• Korean Journal of Microbiology
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• v.52 no.1
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• pp.84-97
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• 2016

Isolates from Korean fermented soybean paste were identified as Enterococcus faecium SBP12, Pediococcus halophilus SBP20, Lactobacillus fermentum SBP33, Leuconostoc mesenteroides SBP37, Pediococcus pentosaceus SBP41, Lactobacillus brevis SBP49, Lactobacillus acidophilus SBP55, and Enterococcus faecalis SBP58 according to conventional morphological and biochemical characteristics, carbohydrate fermentation profiling, and 16S rRNA sequence comparison. Strain SBP20, SBP33, SBP49, and SBP55 showed very resistance to simulated gastric and intestinal juices with final populations exceeding 6 log CFU/ml, whereas cells of SBP12 and SBP58 after exposure to low pH were dramatically decreased within 2 h. Among 4 strains having good tolerance to gastrointestinal conditions, the high adhesive ability to HT-29 cells, antibiotic resistance, and antimicrobial activity against food-borne pathogens Bacillus cereus ATCC 11778 and Staphylococcus aureus ATCC 6538 were observed with SBP49 and SBP55, therefore, these two strains were confirmed as putative probiotic candidates. There was no significant difference between the sourdoughs fermented with SBP49 and SBP55 with respect to the values of pH, total titratable acidity, and viable cell count. During sourdough fermentation, SBP49 strain produced significantly greater amounts of lactic acid than SBP55 strain, which secreted large quantities of hydrogen peroxide. SBP49 and SBP55 strains producing the antimicrobial substances such as lactic acid, hydrogen peroxide, and bacteriocin effectively inhibited B. cereus and S. aureus inoculated in the sourdough.

• Microbiology and Biotechnology Letters
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• v.38 no.2
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• pp.207-215
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• 2010

The purpose of this research is to draw the bacterial community difference between Korean and Chinese kimchi for future use in the confirmation of kimchi origin. Initial fermentation stage kimchi samples (above pH 5) were used for the analysis of bacterial diversity. From 26 Korean kimchi samples, 1,017 strains in the 45 genera and from 22 Chinese kimchi samples, 842 strains in the 54 genera were isolated with use of marine medium, nutrient medium, succinate minimal medium (SMM), leuconostocs selective medium (LUSM) agars. In the order of isolated numbers, Bacillus, Weissella, Leuconostoc, Pseudomonas, and Lactobacillus genera and Bacillus, Weissella, Lactobacillus, Pseudomonas, Serratia, and Enterobacter genera were predominated in Korean and Chines kimchi, respectively. Among the isolated lactic acid bacteria, Weissella spp. were isolated most dominantly owing to the biased growth of Weissella spp. on LUSM agar. Species in the genera Leuconostoc and Lactobacillus were the next frequently isolated LAB from Korean and Chinese kimchi, respectively. Weissella confusa was isolated only from Korean kimchi and W. soli and Serratia proteamculans were isolated only from Chinese kimchi. They have a possibility to be used as target bacteria to differentiate Korean kimchi from Chinese kimchi.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.2
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• pp.166-170
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• 2015

This study investigated the effect of novel Lactobacillus plantarum KCC-10 and KCC-19 on the quality and fermentation characterization of alfalfa silage at the experimental field of National Institute of Animal Science, Cheonan Province, Korea, from 2013 to 2014, and this experiment consisted of the following three treatments: control without lactic acid bacteria; treatment inoculated with L. plantarum KCC-10; and treatment inoculated with L. plantarum KCC-19. The contents of crude protein, acid detergent fiber, neutral detergent fiber, total digestible nutrient and in vitro dry matter digestibility of alfalfa silage were not affected by either L. plantarum KCC-10 or KCC-19. The pH of alfalfa silage in L. plantarum KCC-10 and KCC-19 treatments decreased as compared to control. The level of lactic acid in L. plantarum KCC-10 and KCC-19 treatments increased (p<0.05), whereas the contents of acetic acid and butyric acid decreased(p>0.05). In addition, the numbers of lactic acid bacteria in L. plantarum KCC-10 and KCC-19 treatments increased as compared to control (p<0.05). Therefore, these results suggest that the inoculation of L. plantarum KCC-10 and KCC-19 into alfalfa silage can improve the quality of silage through increased lactic acid content and lactic acid bacteria.

• Korean Chemical Engineering Research
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• v.53 no.1
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• pp.1-5
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• 2015

Lactic acid, the most widely occurring hydroxy-carboxylic acid, has traditionally been used as food, cosmetic, pharmaceutical, and chemical industries. Even though it has tremendous potential for large scale production and use in a wide variety of applications, high cost lactic acid materials are primarily problems. Lactic acid can be obtained on either by fermentation or chemical synthesis. In recent years, the fermentation approach has become more successful because of the increasing market demand for naturally produced lactic acid. Generally, lactic acid was produced from pure starch or from glucose. As an alternative, biomass which is the most abundant renewable resources on earth have been considered for conversion to readily utilizable hydrolysate. In this study, we conducted the fermentation method to produce L(+)-lactic acid production from pretreated hydrolysate was investigated by Lactobacillus rhamnosus ATCC 10863. The hydrolysate was obtained from pretreatment process of biomass using Ammonia percolation process (AP) followed by enzymatic hydrolysis. In order to effectively enhance lactic acid conversion and product yield, controlled medium, temperature, glucose concentration was conducted under pure glucose conditions. The optimum conditions of lactic acid production was investigated and compared with those of hydrolysate.

• Korean Journal of Food Science and Technology
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• v.48 no.6
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• pp.548-554
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• 2016

Since some strains of kimchi lactobacilli can curdle milk, they can be used for making yogurt. However, the best Lactobacillus plantarum strains for curdling milk for yogurt are still unknown. In this study, we determined the best L. plantarum strains for curdling milk, and the physicochemical properties of yogurts made using different L. plantarum strains were examined. Three strains of L. plantarum useful for curdling milk were identified (YD2, YD9, YD12). The number of lactobacilli was lower in yogurts made with L. plantarum than in those made with control, and among the L. plantarum strains tested, YD12 had the highest bacterial counts. However, the microbial count reached $6.3{\times}10^8CFU/mL$ after 24-h fermentation in all yogurts. The pH of the yogurts decreased after 12-h fermentation, while the acidity increased. The low pH and high acidity decreased the viscosity in all the three types of yogurts, because the acids disturbed gel formation due to protein denaturation. Sensory evaluation revealed that the YD12 group showed a high percentage of completion similar to the control group. YD2 and YD9 showed a high sourness value and low sweetness value, whereas YD12 yielded optimal values for all the organoleptic characteristics. Therefore, YD12 would be a high quality bacterial strain for use as a yogurt starter culture.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.179-185
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• 2018

In this study, the optimal fermenting conditions of sugar extracts of Artemisia annua L. (Aa), Houttuynia cordata Thunb (Hc), and Saururus chinensis Baill (Sc) were determined to develop fermented beverages. The sugar extracts ($50{\pm}5^{\circ}Bx$) were diluted to 10, 15, and $20^{\circ}Bx$, and fermented with 2% (v/v) of Lactobacillus plantarum DK119 ($5{\times}10^9CFU/mL$) at $37^{\circ}C$ for 4 days. According to the lactic acid bacteria population, pH, titratable acidity, and reducing sugar content, $20^{\circ}Bx$ for Aa, $10^{\circ}Bx$ for Hc and $15^{\circ}Bx$ for Sc were the maximum concentrations for the fermentation. There were no changes in total polyphenol content in the extracts of Aa, Hc, and Sc, whereas the radical scavenging activity and ferric reducing antioxidant power were increased during the fermentation. Lactic acid fermentation resulted in improvement of sensory evaluation scores on unfavorable plant taste and overall acceptability of the sugar extracts of medicinal plants.

• Food Science and Preservation
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• v.24 no.8
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• pp.1188-1194
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• 2017

Gochujang, a traditional Korean food, is fermented by mixing red pepper powder, various grain, meju and salt. Changes in the kind of ingredients and fermentation method could increase health functionalities. In this study, in vivo anti-colitis effects of gochujang prepared with mixed grains, bamboo salt baked 3 times and meju starters on DSS-induced colitis in C57BL/6 mice were studied. We prepared gochujang prepared with mixed grains (MG), bamboo salt, and Aspergillus oryzae (A) and Baccillus subtilis (B) mixed starters (MG-AB) and gochujang prepared with MG, bamboo salt and A, B and Lactobacillus plantarum (L) mixed starters (MG-ABL). MG-AB and MG-ABL significantly increased body weight and colon length compared to the control (p<0.05). MG-ABL showed significantly decreased interleukin-6 (IL-6) expression in serum compared to the control and MG-AB group (p<0.05). MG-ABL also regulated mRNA and protein levels of pro-apoptotic Bcl-2-associated X protein (Bax) and anti-apoptotic B-cell lymphoma-2 (Bcl-2) in the mice colon tissue (p<0.05). Therefore, MG-ABL exhibited the increased anticolitis effects by inhibiting damage of colon tissue, probably by regulating a pro-inflammatory cytokine of IL-6 and regulated apoptosis related genes. These results indicated that gochujang changed with good ingredients and starters had colitis preventive effects and might be due to active compounds in mixed grain and bamboo salt, and produced by L during the fermentation of gochujang.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.556-565
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• 2014

In this study, we evaluated changes in physicochemical properties, total phenol and isoflavone contents, and antioxidant activity during soymilk fermentation by a potential probiotic Lactobacillus plantarum P1201. The P1201 strain showed survival rates of 58.14% and 62.22% after 4 h exposure to acid and artificial gastric acid conditions (pH 2.5), respectively. The optimal conditions for soy-yogurt fermentation by L. plantarum were determined to be as follows: temperature of $35^{\circ}C$, seed volume of 5.0%, and sucrose content of 10.0%. The total phenol and isoflavone contents and antioxidant activity were higher in soy-powder milk (SPM) yogurt than soymilk yogurt. In particular, the highest levels of isoflavone-aglycones, such as daidzein, glycitein, and genistein (91.50, 12.34, and $61.39{\mu}g/g$, respectively), were observed after 48 h of SPM fermentation. Thus, these results suggest that the soy-yogurt extract could be used as a potential source of natural antioxidants in food.

• The Korean Journal of Food And Nutrition
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• v.17 no.4
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• pp.374-381
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• 2004

This study was performed to characterize the mechanism of the acceleration of lactic acid fermentation in milk incubated with potato flour irradiated by ${\gamma}$-ray and two types of lactobacillus, Lactobacillus bulgaricus and Streptococcus thermophillus, and to examine its effect on the quality of yogurt by assessing the acidity of lactic acid, viscosity, free amino acid, and sensory. In lactic acid fermented in the presence of 0.5% (w/w) potato flour, its acidity was higher, its pH was lower, and its viscosity was increased than lactic acid fermented in the absence of potato flour. In the sample fermented with the mixture of S. thermophillus and L. bulgaricus, the acid production rate was highest. In the samples fermented with a single type of bacteria, the acid production rate of S. thermophillus was higher than that the L. bulgaricus. Fermented a single type of bacteria with potato flour, the lysine utilization rate of L. bulgaricus and S. thermophillus was high. L. bulgaricus produced a large quantity of glutamic acid whereas S. thermophillus consumed glutamic acid. In sensory evaluation of yogurt fermented with potato flour, the preference of texture was improved while its color, taste, flavor, and overall preference were decreased. The data suggest that L. bulgaricus stimulates the growth of S. thermophillus by providing free glutamic acid that is required by S. thermophillus and thus the addition of potato flour shortens the fermentation period of yogurt.

• Journal of Microbiology and Biotechnology
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• v.8 no.5
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• pp.547-551
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• 1998

Sixty isolates of lactic acid bacteria found in kimchi, a traditional Korean dish of fermented vegetables, were tested for nisin sensitivity. Of the sixty isolates, all belonging to the genera Leuconostoc, Lactobacillus, and Pediococcus, fifty isolates were sensitive to nisin at a concentration of 100 IU/$m\ell$, and four isolates appeared to be resistant to nisin. This demonstrated that the nisin sensitivity of lactic acid bacteria found in kimchi varied considerably among isolates. In MRS broth containing nisin at concentrations of 100 to 300 IV/$m\ell$, the growth of sensitive isolates of Leuconostoc mesenteroides and Lactobacillus plantarum was inhibited for two to three days at 2$0^{\circ}C$. When nisin was added to kimchi preparations at a concentration of 100 IU/$m\ell$, the growth of lactic acid bacteria was delayed and reached a maximum two days later than that in kimchi without nisin. These results suggest the possible use of nisin in kimchi preparation, at recommended levels, to control the lactic acid fermentation. Scanning electron micrographs of a sensitive isolate L. plantarum revealed the formation of pores on cell surfaces followed by rapid cell wall destruction 1 h after the addition of nisin.