37 strain. Meanwhile, the antibacterial activities against Escherichia coli O157 ATCC 43889, Salmonella enteritidis ATCC 13076, and Salmonella typhimurium KCTC 2514 and antioxidant activities including total phenol content, radical scavenging ability, and ferric-reducing antioxidant power were significantly higher in plain yogurt fermented with L. fermentum D37 than with L. acidophilus D11. The antibacterial and antioxidant activities of the yogurt were significantly (P<0.05) increased in proportion to the concentration of green tea extract added to plain yogurt. Consequently, green tea yogurt fermented with L. acidophilus D11 or L. fermentum D37 was considered to be a useful functional food that can inhibit the growth of pathogenic bacteria and scavenge the free radicals from the body cells.

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.150-155
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• 1997

The twenty strains of Lactobacillus genus were tested for the optimal sponge fermentation of soda cracker. The six strains such as L. brevis, L. delbrueckii, L. fermentum, L. leichmanii, L. plantarum and L. sanfrancisco were selected because these strains did not smell off-flavor and showed the high value of TTA (total titrable acidity) after the fermentation. The selected strains consisted of the five strains of L. brevis, L. delbrueckii, L. fermentum, L. leichmanii and L. plantarum that mainly inhabited soda clacker and L. sanfrancisco that existed in San Francisco bread. The lactic acid bacteria were inoculated to the medium containing 10% wheat flour and then pH, TTA, acetic acid and lactic acid were measured during the sponge fermentation. The four strains of L. brevis, L. delbrueckii, L. fermentum and L. plantarum were used for the mixed lactic acid bacteria of sponge fermentation because the TTAs of L. brevis, L. fermentum and L. plantarum were higher than those of other lactic acid bacteria and L. delbrueckii rapidly produced organic acids and a large amount of acetic acid. Among the combination of L. brevis, L. fermentum, L. delbrueckii and L. plantarum, the mixed lactic acid bacteria of L. brevis, L. fermentum and L. plantarum showed the highest TTA, the lowest pH and the largest amount of acetic acid. Therefore, the mixed lactic acid bacteria of L. brevis, L. fermentum and L. plantarum were used for optimal sponge fermentation of soda cracker.