• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1148-1161
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• 2016

Lactobacilli are universally recognized as probiotics that are widely used in the adjuvant treatment of inflammatory diseases, such as vaginitis and enteritis. With the overuse of antibiotics in recent years, the lactobacilli in the human body are killed, which could disrupt the microecological balance in the human body and affect health adversely. In this work, cephalosporin-resistant Lactobacillus casei RL20 was obtained successfully from the feces of healthy volunteers, which possessed a stable genetic set. However, the shortage of lactic acid (72.0 g/l at 48 h) by fermentation did not meet the requirement for its use in medicine. To increase the production of lactic acid, the functional genes pfk and glk were introduced into the wild strain. A yield of 144.2 g/l lactic acid was obtained in the transgenic L. casei RL20-2 after fermentation for 48 h in 1 L of basic fermentation medium with an initial glucose concentration of 100 g/l and increasing antibacterial activity. These data suggested that L. casei RL20-2 that exhibited a high yield of lactic acid may be a potential probiotic to inhibit the spread of bacterial infectious diseases and may be used for vaginitis therapy.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.64-68
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• 2013

Previous studies have shown that lactic acid bacteria can inhibit inflammatory responses, but the mechanisms are very little known. In this study, transaction and expression of three proinflammatory factors, iNOS, PTGS-2, and IL8, which are closely related to the inflammatory response, were investigated by luciferase reporter assay and RTPCR in HT-29 cells treated by Lactobacillus acidophilus. The results showed that the live L. acidophilus sharply down-regulated the transcription of these three genes. Because there was a NF-${\kappa}B$ binding site located at -265 bp, -225 bp, and -95 bp upstream of the iNOS, PTGS-2, and IL8 promoters, respectively, we further addressed the effects of NF-${\kappa}B$ on transaction of the three promoters by cotransfection. As was expected, NF-${\kappa}Bs$ remarkably upregulated the activity of the reporter gene and, no effect of NF-${\kappa}B$s on IL-8 promoter transaction was found after NF-${\kappa}B$ binding site mutation of the IL8 promoter in HT-29 cells. In conclusion, the live L. acidophilus decreased the transcriptional activity of NF-${\kappa}B$ and, in turn, inhibited the transaction of NF-${\kappa}B$ on the three proinflammatory factors mentioned above.

• Journal of Food Hygiene and Safety
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• v.36 no.5
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• pp.440-446
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• 2021

GABA (γ-aminobutyric acid) has various beneficial effects on human health such as anti-hypertension, diuretic, tranquilizer, sleep induction and anti-stress functions. In this study, the properties and the antioxidizing effects of a fermented solution was investigated by applying GABA producing lactic acid bacteria (LAB) from kimchi to corn silk extract. Lactobacillus plantarum LAB459 was identified by physiological properties, carbohydrate fermentation pattern and 16s rRNA sequence analysis. Also, the GABA production ability of the separated L. plantarum LAB459 was confirmed through TLC and HPLC analysis. Moreover, from the fermentation of corn silk extract with skim milk, it was revealed that approximately 1 ㎍/mg of GABA produced by lyophilized ferments was yielded. Lastly, the flavonoid content and DPPH radical scavenging activity were found to be high in the lyophilized ferments than in the aqueous extracts. Therefore, L. plantarum LAB459 is considered to be used as a starter culture for various fermented foods or in food and medicinal materials.

• Journal of Microbiology and Biotechnology
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• v.5 no.6
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• pp.309-314
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• 1995

Samples were collected from a commercial ethanol production plant to enumerate the bacterial contamination in each step of a starch based ethanol production process. Though the slurry of raw material used in the process carried bacteria with various colony morphology in the order of $10^4$ per ml, only the colonies of white and circular form survived and propagated through the processes to the order of $10^8$ per ml at the end of fermentation. Almost all of the bacterial isolates from the fermentation broth were lactic acid bacteria. Heterofermentative Lactobacillus fermentum and L. salivarius, and a facultatively heterofermentative L. casei were major bacteria of an ethanol fermentation. In a batch fermentation L. fermentum was more detrimental than L. casei to ethanol fermentation. In a cell-recycled fermentation, ethanol productivity of 5.72 g $I^{-1} h^{-1}$ was obtained when the culture was contaminated by L. fermentum, whilst that of the pure culture was 9.00 g $1^{-1} h^{-1}$. Similar effects were observed in a cell-recycled ethanol fermentation inoculated by fermentation broth collected from an industrial plant, which showed a bacterial contamination at the level of 10$^8$ cells per ml.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.11
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• pp.1562-1570
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• 2014

The effects of Lactobacillus mucosae (L. mucosae), a potential direct fed microbial previously isolated from the rumen of Korean native goat, on the rumen fermentation profile of brewers grain were evaluated. Fermentation was conducted in serum bottles each containing 1% dry matter (DM) of the test substrate and either no L. mucosae (control), 1% 24 h broth culture of L. mucosae (T1), or 1% inoculation with the cell-free culture supernatant (T2). Each serum bottle was filled anaerobically with 100 mL of buffered rumen fluid and sealed prior to incubation for 0, 6, 12, 24, and 48 h from which fermentation parameters were monitored and the microbial diversity was evaluated. The results revealed that T1 had higher total gas production (65.00 mL) than the control (61.33 mL) and T2 (62.00 mL) (p<0.05) at 48 h. Consequently, T1 had significantly lower pH values (p<0.05) than the other groups at 48 h. Ammonia nitrogen ($NH_3$-N), individual and total volatile fatty acids (VFA) concentration and acetate:propionate ratio were higher in T1 and T2 than the control, but T1 and T2 were comparable for these parameters. Total methane ($CH_4$) production and carbon dioxide ($CO_2$) were highest in T1. The percent DM and organic matter digestibilities were comparable between all groups at all times of incubation. The total bacterial population was significantly higher in T1 (p<0.05) at 24 h, but then decreased to levels comparable to the control and T2 at 48 h. The denaturing gradient gel electrophoresis profile of the total bacterial 16s rRNA showed higher similarity between T1 and T2 at 24 h and between the control and T1 at 48 h. Overall, these results suggest that addition of L. mucosae and cell-free supernatant during the in vitro fermentation of dried brewers grain increases the VFA production, but has no effect on digestibility. The addition of L. mucosae can also increase the total bacterial population, but has no significant effect on the total microbial diversity. However, inoculation of the bacterium may increase $CH_4$ and $CO_2$ in vitro.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.8
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• pp.1292-1300
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• 2020

Objective: To explore feed resources capable of replacing regular poor-quality fodder, this study was conducted to evaluate the effects of additives on the fermentation quality, in vitro digestibility and aerobic stability of mulberry leaves silage. Methods: The mulberry leaves were ensiled either untreated (control) or treated with 1×10⁶ cfu/g fresh matter Lactobacillus plantarum (L), 1% glucose (G), 3% molasses (M), a combination of 1% glucose and Lactobacillus plantarum (L+G), and a combination of 3% molasses and Lactobacillus plantarum (L+M). The fermentation quality and chemical composition were analyzed after 7, 14, 30, and 60 d, respectively. The 60-d silages were subjected to an aerobic stability test and fermented with buffered rumen fluid to measure the digestibility. Results: Inoculating lactic acid bacteria (LAB) resulted in more rapid increase in lactic acid concentrations and decline in pH of mulberry leaves silage as compared control. Higher acetic acid and lower ethanol and ammonia nitrogen concentrations (p<0.05) were observed in the LAB-inoculated silages as opposed to control during ensiling. The LAB-inoculated silages contained lower water-soluble carbohydrates compared with control during the first 14 d of ensiling, and lower neutral detergent fibre (p<0.05) concentrations as compared with non-LAB inoculated silages. Adding molasses alone increased (p<0.05) the digestibility of dry matter (DM). The aerobic stability of mulberry leaves silage was increased by LAB inoculation, whereas decreased by adding glucose or molasses. Conclusion: The LAB inoculation improved fermentation quality and aerobic stability of mulberry leaves silage, while adding glucose or molasses failed to affect the fermentation and impaired the aerobic stability. Inoculating LAB alone is recommended for mulberry leaves especially when ensiled at a relatively high DM.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.1
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• pp.95-102
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• 2012

The purpose of this study is to investigate antioxidant properties in microbial fermentation products of Lonicera japonica Thunb extract. The bacterium Lactobacillus plantarum NHP1 was isolated from conventional fermented foods. Modern pharmacological studies show that Lonicera japonica Thunb and its active principles of wide pharmacological actions. For instance, they show a strong efficacy in antibacterial, anti-inflammatory, antiviral, anti-endotoxin, blood fat reducing, antipyretic, and antioxidant activities. The extract of Lonicera japonica Thunb was obtained by extracting dried Lonicera japonica Thunb using either hot water or 70% ethanol as a solvent. Fermentation was performed in a 2L fermentor containing 1.2 L of extractat conditions of $30^{\circ}C$ and 100 rpm for 48 hr. The amount of cholorogenic acid was $2.65{\mu}g/g$ in hot water extract. The total phenolic content (GAE, gallic acid equivalent) in hot water and 70% ethanol were $56.5{\pm}4.9$ GAE mg/g and $72.7{\pm}5.3$ GAE mg/g, respectively. After fermentation, the phenolic content increased to 30.2% in hot water and 12.9% in ethanol extract. In the same manner, flavonoid content increased to more than 75% regardless of extract solvent. ABTS (2,2-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid) value noticeably increased to 50% after fermentation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1467-1474
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• 2013

To develop a starter culture system for the fermentation of mukeunji, we introduced lactic acid bacteria and yeast isolated from mukeunji into kimchi fermentation as a single or a mixed culture. On evaluating mukeunji flavor, we found that the mixed starter kimchi prepared with two strains, ML17 and MY7, gave the best sensory score. These strains were identified as Lactobacillus (Lb.) curvatus ML17 and Saccharomyces (S.) servazzii MY7 by molecular identification method. The fermentative characteristics of starter kimchi were investigated by measuring changes in the physicochemical and microfloral characteristics during the fermentation. The decrease in pH and increase in acidity in the starter kimchi were faster compared to respective values of control kimchi. There was a gradual decrease in hardness of starter kimchi, which was still slow compared to hardness decrease in control kimchi. Microbial analysis of starter kimchi revealed that Lb. curvatus ML17 and S. servazzii MY7 were the dominant organisms during the entire fermentation period. The lactic acid and citric acid contents of starter kimchi were higher than those of the control kimchi after 90 days of fermentation. By sensory evaluation, the starter kimchi scored higher in appearance, mukeunji flavor, sourness, carbonated flavor, savory taste, texture, and overall acceptability, but lower in off-flavor than the control kimchi.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.6
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• pp.787-794
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• 2009

In this study, a new method for extending storage-life and palatability of Betula platyphylla sap by applying lactic acid bacteria fermentation was developed. The fluids of saps were filtered through 0.22 ${\mu}m$ membrane filter and each fermented by 8 different lactic acid bacteria which are Lactobacillus acidophilus, Lactobacillus brevis, Leuconostoc mesenteroides, Leuconostoc lactis, Lactococcus lactis, Pediocossus pentosaceus, Pediococcus dextrinicus, Streptococcus thermophilus. All the tested lactic acid bacteria except P. dextrinicus grew fast up to $10^6{\sim}10^7cfu/mL$ levels and lowered pH down to about pH 4 levels in 48 hours in both saps. The produced organic acids and lowered pH level inhibited the growth of spoilage microorganisms almost completely for 2 weeks during storage at room temperature. Addition of xylitol in the saps before fermentation accelerated the growth of lactic acid bacteria and increased the sweetness and overall taste of final product. The filtration process did not affect the mineral compositions of Betula platyphylla saps. Also the compositions and amounts of minerals showed very minor differences before and after fermentation in Betula platyphylla saps inoculated with L. acidophilus. By applying lactic acid fermentation to extend storage-life of tree saps instead of heat treatment, it was possible to keep natural minerals in active forms without any modifications.

• Korean Journal of Food Science and Technology
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• v.50 no.6
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• pp.572-580
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• 2018

Biologically active substances including gamma-aminobutryric acid (GABA) were added into whey by co fermentation using Bacillus subtilis HA and Lactobacillus plantarum EJ2014. The first fermentation using B. subtilis HA with 5% monosodium glutamate (MSG) and 2% glucose enhanced the production of poly-${\gamma}$-glutamic acid (PGA), resulting in higher consistency of $4.09Pas^n$ as well as whey protein peptides. After the second fermentation using L. plantarum EJ2014, the remaining MSG (3.40%) as a precursor was completely converted to 2.21% GABA. Furthermore, the lactose content in whey decreased from 6.73 to 3.68% after co-fermentation, and the tyrosine content increased from 20.47 to 38.24%. Peptides derived of whey proteins were confirmed by SDS-PAGE. Viable cell counts of B. subtilis and L. plantarum were 5.83 log CFU/mL and 9.20 log CFU/mL, respectively. Thus, co-fermentation of whey could produce the novel food ingredient fortified with biologically active compounds including GABA, ${\gamma}$-PGA, peptides, and probiotics.