• Journal of Microbiology and Biotechnology
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• 제18권2호
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• pp.308-313
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• 2008

Ixeris dentata (ID, family Asteraceae), called Seumbakuy in Korea, was fermented with lactic acid bacteria (LAB) and their antiallergic activities were investigated. Fermentation of ID with Bifidobacterium breve or Lactobacillus acidophilus increased its inhibition of degranulation in RBL-2H3 cells induced by the IgE-antigen complex. Oral administration of these extracts to mice inhibited the passive cutaneous anaphylaxis (PCA) reaction induced by the IgE-antigen complex and scratching behaviors induced by compound 48/80. The fermented ID more potently inhibited the PCA reaction and scratching behaviors than the non-fermented one. These extracts also inhibited mRNA expression of TNF-${\alpha}$ and IL-4, as well as NF-${\kappa}B$ activation in RBL-2H3 cells induced by the IgE-antigen complex. These findings suggest that LAB fermentation improves ID-mediated inhibition of IgE-induced allergic diseases such as rhinitis and asthma, and that ID works by inhibiting degranulation and NF-${\kappa}B$ activation in mast cells and basophils.

• Archives of Pharmacal Research
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• 제29권9호
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• pp.735-740
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• 2006

Lactic acid bacteria (LAB) quickly attenuate or are killed during the freeze-drying process and storage. The effect of some natural polysaccharides, which are known as potent antitumor and immunomodulating substances, on the viability of the LAB, Lactobacillus acidophilus and Bifidobacterium breve, on freeze-drying and storage were investigated. Among the polysaccharides tested, red ginseng polysaccharide (RGP) and chitosan significantly inhibited the cell death of the LAB during freeze-drying, and fucoidan and RGP most potently protected the cell death of the LAB during storage. The stabilities of the LAB on the addition of RGP and fucoidan were comparable to that of skimmed milk. However, white ginseng polysaccharide (WGP) did not promote storage stability. When 5% skimmed milk/5% RGP treated LAB were freeze-dried and stored, their viabilities were found to be significantly higher those treated with 5% or 10% RGP. The stabilizing effect of 5% RGP/5% skimmed milk during LAB freeze-drying and storage stability was comparable to that of treatment with 10% skimmed milk. Based on these findings, we believe that RGP beneficially improves the stability of LAB during the freeze-dry process and storage.

• Preventive Nutrition and Food Science
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• 제17권3호
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• pp.217-222
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• 2012

This study was carried out to investigate the isolation and characterization of lactic acid bacteria (LAB) from naturally fermented sauce-type kimchi. Sauce-type kimchi was prepared with fresh, chopped ingredients (Korean cabbage, radish, garlic, ginger, green onion, and red pepper). The two isolated bacteria from sauce-type kimchi were identified as Pediococcus pentosaceus and Lactobacillus brevis by 16S rDNA sequencing and tentatively named Pediococcus sp. IJ-K1 and Lactobacillus sp. IJ-K2, respectively. Pediococcus sp. IJ-K1 was isolated from the early and middle fermentation stages of sauce-type kimchi whereas Lactobacillus sp. IJ-K2 was isolated from the late fermentation stage. The resistance of Pediococcus sp. IJ-K1 and Lactobacillus sp. IJ-K2 to artificial gastric and bile acids led to bacterial survival rates that were 100% and 84.21%, respectively.

• 한국식품영양학회지
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• 제15권3호
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• pp.215-219
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• 2002

Sourdough 빵을 생산하기 위해 사용되는 유산균중 Lb. brevis는 높은 산 생성율과 단백질 분해 활성과 sourdough 발효중 발생되는 휘발성 화합물의 합성에 뚜렷하게 기여를 하여 많이 사용되고 있다. 따라서 본 실험은 김치에서 분리한 유산균을 sourdough starter로 사용하기 위한 첫 번째 단계로서 Lactobacillu brevis UC-22의 배양 특성 및 최적 성장조건을 조사하였다. 온도에 따른 증식은 35$^{\circ}C$에서 배양한 것이 PH의 저하 및 증식이 가장 양호하였으며 이에 병행하여 산 생성량도 균주의 대수 증식기에서 활발하게 분비되는 것을 알 수 있었다. 배지내의 pH에 따른 균의 생장은 pH 5.5와 pH6.5일 때 증식이 우수하게 나타났다. Lb. brevis의 특징적인 탄소원 이용은 glucose보다는 오히려 maltose를 더 선호하는 경향이 있다고 하였으나 본 실험에 사용된 Lactobacillus brevis UC-22는 maltose와 glucose의 첨가에 따른 성장 정도는 큰 차이점을 보이지 않았다.

• 한국식품조리과학회지
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• 제19권4호
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• pp.521-528
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• 2003

This research was conducted to find the effects of the addition of kugija to the quality and conservativeness of Nabak kimchi. Kugija extract was prepared by boiling kugija fruits, at different ratios (1, 3, 5 and 7%; w/v) in water for 30 minutes. The changes in the sensory and microbiological properties of the Nabak kimchi were measured for 25 days, following the preparation at a uniform temperature of 10$^{\circ}C$, and compared to a control (distilled water without kugija). For the properties of acceptability, the Nabak kimchi treated with 3% kugija was evaluated as being best during the whole fermentation. The number of total cell counts and number of lactic acid microorganisms gradually increased to a maximum, and then decreased. It was the maximum for controlling and 1 % treatment on day 2, forand 3, 5 and 7% treatment on day 7. (Eds note: the highlighted sentence needs c1arification\ulcorner)This experimental study revealed the effect of kugija extract in enhancing the eating qualities on Nabak kimchi and retarding the fermentation over the initial seven days. The optimum levels of kugija extract on Nabak kimchi obtained through experiments was between 1 and 3% of the water content. Although 3% gave a better color, the fermentation-retarding effect and savory taste. The application of kugija extract could be domestically applied to improve the eating quality and the preservation of traditionally prepared Nabak kimchi.

• International Journal of Oral Biology
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• 제44권2호
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• pp.31-36
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• 2019

Streptococcus mutans is one of the important bacteria that forms dental biofilm and cause dental caries. Virulence genes in S. mutans can be classified into the genes involved in bacterial adhesion, extracellular polysaccharide formation, biofilm formation, sugar uptake and metabolism, acid tolerance, and regulation. The genes involved in bacterial adhesion are gbps (gbpA, gbpB, and gbpC) and spaP. The gbp genes encode glucan-binding protein (GBP) A, GBP B, and GBP C. The spaP gene encodes cell surface antigen, SpaP. The genes involved in extracellular polysaccharide formation are gtfs (gtfB, gtfC, and gtfD) and ftf, which encode glycosyltransferase (GTF) B, GTF C, and GTF D and fructosyltransferase, respectively. The genes involved in biofilm formation are smu630, relA, and comDE. The smu630 gene is important for biofilm formation. The relA and comDE genes contribute to quorumsensing and biofilm formation. The genes involved in sugar uptake and metabolism are eno, ldh, and relA. The eno gene encodes bacterial enolase, which catalyzes the formation of phosphoenolpyruvate. The ldh gene encodes lactic acid dehydrogenase. The relA gene contributes to the regulation of the glucose phosphotransferase system. The genes related to acid tolerance are atpD, aguD, brpA, and relA. The atpD gene encodes $F_1F_0$-ATPase, a proton pump that discharges $H^+$ from within the bacterium to the outside. The aguD gene encodes agmatine deiminase system and produces alkali to overcome acid stress. The genes involved in regulation are vicR, brpA, and relA.

• Journal of Microbiology and Biotechnology
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• 제34권6호
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• pp.1314-1321
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• 2024

Branched-chain hydroxy acids (BCHAs), produced by lactic acid bacteria, have recently been suggested as bioactive compounds contributing to the systemic metabolism and modulation of the gut microbiome. However, the relationship between BCHAs and gut microbiome remains unclear. In this study, we investigated the effects of BCHAs on the growth of seven different families in the gut microbiota. Based on in vitro screening, both 2-hydroxyisovaleric acid (HIVA) and 2-hydroxyisocaproic acid (HICA) stimulated the growth of Lactobacillaceae and Bifidobacteriaceae, with HIVA showing a significant growth promotion. Additionally, we observed not only the growth promotion of probiotic Lactobacillaceae strains but also growth inhibition of pathogenic B. fragilis in a dose-dependent manner. The production of HIVA and HICA varied depending on the family of the gut microbiota and was relatively high in case of Lactobacillaceae and Lachnosporaceae. Furthermore, HIVA and HICA production by each strain positively correlated with their growth variation. These results demonstrated gut microbiota-derived BCHAs as active metabolites that have bacterial growth modulatory effects. We suggest that BCHAs can be utilized as active metabolites, potentially contributing to the treatment of diseases associated with gut dysbiosis.

• 한국축산식품학회지
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• 제44권2호
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• pp.372-389
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• 2024

This study investigated the efficacy of ultraviolet-C (UV-C) irradiation in enhancing the quality of raw bovine milk by targeting microbial populations and lipid peroxidation, both of which are key factors in milk spoilage. We categorized the raw milk samples into three groups based on initial bacterial load: low (<3 Log 10 CFU/mL), medium (3-4 Log 10 CFU/mL), and high (>4 Log 10 CFU/mL). Using a 144 W thin-film UV-C reactor, we treated the milk with a flow rate of 3 L/min. We measured the bacterial count including standard plate count, coliform count, coagulase-negative staphylococci count, and lactic acid bacteria count and lipid peroxidation (via thiobarbituric acid reactive substances assay) pre- and post-treatment. Our results show that UV-C treatment significantly reduced bacterial counts, with the most notable reductions observed in high and medium initial load samples (>4 and 3-4 Log 10 CFU/mL, respectively). The treatment was particularly effective against coliforms, showing higher reduction efficiency compared to coagulase-negative staphylococci and lactic acid bacteria. Notably, lipid peroxidation in UV-C treated milk was significantly lower than in pasteurized or untreated milk, even after 72 hours. These findings demonstrate the potential of UV-C irradiation as a pre-treatment method for raw milk, offering substantial reduction in microbial content and prevention of lipid peroxidation, thereby enhancing milk quality.

• 한국식품위생안전성학회지
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• 제16권1호
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• pp.16-20
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• 2001

본 연구는 하계 (’98년 6월-8월)닭고기 (평균 500g 중량의 삼계)다리를 초산, 유산 및 구연산 용액으로 침지한 다음 미생물 및 관능평가를 실시하였다. 닭고기 다리는 각 1%농도의 유기산 용액으로 10분 동안 침지하였다. 17분동안 1% 초산으로 침지한 닭고기 다리는 유산 및 구연산 처리구 보다 4$^{\circ}C$ 저장 16일 동안 유의적 (P<0.05)으로 낮은 호기성 세균 및 그람음성 세균수를 나타내었다. 초산의 항균력은 유산과 구연산 용액의 처리구 보다 높게 유지되었다. 초산으로 처리한 닭고기 다리의 미생물학적 저장 안정성은 대조구 보다 8일 증가하였다. 유기 산으로 처리한 닭고기 다리의 냄새 및 외관에 대한 관능평가의 결과는 4$^{\circ}C$ 저장 12일 동안 대조구와 유사하거나 낮게 유지되었다.

• Journal of Dairy Science and Biotechnology
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• 제22권2호
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• pp.99-106
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• 2004

포자형성 유산균주에 대하여 종양세포에 대한 증식 억제 활성과 항산화 활성 및 세포내 glutathione 함유율을 측정하였다. 종양세포에 대한 억제활성은 균주에 따라 큰 차이를 나타내었고 Bacillus coagulans KTCC 3675는 높은 수준의 특이한 수준의 억제 활성을 나타내었고 human lymphoma cell NCLH-1299에 대한 억제 활성은 미약한 수준인 것으로 확인되었다. TBA 방법에 의한 linoleic acid에 대한 항산화 활성은 5~25% 정도의 항산화 활성을 보였고 특별히 높은 수준의 항산화 활성을 보인균주는 Bacillus coagulans KTCC 625, Bacillus coagulans KTCC 1015 및 Lactobacillus sporogens CU 815인 것으로 확인되었다. 포자형성 유산균체 추출액의 linoleic acid과산화 억제 활성과 세포내 glutathione함유율과의 상관계수는 0.78로서 고도의 유의성이 인정되는 상관계수를 나타내었다.