• Journal of Life Science
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• v.12 no.6
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• pp.812-820
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• 2002

In order to understand stress response of Leuconostoc mesenteroides against lactic acid, a new Leuconostoc sp. which has acid tolerance was isolated from various Kimchi samples. And it identified as Leuconostoc mesenteroides LM3 by comparing its fatty acid composition with reference strain. Its growth pattern was investigated by adding a given concentration of lactic acid at the lag phase to the stationary phase. In the DeMan, Rogosa, Sharpe (MRS) media containing over 0.4% (final v/v) lactic acid, this strain slowed slowly After exposure of the stationary phase cells to 4% of lactic acid for 60 min, this strain could survive, whereas a reference strain, Leuconostoc mesenteroides KCTC3505, showed no survival. And changes of trehalose concentration, the activity of trehalase and ATPase in the growth of Leuconostoc mesenteroides LM3 after addition of 0.6% (final v/v) lactic acid were investigated : After exposure to lartic acid, trehalose concentration in this strain was increased in comparison with no treatment, but its trehalase activity was not changed. And its ATPase activity was constant, and intracellular pH was almost constant. This result meant Leuconostoc mesenteroides LM3 should have a tolerance against lactic acid. It remains to further study the mechanism of this acid tolerance.

• Journal of the East Asian Society of Dietary Life
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• v.11 no.5
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• pp.379-385
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• 2001

The effects of lactic acid bacteria from kimchi fermentation, specifically Lactobacillus plantarum(LP) and Leuconostoc mesenteroides (LM) on the quality of the bread product was investigated. The two types of bacteria were cultivated in the sterilized radish juice used for kimchi fermentation. The concentration of bacteria was measured at 3.0$\times$10$^{9}$ ~3.3$\times$10$^{9}$ /mL. The bacteria were added at the ratios of 5% and 10% to a mixture with wheat flour before subsequent dough fermentation. An LM+LP treatment to the mixture was also made at 5% of LP and 5% of LM. The measured pH in the dough with LM+LP was the lowest among all of treatments. The products of 5% LM treatment showed the shortest fermentation time. Loaf production by volume was the highest from the 10% LM treatment. The % of moisture loss of the bread during the shelf-storage was less when treated with lactic acid bacteria than when left untreated. The least moisture loss was observed when the bread was treated with the LM+LP mixture. Hardness of the bread also decreased with the presence of lactic acid bacteria. The order of hardness was: control > 5% LP > LM+LP > 5% LM > 17% LM > 10% LP. Staling degree of the bread when treated with lactic acid bacteria was lower than that of the control. The least staling occurred when treated with LM 10% and LP 10%.

• Journal of Microbiology and Biotechnology
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• v.31 no.8
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• pp.1144-1153
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• 2021

A released exopolysaccharide (rEPS)-producing strain (LM187) with good acid resistance, bile salt resistance, and cholesterol-lowering properties was isolated from Sichuan paocai and identified as Leuconostoc mesenteroides subsp. mesenteroides. The purified rEPS, designated as rEPS414, had a uniform molecular weight of 7.757 × 10⁵ Da. Analysis of the monosaccharide composition revealed that the molecule was mainly composed of glucose. The Fourier transform-infrared spectrum showed that rEPS414 contained both α-type and β-type glycosidic bonds. ¹H and ¹³C nuclear magnetic resonance spectra analysis showed that the purified rEPS contained arabinose, galactose, and rhamnose, but less uronic acid. Scanning electron microscopy demonstrated that the exopolysaccharide displayed a large number of scattered, fluffy, porous cellular network flake structures. In addition, rEPS414 exhibited strong in vitro antioxidant activity. These results showed that strain LM187 and its rEPS are promising probiotics with broad prospects in industry.

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.893-901
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• 2018

Influenza viruses that cause recurrent seasonal epidemics to humans can be controlled with vaccine and antiviral therapy. However, the medical treatments often exhibit limited efficacy in the elderly or immunosuppressed individuals. In these cases, daily uptake of probiotics may be an option to bring in health benefits against influenza. Here, we demonstrate the effects of probiotics Lactobacillus plantarum (Lp) and Leuconostoc mesenteroides (Lm) against seasonal and avian influenza viruses. As assessed by the plaque size reduction of human H1N1 and avian influenza H7N9 viruses, including green fluorescent protein-tagged H1N1 strain in cells, the selected Lp and Lm strains restrained viral replication in mouse lungs with statistical significance. Against lethal viral challenge, the Lp and Lm strains exhibited their beneficial effects by increasing the mean days and rates of survival of the infected mice. These results suggest that, despite rather narrow ranges of protective efficacy, the dietary supplement of Lactobacillus and Leuconostoc probiotics may promote health benefits against influenza.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1250-1259
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• 2018

In this study, Momordica charantia (MC) fermented with Leuconostoc mesenteroides (MC-LM) were assessed for the antioxidant and the antidiabetic activities. Antioxidant activities of MC and MC-LM were evaluated using 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)(ABTS) radical. Although MC-treated groups showed little activity, 47% of activity was observed at $500{\mu}g/mL$ concentration for MC-LM and increased significantly(p<0.05) as MC-LM concentration increased. MC-LM more effectively inhibited the oxidative damage of DNA by peroxyl radical than MC and the inhibition of the strand breakage increased significantly as MC-LM concentration increased(p<0.05). Measuring the inhibition of ${\alpha}-glucosidase$ activity, which is closely related to the regulation of blood sugar, resulted in MC reduced the activity of ${\alpha}-glucosidase$ by 30% at 8 mg/mL and MC-LM at the same concentration by 60%. In addition, the effect of MC-LM on the cell viability of alloxan-treated RIN-m5F resulted in a significant increase in cell survival(p<0.05) in the group treated with MC-LM and a 20% increase in the concentration of $1000{\mu}g/mL$. As a result of insulin secretion by alloxan-treated RIN-m5F cell, the level of insulin secretion tended to increase in all group treated with MC-LM. At the concentration of $1000{\mu}g/mL$, the insulin secretion was increased by 15% in MC-LM group than in MC group. In conclusion, the results of this study suggest that fermented bitter gourd has antioxidant and antidiabetic effects.

• Journal of Korean Medicine for Obesity Research
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• v.13 no.1
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• pp.17-23
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• 2013

Objectives: This study was performed to evaluate the effects of fermented Samjung-hwan (SJH) extracts on weight, serum lipids and blood glucose. Methods: SJH was fermented using three different probiotic bacterial strains (Lactobacillus plantarum [LP], Leuconostoc mesenteroides [LM], Bifidobacterium longum [BL]) separately. Thirty-six rats were divided into normal, control (high fat diet), SJH-UF (high fat diet+unfermented SJH 200 mg/kg), SJH-LP (high fat diet+LP fermented SJH 200 mg/kg), SJH-LM (high fat diet+LM fermented SJH 200 mg/kg) and SJH-BL (high fat diet+BL fermented SJH 200 mg/kg). For 8 weeks later, we examined body weight, total cholesterol, high-density lipoprotein (HDL)-cholesterol and blood glucose. Results: The control group showed significantly increased weight gain compared with normal group and SJH-LP and BL groups had less weight gain than control group, significantly. In the lipid serum tests, control group showed significantly increased total cholesterol levels compared with normal group and only SJH-LP represented decreased total cholesterol levels compared with control group. However there was no significant change in the HDL-cholesteol levels. In the blood glucose tests, that of control group significantly incereased more than that of normal group, SJH-BL showed significantly decreased blood glucose levels compared with control group. Conclusions: SJH-LP, SJH-BL showed weight control effect, SJH-LP decreased TC and SJH-BL reduced blood glucose.

• Microbiology and Biotechnology Letters
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• v.33 no.1
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• pp.41-50
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• 2005

An organic acid tolerance mutant (M-200) was obtained from Leuconostoc mesenteroides KCCM 35471, followed by the screening procedure using a specific organic acid medium (lactic acid: acetic acid, 2:1). The characteristics of the acid tolerance M-200 and the wild type LM-W were examined at various temperature and pH ranges $(l0-30^{\circ}C$ of temp, 3.5-4.5 of pH). The growth of strain M-200 at HCl adjusted medium $(10^{\circ}C\;and\;pH 3.5)$ was observed. In the case of organic acid adjusted medium, the strain showed its growth at the pH range of 3.8. When the strain M-200 was used as a starter for Kimchi fermentation, a constant acid level (0.55) was observed during the whole fermentation period. This result indicates that the strain produces a proper level of acid content for the Kimchi fermentation. This result also indicates that the edible period of Kimchi can be extended to 3.5 fold compare to the result obtained from the LM-W used Kimchi fermentation. However the excess use of the strain M-200 showed the inhibition of growth of Lactobacillus plantarum, low lactic acid level content and low level of organoleptic test. In the case of organic acid content during the Kimchi fermentation, the strain M-200 showed relatively low production rate compare to the wild type (M-200: 3.5 mg/L at 21 days of fermentation, LM-W: 7 mg/L at 21 days of fermentation). Therefore a mixed Kimchi starter containing M-200 and other strains probably maintain a good Kimchi quality during the fermentation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1854-1859
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• 2010

Three kinds of Korean traditional Meju were selected and the counts of microorganisms in these Meju were determined. The counts of total aerobic bacteria, lactic acid bacteria and yeasts and molds were 107~108, 106~108 and 107~108 cfu/g, respectively in three Meju and lactic acid bacteria were important microorganisms in the fermentation of Meju. Therefore, we isolated three kinds of dominant lactic acid bacteria from these Meju. They were identified as Leuconostoc mesenteroides (98%, Lm-SMm), Lactobacillus plantarum (99%, Lp-SMm) and Lactococcus lactis (98%, Ll-GAm). Then, enzyme activities and physiological functionalities of three lactic acid bacteria were investigated. Protease, lipase and $\alpha$-amylase activities were detected in three lactic acid bacteria, Ll-GAm showed relatively higher activities than other two lactic acid bacteria. Lm-SMm, Lp-SMm and Ll-GAm showed 45, 48 and 60% of antioxidative activity to 1,1-diphenyl-2-picryhydrazyl (DPPH), and exhibited 45, 67 and 70% of inhibitory effects in HT-29 human colon cancer cells, respectively. These results indicate that three lactic acid bacteria isolated from traditional Meju, especially Ll-GAm are applicable to Meju preparation for soybean paste industry.

• Food Science and Preservation
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• v.22 no.5
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• pp.758-767
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• 2015

Red pepper powder sensitive to aflatoxins contamination is major ingredients of kimchi. This study was conducted to investigate the effect of lactic acid bacteria (LAB) on the changes in aflatoxin levels during kimchi fermentation. Baechu kimchi was contaminated with aflatoxins ($B_1$, $B_2$, $G_1$, and $G_2$) and inoculated with LAB (Lactobacillus plantarum and Leuconostoc mesenteroides), and the following characteristics were investigated for 8 weeks: pH, titratable acidity, salinity, microbial properties, and aflatoxin levels. The pH decreased rapidly during storage, and the titratable acidity was increased. The salinity of the samples was shown to increase from 2.30 to 2.40%. The total number of aerobic bacteria and lactic acid bacteria in kimchi inoculated with LAB was significantly higher than that of the others. Yeast and molds were detected at approximately 1~3 log CFU/g during storage. Coliforms were detected in the control after 4 weeks, whereas in other samples they were not detected until after 2 weeks. The aflatoxin levels reduced during kimchi fermentation. The average reduction rate of aflatoxin levels during kimchi fermentation was 8.39%, but in kimchi inoculated with Lac. plantarum and Leu. mesenteroides, the rate were 25.16 % and 27.86%, respectively. These results showed that aflatoxins can be removed by LAB during kimchi fermentation.

• 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.