• Korean Journal of Microbiology
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• v.55 no.3
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• pp.258-267
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• 2019

The purpose of this study was to investigate the effect of lactic acid bacteria (LAB) on the growth and biogenic amines (BA) formation of Enterobacter aerogenes CIH05 in skim milk and soymilk. Lactobacillus acidophilus GK20, Lactobacillus paracasei GK74, and Lactobacillus plantarum GK81 isolated from mustard kimchi did not produce BA in the decarboxylation broth. L. paracasei GK74 exhibited the highest cell viability and antimicrobial compounds producing ability in fermented skim milk and soymilk samples, while the lowest producer was L. plantarum GK81. The production yield of lactic acid, hydrogen peroxide, and bacteriocin was dependent on the species of Lactobacillus and the type of culture medium. As LAB the number of viable cells of E. aerogenes CIH05 were higher in skim milk than in soymilk. When mixed culture with L. acidophilus GK20 and L. paracasei GK74 and treated with bacteriocin solution (300 AU/ml) obtained from these strains in milk media, the cell growth and cadaverine and histamine contents of E. aerogenes CIH05 were significantly (P < 0.05) lower than the respective values in control sample.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.5
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• pp.733-741
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• 2021

Jeju island is the largest island of South Korea, and has a relatively warm climate due to its geographical characteristics. These features have fostered development of various fermented foods distinct to Jeju island. Therefore, the functional activity of the lactic acid bacteria (LAB) isolated from the Jeju region's traditional fermented foods, including Kimchi and Jeotgal was characterized in this study. Fifteen strains were isolated from 6 types of fermented food. These strains include Enterococcus spp., Lactoplantibacillus spp., and Weisella spp. Several experiments were carried out to assess functional characteristics including acid resistance, bile resistance, hemolysis, DPPH and ABTS radical scavenging activity, and cholesterol-lowering activity. Three isolated strains (J-4, J-6 and J-10) exhibited high acid resistance, while the other 3 isolates (J-1, J-4 and J-6) showed high bile salt resistance. The strains displayed varied DPPH and ABTS radical scavenging activity: 71.14-86.42% among the first 3 strains, and 50.11-75.11% among the remaining 3 strains. Cholesterol-lowering activities were in the range 15.74-82.90% for all isolated strains. In conclusion, these studies suggest that isolated LAB strains from Jeju island traditional fermented foods possess the potential for broader application in the food industry.

• Journal of Microbiology and Biotechnology
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• v.19 no.2
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• pp.178-186
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• 2009

To examine their potential as probiotics, acid and bile tolerance, antibiotics resistance, adhesion capacity to Caco-2 and HT-29, and antibacterial activity, of LAB isolated from Korean fermented foods such. as dongchimi, kimchi, Meju, and doenjang were assayed against foodborne pathogenic bacteria. DC 55, DC 136, DC 222, KC 21, KC 24, KC 34, KC 43, KC 117, MJ 54, MJ 301, SP 33, and SP 170 strains were resistant to acid and bile conditions. In particular, DC 55, DC 136, KC 24, KC 43, and MJ 301 strains were highly resistant to higher than 20 ${\mu}g/ml$ concentrations of vancomycin, streptomycin sulfate, or amoxicillin, whereas, DC 222, KC 21, KC 34, KC 117, MJ 54, and SP 33 strains were susceptible to lower than 2 ${\mu}g/ml$ concentrations of those antibiotics. The adhesion to HT-29 and Caco-2 cells varied with the strains tested in a strain-dependent manner. The highest level of adhesion was observed with DC 55, KC 21, KC 24, and MJ 301 strains, having higher than 50% of adhesion to HT-29 or Caco-2 cells. In addition, Staphylococcus aureus was the most sensitive to KC 21, showing an inhibition of about 70%, and the antibacterial activity of KC 21 against S. aureus resulted most likely from both organic acids and bacteriocin. Based on its phenotypic characteristics and utilization of various sugars, the KC 21 strain was identified as Lactobacillus plantarum.

• Journal of Community Nutrition
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• v.4 no.3
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• pp.164-179
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• 2002

A survey was conducted to examine the food intake of 285 Korean female students attending a secondary school in Seoul. Food intake was assessed using a food frequency based on the Korean Food Tower which consists of five food groups, i.e., grain products, vegetables and fruits, meat, milk, and fats and sweets. To describe food intake descriptive statistics were obtained using SPSS. The food frequency analysis indicated that the participants ate rice, cabbage kimchi, radish, and soybean/red pepper paste most frequently along with milk, ice cream, tea, and seasonal fruits such as citrus fruits, apples, watermelon, and grapes for snacks. Distributions of the total standardized serving frequency for each food group indicated that approximately 84, 83, 45, 60, and 34%, respectively, of the respondents met the recommended serving frequency for grain products, vegetables and fruits, meat, milk, and fats and sweets groups(mean servings per day 5.5, 10.6, 5.5, 2.1, 3.5). Income was the only demographic factor that affected food intake, particularly with respect to meat, milk, and fats and sweets(p < .01). In Korea, these food groups are generally more expensive than the other ones. (J Community Nutrition 4(3) : 164∼179, 2002)

• Microbiology and Biotechnology Letters
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• v.37 no.4
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• pp.389-398
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• 2009

Development of expression vectors is important for the basic and applied researches on kimchi LAB (lactic acid bacteria). An expression vector, pSJE6c was constructed by inserting P6C promoter sequence from Lactococcus lactis into pSJE, a shuttle vector for E. coli and Leuconostoc species. To test the efficiency of pSJE6c, aga ($\alpha$-galactosidase) and lacZ ($\beta$-galactosidase) genes were expressed in Lactobacillus brevis 2.14. Compared to the pSJE, expression levels of both genes were increased, indicating P6C promoter was better than indigenous promoters. Enzyme activities of L. brevis cells harboring pSJE6caga (pSJE6c with aga) or pSJE6Z (pSJE6c with lacZ) were 1.5-2 fold higher than those with pSJEaga (pSJE with aga) or pSJEZ (pSJE with lacZ). More RNA transcripts were detected in cells harboring pSJE6c based recombinant plasmid. The results indicated that heterologous gene expressions in kimchi LAB could be improved significantly by use of efficient expression vectors.

• Food Science of Animal Resources
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• v.29 no.5
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• pp.640-646
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• 2009

Lactic acid bacteria (LAB) are typical probiotic microbes that are used in various industries including fermented foods, feed additives, and pharmaceuticals. The purpose of this study was to compare the ability of isoflavone biotransformation and antioxidative activity of 17 LAB. Six strains including the Lactobacillus species exhibited a 100% hydrolysis rate for daidzein during fermentation. The content of total genistein in soymilk fermented with these strains was $872-943\;{\mu}g/g$. The DPPH (1, 1-diphenyl-2-picrylhydrazyl) radical scavenging ability of the LAB was widely variable and ranged from 23-78%. A selected strain was isolated from kimchi and the strain was identified as Lactobacillus plantarum ssp. through the API carbohydrate fermentation pattern and 16S rDNA profile. The strain exhibited excellent acid tolerance in an artificial gastric solution. L. plantarum YS712 showed high $\beta$-glucosidase activity in fermentation. The concentration of genistein and daidzein in soymilk fermented with L. plantarum YS712 increased from 3.64 to $917.3\;{\mu}g/g$ and from 58.18 to $1062.17\;{\mu}g/g$, respectively. These results demonstrate the potential of L. plantarum YS712 as a probiotic culture that can be utilized in the manufacturing of fermentation foods and dietary supplements.

• Journal of Environmental Science International
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• v.25 no.6
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• pp.789-798
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• 2016

Lactic acid bacteria (LAB) are industrially important microorganisms for probiotics. The recent widespread application of LAB for preparation of functional food is attributable to the accumulating scientific evidence showing their beneficial effects on human health. In this study, we isolated and characterized plant-derived LAB that show angiotensin-converting enzyme (ACE) inhibitory and antioxidant activities. The selected strain K2 was isolated from Kimchi, and identified as Lactobacillus plantarum by 16S rRNA gene analysis. The strain grew under static and shaking culture systems. They were also able to grow in different culture conditions like $25^{\circ}C{\sim}37^{\circ}C$ temperature, 4~10 pH range and ~6% NaCl concentration. L. plantarum K2 was highly resistant to acid stress; survival rate of the strain at pH 2.5 and 3 were 80% and 91.6%, respectively. The strain K2 also showed high bile resistance to 0.3% bile bovine and 0.3% bile extract with more than 74% of survival rate. The cell grown on MRS agar plate containing bile extract formed opaque precipitate zones around the colonies, indicating they have bile salt hydrolase activity. The strain showed an inhibitory activity against pathogenic bacteria such as Escherichia coli, Staphylococcus aureus and Listeria monocytogenes; antibacterial activity was probably due to the lactic acid. The K2 strain showed relatively higher autoaggregation values, antihypertensive and antioxidant activities. These results suggest that L. plantarum K2 could be not only applied as a pharmabiotic for human health but also is also starter culture applicable to fermentative products.

• The Korean Journal of Food And Nutrition
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• v.29 no.5
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• pp.698-705
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• 2016

This study aimed to evaluate the quality characteristics of Gastrodia elata Blume fermented by lactic acid bacteria after saccharifying by 3 methods including enzyme, malt, and rice-nuruk. The lactic acid bacteria (LAB), Pediococcus inopinatus BK-3, isolated from kimchi could reduce the unpleasant taste and odor of Gastrodia elata Blume. The total acidity value of Gastrodia elata fermented by LAB on the malt and rice-nuruk extract solution for 3 days was 2.23% and 2.33%, respectively. After saccharification by malt and rice-nuruk extract solution for 3 days, the viable cell number of fermented Gastrodia elata was 9.14 log cfu/mL and 9.27 log cfu/mL, respectively. The total acidity values were increased above 3.35% by malt and rice-nuruk extract solution for 8 days. Thus, the viable cell number was the highest by malt and rice-nuruk extract solution fermentation for 3 days. The amino acid content of Gastrodia elata fermented by LAB after saccharification by malt extract solution was higher than that of other saccharifying methods. The free sugar content and p-hydroxybenzyl derivatives induced by the enzyme method were higher than those of other saccharifying methods. The overall acceptability was the highest at 4.2 point in Gastrodia elata fermented by malt extract solution.

• Journal of Food Hygiene and Safety
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• v.35 no.6
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• pp.618-629
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• 2020

The purpose of this study was to optimize the fermentation condition of black bean by lactic acid bacteria (LAB) and to evaluate the quality characteristics of fermented black bean. Lactobacillus plantarum SU22 isolated from kimchi was selected as a starter for the fermentation of black bean because the strain exhibited strong antimicrobial activity against pathogenic bacteria and did not produce biogenic amines or a carcinogenic enzyme, β-glucuronidase. Fermentation was performed with broth containing puffed black bean (PBB) inoculated with 1% (v/v) of L. plantarum SU22 at 37℃ for 48h. The viable cell count of LAB was over 9 Log CFU/mL in PBB (20%) broth fermented with L. plantarum SU22. Fermentation of alcalase-treated PBB (20%) broth with L. plantarum SU22 was found to be the optimal condition, increasing viable cell count of LAB up to 10.30 Log CFU/mL. Under the optimal condition, the total polyphenol content (94.02 mg GAE/g) and DPPH radical scavenging activity (92.50%) were significantly increased, compared to non-fermented control (87.74 mg GAE/g, 83.14%).

• Korean Journal of Microbiology
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• v.46 no.4
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• pp.375-382
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• 2010

In present study, five strains of Lactobacillus acidophilus GK20, Lactobacillus brevis GK55, Lactobacillus paracasei GK74, Lactobacillus plantarum GK81, and Leuconostoc mesenteroides GK104 isolated from the mustard leaf kimchi were investigated for resistance to reactive oxygen species (ROS) and antioxidant activity. L. acidophilus GK20, L. brevis GK55, L. paracasei GK74, and L. plantarum GK81 were resistant to hydrogen peroxide (0.5 mM), showing a survival rate of 50% or more. In particular, L. acidophilus GK20 and L. paracasei GK74 were the most superoxide anions-resistant and L. paracasei GK74 and L. plantarum GK81 were most likely survive hydroxyl radicals. Meanwhile, the intracellular cell-free extract (ICFE) from L. plantarum GK81 exhibited significantly higher DPPH radical scavenging values ($96.4{\pm}2.8%$) than the intact cells (IC). The ICFE of L. plantarum GK81 showed the highest superoxide radical scavenging ability and chelating activity for $Fe^{2+}$ ions among the 5 lactic acid bacteria (LAB) tested, and IC and ICFE from L. plantarum GK81 demonstrated excellent reducing activity, which was higher than those of BHA and vitamin C as a positive control.