• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.204-210
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• 2015

Makgeolli is made from rice or flour, yeast, and nuruk, a fermentation starter. The flavor of makgeolli is affected by sugars, amino acids, organic acids and volatile flavor compounds produced by various microorganisms. In this study, lactic acid bacteria (LAB) were isolated from unsterilized makgeolli samples collected from several provinces in Korea, and then later identified. Under anaerobic conditions, LAB density ranged from $5.0{\times}10^6$ to $1.5{\times}10^8CFU/mL$; yeast density ranged from $2.5{\times}10^7$ to $1.5{\times}10^8CFU/mL$. Of the LAB isolated from makgeolli, 1,126 were analyzed using restriction fragment length polymorphism (PCR-RFLP) analysis of 16S rRNA, which allowed for classification into five groups. Of the 1,126 LABs tested, 130 produced ${\gamma}$-aminobutyric acid (GABA).

• Journal of Life Science
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• v.33 no.3
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• pp.260-267
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• 2023

Helicobacter pylori infects the mucosa, induces chronic inflammation and ulcers, and is known as a biological carcinogen. Antibiotics are used as therapeutic agents for H. pylori, but there are problems such as resistance. Thus, research is being conducted on the use of lactic acid bacteria (LAB) as an alternative therapeutic agent. There have been many studies on LAB related to kimchi. However, studies related to Gajami Sikhae, a traditional fermented seafood in Korea, are insufficient. In this study, we investigated the inhibitory effect of LAB isolated from Gajami Sikhae on H. pylori and its use as a probiotic. Forty species of LAB isolated from Gajami Sikhae were identified as Lactobacillus plantarum, Lactobacillus brevis, Leuconostoc mesenteroides, and Weisella paramesenteroides, and 10 strains of 40 species were selected through liquid inhibition assay of H. pylori. The selected LAB supernatant at 1%, 5%, and 10% had a growth inhibitory effect on H. pylori 52, 51, e-53, and 309. The adjusted pH of 7.0 was used for the LAB culture supernatant, in reference to a study that the growth of H. pylori is affected by acid. All 10 strains of LAB at 5% and 10% concentration suppressed the growth of H. pylori 52, and 7 strains of LAB at 10% concentration suppressed the growth of H. pylori e-53. LAB also had the effect of suppressing the activity of urease. Finally, LAB isolated from Gajami Sikhae is expected to be useful for eradicating and preventing H. pylori.

• Korean Journal of Microbiology
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• v.53 no.3
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• pp.180-192
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• 2017

The purpose of this study is to investigate the antioxidative and antimicrobial activities of sourdough fermented with the lactic acid bacteria (LAB) isolated from sliced radish kimchi. According to 16S rRNA gene sequence analysis, the isolated lactic acid bacteria were categorized as Leuconostoc dextranicum SRK03, Lactobacillus brevis SRK15, Pediococcus halophilus SRK22, Lactobacillus acidophilus SRK30, Lactobacillus plantarum SRK38, Leuconostoc citreum SRK 42, and Lactobacillus delbrueckii SRK60 with sequence similarity of 99%. After fermentation with L. dextranicum SRK03, L. acidophilus SRK30, L. plantarum SRK38 or L. delbrueckii SRK60 and Saccharomyces cerevisiae KCTC 7246 at $30^{\circ}C$ for 24 h LAB and yeast in sourdough were present at levels of $10^9$ and $10^7CFU/g$, respectively. In particular, the titratable acidity and ethanol and exopolysaccharide contents of sourdough fermented with L. dextranicum SRK03 were also significantly (P < 0.05) higher than those of sourdough fermented with L. acidophilus SRK30, L. plantarum SRK38, or L. delbrueckii SRK60. The sourdough fermented with L. dextranicum SRK03 and L. acidophilus SRK30 showed not only good DPPH radical-scavenging capacity but anti-lipid peroxidation activity. In addition, the viable counts of Bacillus cereus ATCC 11778 and Staphylococcus aureus ATCC 6538 in sourdough during storage for 5 days at $25^{\circ}C$ were significantly (P < 0.05) lower than those of pathogenic bacteria in the control group due to the organic acids and bacteriocin produced by L. acidophilus SRK30 strain.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.10a
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• pp.326-329
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• 2004

본 연구에서는 김치로부터 분리한 L. brevis, L. curvatus, L. plantarum, L. sake가 발효소시지 환경에 잘 적응하는지 그리고 어떠한 발효 대사 특성을 가지는지에 대해 조사하였다. 조사한 젖산균들 중에서 L. plantarum은 가장 좋은 성장도와 함께 좋은 pH 저하 능력을 보여주었을 뿐 아니라 homo-fermentative 특성을 보여주어 starter culture로 사용될 가능성을 보여 주었다. 또한 L. plantarum은 첨가된 nitrate나 nitrite를 분해하는 능력까지 보여 조사한 젖산균들 중에서 starter culture로서 가장 적절할 것으로 여겨지나, 이들도 첨가된 nitrate나 nitrite에 의해 그 성장도가 저해되는 현상을 볼 수 있었다.

• Microbiology and Biotechnology Letters
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• v.32 no.3
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• pp.249-255
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• 2004

Chinese cabbage ('Baechu') Kimchi was fermented at the three different temperatures right after it was prepared. Samples were taken everyday for measuring bacterial populations, pH, and titratable acidity through the whole periods of fermentation up to 50 days. pH values and developed acidity were significantly affected by the fermenting temperatures of 4, 10, and $20^{\circ}C$, suggesting that different bacterial flora has been established by the temperatures exposed. The modified MRS agar containing vancomycin (300 $\mu$g/mL) was used for isolating the vancomycin-resistant LAB strains and 127 isolates were finally obtained. Of the LAB isolates, 13 isolates were subjected to the identification experiments based on the biochemical characteristics and the molecular-typing approach, an ITS-PCR, whether they belong to the genus Leuconostoc or not. The data obtained from API 50 CHL kit resulted that six isolates were identified as the members of Leuconostoc and six as Lactobacillus brevis strains except for a single isolate YKI 30-0401, which was not able to be identified because its biochemical traits were not matched to the database of API 50 CHL kit. It was noted that some isolates were distinct in a couple of some biochemical characteristics compared with those of the reference Leuconostoc species. To overcome the limitations experienced in the commercial identification products above, an ITS-PCR experiment was also conducted for the isolates, resulting that eight isolates belong to Leu. mesenteroides ssp. mesenteroides or dextranicum with a single band of 564 bp, and four to L. brevis strains. The ITS-PCR profiles clearly differentiated the closely-related LAB isolates for which same results were obtained by the biochemical method. This molecular approach, however, failed to produce the amplicons for the YKI 20-1003, leaving the strain unidentified. Judging from the identification data obtained in the Kimchi fermented at $4^{\circ}C$ or $10^{\circ}C$, Leuconostoc spp. including Leu. mesenteroides/dextranicum were likely predominant species in the earlier stage and L. brevis occurred at the high level through the whole period. By contrast, L. brevis, as one of the major flora, possibly lead the fermentation from the beginning in the Kimchi fermented at $20^{\circ}C$.}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1872-1877
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• 2013

Lactic acid bacteria were selected on the basis of lactic acid producing ability from kimchi, a traditional Korean fermented food. Among the initial screening of over 150 strains selected from the sample, 27 strains were selected as lactic acid producing bacteria, and 4 strains were finally selected based on their ability to produce relatively high levels of lactic acid. The four strains were identified as Lactobacillus (L.) plantarum Gk04, Pediococcus pentosaceus Gk07, L. brevis Gk35 and L. curvatus Gk36 by the conventional morphological, cultural, physiological and biochemical characteristics, as well as by 16S rRNA sequence analysis. Among the identified lactic acid bacteria, L. curvatus Gk36 was used for soymilk fermentation. The viable cell counts and acidity values measured for the L. curvatus Gk36 were comparable to the commmercial L. acidopillus. Thus, the L. curvatus Gk36 is a potential probiotic strain to prepare fermented soy products, such as kephir, yogurt, tempeh and soy sauce.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.77-83
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• 2013

In this study, we observed optimal conditions and suitable bacteria for the fermentation of steam-dried ginseng berry extracts (SGB) and determined antioxidant effects of the fermented extracts. Five bacteria (Lactobacillus fermentarum, L. plantarum, L. brevis, L. casei, Bacillus subtillis) were examined on their growth activities and viabilities in various culture temperatures ($25-35^{\circ}C$) and concentrations (25-100%). L. plantarum was considered to be the most suitable bacteria for the fermentation in both growth activity and viability. Moreover, the extracts fermented with L. plantarum showed more potent antioxidant efficacy in both 1,1-diphenyl-2-picrylhydrazyl radical and hydroxyl radical scavenging assay. High performance liquid chromatography analysis revealed that fermentation with L. plantarum changed the contents and components of ginsenosides. In conclusion, these data suggest that L. plantarum efficiently ferment SGB and the fermented extracts may have therapeutical values against oxidative stress and be a good candidate in adjuvant therapy where ginsenoside would be the main composition.

• Microbiology and Biotechnology Letters
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• v.31 no.3
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• pp.292-296
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• 2003

The antibacterial effect against cariogenic bacteria was evaluated in combination of 5-FC and intracellular cytosine deaminase from Chromobacterium violaceum YK 391. While S. mutans, L. parabuchneri and A. naeslundii showed antibacterial effect against 10 mM of 5-FU, S. intermedius, S. mitis, S. agalactiae, L. lactis, A. israelii, A. viscosus don't caused antibacterial effect. The addition of the cytosine deaminase and 10 mM of 5-FC to S. mutans, S. sanguis, L. brevis, L. parabuchneri, L. oris and A. naeslundii caused weakly antibacterial effect. S. sanguis caused weakly antibacterial effect against 10 mM of 5-FC. These results suggested that combination of the cytosine deaminase and 5-FC was showed the possibility to precautionary measures of dental caries.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.438-445
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• 2014

We examined biogenic amine (BA) production as well as the diversity of bacterial flora in 11 types of commercial makgeolli stored at 4 and $20^{\circ}C$. Moreover, we studied the BA-producing activity of three L. plantarum strains isolated from makgeolli. At $20^{\circ}C$, the BA content was highly increased and the denatured DNA bands were more variable in non-sterilized makgeolli compared to sterilized makgeolli. The major BAs produced in commercial makgeolli were histamine and putrescine. Histamine, tyramine, putrescine, and cadaverine were produced in excess by inoculation of the three L. plantarum isolates to makgeolli stored at $20^{\circ}C$ for 21 days. These results suggest that some L. plantarum strains in makgeolli can produce different types of BAs, depending on the extent of degradation of makgeolli.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.2
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• pp.112-120
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• 2006

For the conversion of food waste into a good recycling material such as animal feed without antibiotics, thirteen lactic acid bacteria, which can be used as good probiotics for animal feed, were isolated from the intestine and feces in pigs. All isolates showed strong tolerance to high salt (4% of NaCl), acid(pH4.0), and bile juice (0.8% of oxgall). The growth rate was best at $37^{\circ}C$ in all strains. Among the isolates, Lactobacillus plantarum CJY-22, L. brevis CJY-42, L. arizonensis CJY-3, and Pediococcus sp. CJY-41 showed higher and broader spectrum of antimicrobial activities against six different pathogens such as Salmonella, typhimurium. L. plantarum CJY-22 has also grown well at $25^{\circ}C$, making this strain as an appropriate candidate for the fermentation of food waste at room temperature, thus conducting the fermentation process cost-effectively.