• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1517-1526
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• 2016

Lactic acid bacteria (LAB) isolated from fermented foods have potential as a treatment for immune-related disorders and the use of LAB has been increasing worldwide. In this study, the differential cytokine regulatory effect was examined with three isolates of lactobacilli strains; namely, Lactobacillus plantarum K55-5 isolated from dairy product, and L. sakei K101 and L. plantarum K8 previously isolated from kimchi (a Korean traditional fermented vegetable). Production of cytokines such as IL-10, IL-12, IFN-γ, and TNF-α was significantly increased in L. sakei K101- and L. plantarum K55-5-treated splenocytes as compared with controls. The oral administration of L. sakei K101 and L. plantarum K55-5 increased cytokine production in the immunosuppressed mouse splenocytes and blood. NK cell cytotoxic activity was also increased in L. sakei K101- and L. plantarum K55-5-fed mice. On the other hand, L. plantarum K8 did not affect cytokine induction in all the experiments performed in this study. The cytokine-inducing effect of L. plantarum K55-5 was significantly increased by lysates of heat-killed bacteria as compared with live, heat-killed, or supernatant of cell lysates. TNF-α production by lipoteichoic acids (LTAs) isolated from the three isolates of lactobacilli was compared, and it was found that K55-5 LTA had a highest cytokine-inducing ability, which was mediated by TLR2-mediated NF-κB and ERK activation. Taken together, our study suggests that L. plantarum K55-5 and L. sakei K101 can be used for the treatment of immunosuppressed disorders.

• Journal of Microbiology and Biotechnology
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• 제28권4호
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• pp.534-541
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• 2018

Kimchi (a traditional Korean fermented vegetable) was prepared with a starter, Lactobacillus zymae GU240 producing ${\gamma}$-aminobutyric acid (GABA), and one precursor of GABA (glutamic acid, glutamic acid monosodium salt (MSG), or kelp extract). L. zymae GU240, an isolate from kimchi, can grow at 7% NaCl and low temperature. Five different kimchi samples were fermented for 20 weeks at $-1^{\circ}C$. Kimchi with starter alone could not produce GABA. The GABA content was highest in kimchi with co-inoculation of the starter and MSG (1% (w/w)). Kimchi co-inoculated with the starter and kelp extract powder (3% (w/w)) had the second highest GABA content. Addition of glutamic acid powder (1% (w/w)) caused a reduction in the pH level of kimchi and growth inhibition of lactic acid bacteria and yeasts. Kimchi samples with MSG or kelp extract showed improvement of sensory evaluation scores. The results demonstrate the possibility to produce kimchi with improved functionality and taste by using L. zymae GU240 as a starter along with a suitable precursor such as MSG or kelp extract.

• 한국식품영양과학회지
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• 제29권6호
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• pp.1009-1015
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• 2000

본 연구에서는 적갓김치의 발효과정에 따른 발효특성과 항산화성을 규명하기 위해 갓김치와 가열 쇠고기를 이용한 model system을 만들어 쇠고기 지방질에 대한 항산화성을 살펴보았고 용매별로 추출한 김치성분의 항산화성을 살펴보았다. 적 갓김치는 15$^{\circ}C$에서 발효가 진행되면서 6일째 김치의 pH가 4.5에 도달하였다. 발효진행에 따라서 산도는 증가하였고 환원당은 서서히 감소하였으며 이때 젖산균수 역시 최대치에 도달하였다. 또한 a-scorbic acid 함량은 발효가 진행되면서 감소하였다가 발효 6일째에 다시 다소 증가하였다. 총 페놀함량은 생 시료에서보다는 갓김치에서 높게 나타났으며 발효가 진행됨에 따라 총 페놀함량은 증가하였다. 적 갓김치를 가열쇠고기와의 model system을 조제하여 TBA가를 통해 항산화성을 살펴본 결과 첨가한 김치의 양이 많을수록 항산화성이 높게 나타났으며 생시료일 때보다는 김치의 항산화성이 우수하였으며 발효가 진행된 숙성상태일 때 더 항산화성이 우수하였다. 동결건조시킨 적 갓김치를 물, 메탄올, 핵산 세가지 용매로 추출하여 항산화성을 살펴보았을 때 메탄을 추출물의 항산화성이 가장 높게 나타났다. 또한 담금직후보다는 숙성된 상태의 갓김치가 항산화성이 높았다.

• Nutrition Research and Practice
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• 제8권6호
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• pp.638-643
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• 2014

BACKGROUND/OBJECTIVES: Kimchi is a traditional Korean fermented vegetable containing several ingredients. We investigated the protective activity of methanol extract of kimchi under different fermentation stages against oxidative damage. MATERIALS/METHODS: Fresh kimchi (Fresh), optimally ripened kimchi (OptR), and over ripened kimchi (OvR) were fermented until the pH reached pH 5.6, pH 4.3, and pH 3.8, respectively. The radical scavenging activity and protective activity from oxidative stress of kimchi during fermentation were investigated under in vitro and cellular systems using LLC-$PK_1$ cells. RESULTS: Kimchi exhibited strong radical scavenging activities against 1,1-diphenyl-2-picrylhydrazyl, nitric oxide, superoxide anion, and hydroxyl radical. In addition, the free radical generators led to loss of cell viability and elevated lipid peroxidation, while treatment with kimchi resulted in significantly increased cell viability and decreased lipid peroxidation. Furthermore, the protective effect against oxidative stress was related to regulation of cyclooxygenase-2, inducible nitric oxide synthase, nuclear factor-${\kappa}B$ p65, and $I{\kappa}B$ expression. In particular, OvR showed the strongest protective effect from cellular oxidative stress among other kimchi. CONCLUSION: The current study indicated that kimchi, particularly OptR and OvR, played a protective role against free radical-induced oxidative stress. These findings suggest that kimchi is a promising functional food with an antioxidative effect and fermentation of kimchi led to elevation of antioxidative activity.

• 동아시아식생활학회지
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• 제19권6호
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• pp.950-957
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• 2009

Mustard Leaf Kimchi (MLK) is a traditional fermented Korean vegetable food. This study was conducted to investigate the effects of part vacuum treatment on MLK packed in a glass bottle during fermentation. There have been a few previous studies that examined the chemical and microbial changes during MLK fermentation. However, the major object of this study was to investigate the antioxidative activities of vacuum treated MLK. In this study, the antioxidative activity of vacuum treated mustard leaf Kimchi (VM) and control mustard leaf Kimchi (CM) were examined. VM and CM were fermented at $5^{\circ}C$ for 8 weeks. A model system was designed to evaluate the antioxidative activity of crude chlorophylls and carotenoids (CCC) extracts from Mustard leaf Kimchi. The oxidative reaction of the linoleic acid mixture system at $30^{\circ}C$ in the dark was quantified determining the peroxide value and conjugated dienoic acid content. The effect of the CCC extracts on lipid peroxidation in a rat liver homogenate was examined. Formation of lipid peroxides was estimated by the TBA value, and the CCC extracts were found to inhibit the TBA value. Chlorophyll a and b, and carotenoids, Which are the major components in the CCC extracts of Kimchi were isolated on a DEAE-sepharose CL-6B and Sepharose CL-6B column and TLC. The effects of chlorophyll a and b, caroteins on linoleic acid autoxidation were measured by determining the peroxide value. In addition, their effects on free radical scavenging were investigated by DPPH. In this assay, chlorophyll a showed the greatest antioxidative activity followed by chlorophyll b, and carotenoids. MLK contains a sufficient content of chlorophyll a and b, and carotenoid which have strong antioxidative activities.

• Journal of Microbiology and Biotechnology
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• 제26권6호
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• pp.1057-1062
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• 2016

Kimchi is a traditional Korean fermented vegetable food, the production of which involves brining of Korean cabbage, blending with various other ingredients (red pepper powder, garlic, ginger, salt-pickled seafood, etc.), and fermentation. Recently, kimchi has also become popular in the Western world because of its unique taste and beneficial properties such as antioxidant and antimutagenic activities, which are derived from the various raw materials and secondary metabolites of the fermentative microorganisms used during production. Despite these useful activities, analysis of the microbial community present in kimchi has received relatively little attention. The objective of this study was to evaluate the bacterial community structure from the raw materials, additives, and final kimchi product using the culture-independent method. Specifically, polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) was used to analyze the 16S rRNA partial sequences of the microflora. One primer set for bacteria, 341F^GC-518R, reliably produced amplicons from kimchi and its raw materials, and these bands were clearly separated on a 35-65% denaturing gradient gel. Overall, 117 16S rRNA fragments were identified by PCR-DGGE analysis. Pediococcus pentosaceus, Leuconostoc citreum, Leuconostoc gelidum, and Leuconostoc mesenteroides were the dominant bacteria in kimchi. The other strains identified were Tetragenococcus, Pseudomonas, Weissella, and uncultured bacterium. Comprehensive analysis of these microorganisms could provide a more detailed understanding of the biologically active components of kimchi and help improve its quality. PCR-DGGE analysis can be successfully applied to a fermented food to detect unculturable or other species.

• Journal of Microbiology and Biotechnology
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• 제33권8호
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• pp.1066-1075
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• 2023

Kimchi is a traditional Korean fermented vegetable that is stored and fermented at low temperatures. However, kimchi lactic acid bacteria (LAB) are typically isolated under mesophilic conditions, which may be inappropriate for isolating the diverse LAB. Therefore, this study investigated the suitable conditions for isolating various LAB from kimchi. Here, LAB were isolated from four kimchi samples using MRS, PES, and LBS media and varying isolation temperatures (30, 20, 10, and 5℃). Then, MRS was selected as the suitable medium for LAB isolation. A comparison of culture-dependent and culture-independent approaches indicated that 5℃ was not a suitable isolation temperature. Thus, the number and diversity of LAB were determined at 30, 20, and 10℃ using 12 additional kimchi samples to elucidate the effect of isolation temperature. With the exception of two samples, most samples did not substantially differ in LAB number. However, Leuconostoc gelidum, Leuconostoc gasicomitatum, Leuconostoc inhae, Dellaglioa algida, Companilactobacillus kimchiensis, Leuconostoc miyukkimchii, Leuconostoc holzapfelii, and Leuconostoc carnosum were isolated only at 10 and 20℃. The growth curves of these isolates, except Leu. holzapfelii and Leu. carnosum, showed poor growth at 30℃. This confirmed their psychrotrophic characteristics. In Weissella koreensis, which was isolated at all isolation temperatures, there was a difference in the fatty acid composition of membranes between strains that could grow well at 30℃ and those that could not. These findings can contribute to the isolation of more diverse psychrotrophic strains that were not well isolated under mesophilic temperatures.

• Asian-Australasian Journal of Animal Sciences
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• 제17권10호
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• pp.1411-1416
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• 2004

The objective of this work was to isolate a microorganism, able to produce high lactate dehydrogenase (LDH) activity, for use as a microbial feed additive. The LDH is an important enzyme for lactate conversion in the rumen, thereby possibly overcoming lactic acidosis owing to sudden increases of cereal in the diets of ruminants. In the present study, various bacterial strains were screened from a variety of environments. Among the isolated microorganisms, strain FFy 111-1 isolated from a Korean traditional fermented vegetable food called Kimchi showed the highest enzyme activity, along with retaining strong enzyme activity even in rumen fluid in vitro. Based on morphological and biochemical characteristics as well as compositions of cellular fatty acids plus API analyses, this strain was identified as Lactobacillus sp. The optimum temperature and pH for growth were found to be 30$^{\circ}C$ and pH 6.5, respectively. A maximum cell growth of 2.2 at $A_{650}$ together with LDH activity of 2.08 U per mL was achieved after 24 h of incubation. Initial characterization of FFy 111-1 suggested that it could be a potential candidate for use as a direct-fed microbial in the ruminant animals.

• Journal of Microbiology and Biotechnology
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• 제25권5호
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• pp.559-568
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• 2015

Kimchi is a traditional Korean vegetable product that is naturally fermented by various microorganisms present in the raw materials. Among these microorganisms, lactic acid bacteria dominate the fermentation process. Natural fermentation with unsterilized raw materials leads to the growth of various lactic acid bacteria, resulting in variations in the taste and quality of kimchi, which may make it difficult to produce industrial-scale kimchi with consistent quality. The use of starter cultures has been considered as an alternative for the industrial production of standardized kimchi, and recent trends suggest that the demand for starter cultures is on the rise. However, several factors should be carefully considered for the successful application of starter cultures for kimchi fermentation. In this review, we summarize recent studies on kimchi starter cultures, describe practical problems in the application of industrial-scale kimchi production, and discuss the directions for further studies.

• 한국미생물·생명공학회지
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• 제39권2호
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• pp.175-181
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• 2011

Kimchi is a group of traditional fermented vegetable foods in Korea and known to be the product of a natural mixed-fermentation process carried out principally by lactic acid bacteria (LAB). According to microbial results based on conventional identification, Leuconostoc mesenteroides and Lactobacillus plantarum were considered to be responsible for the good taste and over-ripening of kimchi, respectively. However, with the application of phylogenetic identification, based on 16S ribosomal RNA gene similarities, a variety of Leuconostoc and Lactobacillus species not detected in the previous studies have been isolated, together with a species in the genus Weissella. Additionally, Lactobacillus sakei has been accepted as the most populous LAB in over-ripened kimchi. In this study, Leuconostoc and Weissella species inhibiting the growth of Lb. sakei were isolated from kimchi for future applications to do with kimchi fermentation. From 25 kimchi samples, 378 strains in the genera Leuconostoc and Weissella were isolated and 68 strains identified as Lc. mesenteroides, Lc. citreum, Lc. lactis, W. cibaria, W. confusa, and W. paramesenteroides exhibited growth inhibition against Lb. sakei. Most of the strains also had antagonistic activities against Lb. brevis, Lb. curvatus, Lb. paraplantarum, Lb. pentosus, and Lb. plantarum. Their antagonistic activities against Lb. sakei were more remarkable at lower temperatures of incubation.