• KSBB Journal
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• v.18 no.4
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• pp.294-300
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• 2003

In the previous study, we have isolated several vaginal lactobacilli from Korean woman and selected one of them (KLB12) for further study, which was indentified as Lactobacillus fermentum by sequence analysis of 16S rRNA gene. Formulated L. fermentum KLB12 can be used for ecological treatment of bacterial vaginosis. For pharmaceutical formulation, the spray-drying process is required where stress such as high temperature is routinely applied. In this study, we found that heat stress at 60$^{\circ}C$ for 20∼30min reduced the viable cell population of KLB12 by 10$\sub$6/～10$\sub$9/. However, adaptation of KLB12 cells at 52$^{\circ}C$ made them more thermotolerant upon exposure to 60$^{\circ}C$. The level of thermal protection in RSM (reconstituted skim milk) by adaptation in acid (pH 5), cold (4$^{\circ}C$), ethanol (3％), NaCI (0.3M) was also examined. Although not as efficient as the homologous stress, adaptations in both cold and NaCI gave considerable cross protection against heat stress. When chloramphenicol was added during heat adaptation, adaptation effect was abolished. This suggests that de novo protein synthesis is necessary during the adaptation process. Important changes in proteome during heat adaptation was examined with two-dimensional gel electrophoresis.

• Food Science of Animal Resources
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• v.41 no.2
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• pp.343-352
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• 2021

The objective of this study was to evaluate the effects of Lactobacillus acidophilus ATCC 43121 and L. fermentum MF27 on biochemical indices in the serum, cholesterol metabolism in the liver and mucin expression in the gallbladder in lithogenic diet (LD)-induced C57BL/6J mice to determine the preventive effects of lactobacilli on gallstone formation. By the end of 4 wk of the experimental period, mice fed on a LD with high-fat and high-cholesterol exhibited higher levels of total and low-density lipoprotein cholesterol in the serum compared to mice fed on control diet or LD with L. acidophilus ATCC 43121 (LD+P1; p<0.05). Cholesterol-lowering effects observed in the LD+P1 and LD with L. fermentum MF27 (LD+P2) groups were associated with reduced expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase in the liver compared to the LD group (p<0.05). Furthermore, expression of the gel-forming mucin, including MUC5AB and MUC5B, was suppressed in the LD+P1 and LD+P2 groups compared to the LD group (p<0.05). Therefore, steady intake of both L. acidophilus ATCC 43121 and L. fermentum MF27 may have the ability to prevent the formation of cholesterol gallstones in LD-induced C57BL/6J mice.

• 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.

• Microbiology and Biotechnology Letters
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• v.22 no.3
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• pp.266-270
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• 1994

A bacteriocin was isolated from the supernatant fluid of M17G broth culture of Lactococcus sp. HY 449 strain, which showed strong inhibitory activity against the growth of selective indicator strain, Lactobacillus fermentum IFO3023. When the bacteriocin wasa added to the growing indicator cells or cell suspensions, viable cells and optical density were density were decreased, indicating bacteriolytic mode of action. Electron microscopic observation of indicator cells treated with bacteriocin revealed apparent damages on the cell surface and eventual lysis of cell walls.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.446-452
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• 2011

Total 480 lactic acid-producing bacteria were isolated from five kinds of kimchi, and their antibacterial activity was tested against Salmonella enterica serovar Typhimurium, Bacillus subtilis, and Pseudomonas aeruginosa using an agar diffusion assay. Among them, 340 isolates showed a halo on MRS agar against one or more indicator strains, which were identified using multiplex PCR, an API 50CHL kit, and a 16S rDNA sequence analysis. As a result, 169 Lactobacillus plantarum, 20 Lactobacillus fermentum, two Lactobacillus paracasei ssp. paracasei, two Lactobacillus sp., and 15 Pediococcus sp. were identified. This may be the first report on the isolation of antibacterial Lactobacillus fermentum from kimchi.

• KSBB Journal
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• v.20 no.2 s.91
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• pp.76-83
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• 2005

Lactic acid bacteria were isolated from pig feces for probiotics. The six isolated strains were identified as Lactobacillus paracasei (Lp), Lactobacillus fermentum (Lf), Lactobacillus brevis (Lb), Lactobacillus plantarum (P1 , P2), and Pediococcus pentosaceus (P3) by its sugar utilization, morphological and physiological characteristics. Pl was showed largest antibacterial inhibition zone among the isolated strains. It was against Salmonella gallinarum 25mm, E. coli 20.5mm, Staphylococcus aures 24mm, and Pseudomonas aeruginosa 28mm by inhibitory zone, respectively. Lf was showed hyper acid tolerance, $80\%$ survival rate for 40 minutes, and P1, Lb showed hyper bile tolerance, $408\%,\;283\%$ survival rate for 9 hrs, respectively. Therefore the Lf, P1, and P2 strains were expected to probiotics.

• 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.

• Preventive Nutrition and Food Science
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• v.3 no.4
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• pp.329-333
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• 1998

Cell wall (lactic acid bacteria-sonicated precipitate ; LAB-SP) and cytosoll(lactic acid bacteria-sonicated supernatant ; LAB-SS) fractions were prepared from kimchi fermenting lactic acid bacteria such as Leuconostoc mesenteroides, Lactobacillus brevis, Lactobacillus fermentum , Lactobacillus plantarum and Pediococcus acidilactici, with Lactobacillus acidophillus isolated from yogurt. Using the Ames mutagenicity test and SOS chormotest system, the antimutagenic acitivity of those cell fractions was studied . One hundered eighty $\mu$l of LAB-SP from lactic acid bacteria isolated from kimchi, excepting Pediococcus acidilactici, supressed the mutagenicity of 4-nitroquinoline-1-oxide(4-NQO) in Ames mutagenicity test and SOS chromotes system , by above 90% and 60% , respectively. LAB-SP from lactic acid bacteria also inhibited the mutagenicity mediated by 3-amino-1-methyl-5H-pyrido [4,3-b]indole (Trp-P-2). Lactobacillus fermentum, Lactobacillus plantarum, and Lactobacillus acidphillus had higher antimutagenicity against Trp-P-2). Lactobacillus fermentum , Lactobacillus plantarum , and Lactobacillus acidphillus had higher antimutagenicity against Trp-P-2 than the other lactic acid bacteria. However, LAB-SS of lactic acid bacteria did not show any mutagenic activity against 4-NQO in Ames mutagenicity test and SOS chromotest systems. On the mutagenicity of MEIQ and Trp-P-2 , LAB-SS of lactic acid bacteria from kimchi or dairy products exhibited a weaker inhibitory effect than LAB-SP of those bacteria. These results represent that, whether the lactic acid bacteria from kimchi are viable or nonviable, antimutagenic acitivity was still effective. We suggest that the strong, antimutaganic activity of lactic acid bacteria might be found in the cell wall fraction , rather than in the cytosol fraction.

• Microbiology and Biotechnology Letters
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• v.28 no.5
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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.

• 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.