• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.644-648
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• 1994

Lactic acid bacteria(LAB) and its metabolites were tested for their inhibitory effect on the growth of Staphylococcus aureus in vitro. When S. aureus and LAB were incubated simultaneously in MRS broth, the growth of S. aureus began to be suppressed after 12 hour of incubation, completely inactivated within 24 hour of incubation by L. lactis and 48 hour by L. casei, L. acidophilus, and Sc. thermophilus. The pH values of media incubated by S. aureus and LAB were about 4.5 at 12 hour of incubation and 3.5 at 48 hour. The metabolites of the four LAB all exerted antibacterial activity on the growth of S. aureus in TS broth, but is got lost the antibacterial activity by heating ($100^{\circ}C,\;20\;min$). On treating metabolites with catalase, only L. lactis were lost its antibacterial activity. Organic acids (acetate, lactate) showed more active inhibition than inorganic acid (HCl) at pH 3.5, 4.5 but there is no significant differance at pH 5.5, 6.5.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.402-407
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• 2008

The synergistic antimicrobial effect of Achyranthes japonica Nakai (AJN) and Bifidobacterium extracellular factors against Clostridium difficile were measured using a turbidity method. Each broth supernatant of Bifidobacterium infantis ($68.8{\pm}0.02%$) and Bifidobacterium adolescentis ($33.2{\pm}0.2%$) obtained by adding ethyl acetate soluble fractionate from A. japonica Nakai ethanolic extracts (AJNEA, 100 ppm, no inhibition) showed high synergistic antimicrobial activity against C. difficile. In addition, the antimicrobial activity in a laboratory medium and yogurt products against C. difficile were evaluated. In yogurt prepared with a starter 5 (Lactobacillus acidophilus: Streptococcus thermophilus: B. adolescentis =1 : 1 : 1) and a starter 4 (L. acidophilus: S. thermophilus: B. infantis=1 : 1 : 1) and 0.5% AJNEA powder, high antimicrobial effects were recorded that measured 79.0 and 65.2%, respectively. The results indicated the potential of AJN extract for use as an antimicrobial agent. In addition, the efficiency of the antimicrobial activity of the extracts was further improved in combination with lactic acid bacteria, which suggests that they have the potential to be used as a highly effective antibiotic-tolerant microorganism prevention system. Such a strategy can be used for alternative drugs or functional food additives for treatment of antibiotic-associated diarrhea.

• Archives of Pharmacal Research
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• v.28 no.3
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• pp.325-329
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• 2005

The hepatoprotective activity of lactic acid bacteria (Lactobacillus brevis HY7401, Lactobacillus acidophilus CSG and Bifidobacterium longum HY8001), which inhibited $\beta$-glucuronidase productivity of intestinal microflora, on t-BHP- or CCl$_4$-induced hepatotoxicity of mice were evaluated. These oral administration of lactic acid bacteria lowered $\beta$-glucuronidase production of intestinal microflora as well as Escherichia coli HGU-3. When lactic acid bacteria at a dose of 0.5 or 2 g (wet weight)/kg was orally administered on CCl$_4$-induced liver injury in mice, these bacteria significantly inhibited the increase of plasma alanine transferase and aspartate transferase activities by $17-57\%$ and $57-66\%$ of the $CCI_4$ control group, respectively. These lactic acid bacteria also showed the potent hepatoprotective effect against t-BHP-induced liver injury in mice. The inhibitory effects of these lactic acid bacteria were more potent than that of dimethyl diphenyl bicarboxylate (DDB), which have been used as a commercial hepatoprotective agent. Among these lactic acid bacteria, L. acidophilus CSG exhibited the most potent hepatoprotective effect. Based on these findings, we insist that an inhibitor of $\beta$-glucuronidase production in intestine, such as lactic acid bacteria, may be hepatoprotective.

• Journal of Marine Bioscience and Biotechnology
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• v.10 no.2
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• pp.44-52
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• 2018

A synthetic pathway, which consisted of fatty acid double bond hydratase, alcohol dehydrogenase, and Baeyer-Villiger monooxygenase, was applied to Chlorella oil to produce ester fatty acids, which can be hydrolyzed into medium chain fatty acids. Since linoleic acid is a major fatty acid constituent of Chlorella oil, a fatty acid double bond hydratase from Lactobacillus acidophilus NBRC13951, which is able to convert linoleic acid into 13-hydroxyoctadec-9-enoic acid, was used. Recombinant Escherichia coli expressing the fatty acid double bond hydratase from L. acidophilus NBRC13951 successfully transformed linoleic acid in Chlorella oil hydrolysates into 13-hydroxyoctadec-9-enoic acid with approximately 60% conversion yield. 13-Hydroxyoctadec-9-enoic acid was further converted into ester fatty acids by the recombinant E. coli expressing a long chain secondary alcohol dehydrogenase and a Baeyer-Villiger monooxygenase. The resulting ester fatty acids were then hydrolyzed into medium chain fatty acids by a lipase. Overall, industrially relevant medium chain fatty acids were produced from Chlorella oil hydrolysates. Thereby, this study may contribute to biosynthesis of medium chain fatty acids from microalgae oils as well as long chain fatty acids.

• The Korea Journal of Herbology
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• v.27 no.1
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• pp.35-39
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• 2012

Objectives : The purpose of this study was to investigate the changes in the contents of constituents in Samultang and its fermentations with 10 species of lactic acid bacteria. Methods : Ten strains of lactic acid bacteria, Lactobacillus casei, L. acidophilus, L. casei, L. plantarum, L. amylophilus, L. curvatus, L. delbruekil subsp. lactis, L. casei, B. breve, and B. thermophilum, were used for the fermentation of Samultang. The increased and decreased constituents were identified using HPLC/DAD and various liquid chromatographic techniques, and the structure was elucidated using NMR and MS. These compounds were quantitatively analyzed using an HPLC/DAD system. Results : A remarkably increased component was identified to be nodakenetin and a decreased component was determined to be nodakenin. The fermentation of the ten lactic acid bacteria demonstrated that the decomposable rate of these two compounds in fermented Samultang were different. Samultang fermented by L. plantarum showed the most remarkable changes. Conclusion : Nodakenetin was identified as bioconversion component after fermentation and L. plantarum was discovered the best bacteria to increase the component.

• The Journal of the Korean Society for Microbiology
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• v.16 no.1
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• pp.35-38
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• 1981

Lactobacillus species isolated from posterior fornix of the vagina of 410 Korean women, who visited several local clinics and the Family Health Clinic of the Institute of Reproductive Medicine and Population, Seoul National University in Seoul were identified by their physiological and biochemical characteristics. And the results were as follows. 1) Of the 410 women 297(72.4%) gave the positive culture for Lactobacillus. 2) Isolated 200 strains were differentiated into following species. L. salivarius(43 strains, 18.7%) and L. leichmannii(42, 18.3%) were the most common species followed by L. plantarum(34, 14.8%) L.brevis(22, 9.6%), L. fermenti(19, 8.3%), L. cellobiosus(15, 6.5%), L. acidophilus(14, 6.1%), L. delbrueckii(10, 4.3%) and L. casei(1, 0.4%) and there were 30 strains(13%) which could not have been identified by the methods employed in this study. 3) Age seems to have no influence on the distribution of Lactobacillus species in vagina and it seems like that the overall distribution of Lactobacillus species in vagina does not change during the active reproductive period of women.

• The Korean Journal of Food And Nutrition
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• v.25 no.2
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• pp.291-298
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• 2012

One of the main microorganisms causing diarrheal diseases is Campylobacter jejuni. Purslane or Portulaca oleracea is an edible plant containing polyphenols that has been widely used as a folk remedy for treatment of diarrhea for a long time. This study was performed to investigate the antimicrobial activity of fermented P. oleracea extracts made with probiotics and plant-origin lactic acid bacteria(PLAB) isolated from P. oleracea against C. jejuni. Lactobacillus rhamnosus, L. acidophilus, L. bulgaricus, L. delbrueckii, L. plantarum, Leuconostoc mesenteroides and Bifidobacterium longum were applied to P. oleracea to make a fermentation broth of purslane. Leuconostoc mesenteroides and the lactic acid bacteria isolated from P. oleracea grew best in the fermentation broth of P. oleracea extracts when the broth was combined with 2% yeast extract, 1% peptone, and 0.05 to 1% potassium phosphate. The number of viable cells in the fermentation broth containing purslane extracts after 48 hours increased to $1{\times}10^{12}\;CFU/m{\ell}$ and remained at $1.3{\times}10^{10}\;CFU/m{\ell}$ after refrigeration for 2 weeks. The pH and acidity of purslane-fermented broth after 48 hours of fermentation was 3.7 and 3.14, respectively, which show that the fermentation broth was within the range of the general standards of fermented dairy products. The antimicrobial activity of the fermented P. oleracea extracts was determined using the liquid culture method. The 10 $mg/m{\ell}$ concentration of the fermented P. oleracea extract made with Leuconostoc mesenteroides and the lactic acid bacteria isolated from purslane showed the strongest antimicrobial activity against C. jejuni. The fermentation broth of purslane with the probiotics retarded the growth of C. jejuni for 48 hours at $42^{\circ}C$.

• Food Science of Animal Resources
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• v.26 no.1
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• pp.106-112
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• 2006

Fifty four acid-resistant and bile-resistant isolates of lactic acid bacteria were initially isolated from the faces of Korea native cattle and Holstein using MRS agar and LAPT agar, and ten strains with superior activity against bile salt were finally selected LS1, LS15, and LL6 isolates showed survival of 66.5%, 82.6% and 80.7% against the simulated stomach liquid(pH 2.5), respectively. LL6 and LL7 isolates had the highest inhibitory activities against the pathogenic bacteria such as Salmonella typhimurium, Staphylococcus aureus, and Clostridium perfringens. By using API 50 CHL kit LS1, LS2 and LM1 isolates were identified as a L. fermentum. LL6 and LL7 isolates as a L. acidophilus, and LS3 isolate as a L. plantarum. The other four isolates belong to genus Lactobacillus. All the isolates tested were sensitive to some antibiotics such as ampicillin, amoxicillin and erythromycin, but resistant to colistin and ciprofloxacin. LB1, LL6 and LL7 isolates were resistant to gentamicin and neomycin. Especially, the LL6 isolate showed the highest resistance to both of the simulated stomach liquid and bile salt, in addition to the highest inhibitory activities against Sal. typhimurium, Staph. aureus and Cl. perfringens.

• Journal of Applied Biological Chemistry
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• v.54 no.1
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• pp.51-55
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• 2011

To develop a health-aid preparation of Dioscorea batatas (DB), lactic acid fermentation was attempted using a mixed starter comprising of Lactobacillus acidophilus, Lactobacillus plantarum, Bifidobacterium longum. The anaerobic fermentation of a 10% DB flour suspension gave a uniform suspension of pH 3.65, containing $8{\times}10^6$ CFU/mL lactic acid bacteria. During the administration of the lactic acid fermented DB (FDB) and DB to trinitrobenzene sulfonic acid (TNBS)-induced colitis mouse model, histological lesions, morphological damage, and myeloperoxidase acitivity were significantly reduced at a dosage of 200 and 400 mg/kg/day. Dose-response (200 and 400 mg/kg/day) studies revealed that FDB pre-treatment of mice significantly ameliorated the appearance of diarrhoea and the disruption of colonic architecture. In FDB-pretreated mice, there was a significant reduction in the degree of both neutrophil infiltration (measured as decrease in myeloperoxidase activity) and weight loss rates. Theses findings suggest that FDB exerts beneficial effects in experimental colitis and may be useful in the treatment of inflammatory bowel disease.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.357-362
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• 1990

Soy yoghurt was prepared from 19 soybean cultivars with the use of L. acidophilus KCTC 2182. Various characteristics of fermented soymilk and the ratio of product recovery in soy yoghurt were investigated The mean crude protein content of the soy yoghurt was 2.74% with a range of 2.58-2.91% and the mean crude fat content was 1.49% with a range of 1.34-1.85%. Total solids recovered from original soybean in soy yoghurt ranged 52.14-61.54% with a mean value of 56.17%. Crude protein recovery in soy yoghurt ranged 59.22-67.5% with a mean value of 63.32%, Crude fat ranged 65.8-86.02% with a mean value of 72.57%. Titratable acidity of soy yoghurt ranged 0.20-0.41%. Viable cell count of soy yoghurt ranged $3.83{\times}10^8-3.22{\times}10^9/ml$ and the amount of separated whey ranged 1.4-8.2ml per 100ml of soymilk.