• Journal of Dairy Science and Biotechnology
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• 제35권1호
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• pp.55-72
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• 2017

The second article of 'Effects of heat treatment on the nutritional quality of milk,' titled 'Destruction of microorganisms in milk by heat treatment' and authored by Dr. Seong Kwan Cha, who worked at the Korea Food Research Institute, covers the heat-stable microorganisms that exist in milk after pasteurization. The article focusses on the microbiological quality of raw milk and market milk following heat treatment, and is divided into four sub-topics: microbiological quality of raw milk, survey and measurement of microorganisms killed in raw milk, effect on psychrophilic and mesophilic microorganisms, and effect of heat treatment methods on thermoduric microorganisms. Bacillus spp. and Clostridium spp. are sporeforming gram-positive organisms commonly found in soil, vegetables, grains, and raw and pasteurized milk that can survive most food processing methods. Since spores cannot be inactivated by LTLT (low temperature long time) or HTST (high temperature short time) milk pasteurization methods, they are often responsible for food poisoning. However, UHT (ultra high temperature) processing completely kills the spores in raw milk by heating it to temperatures above $130^{\circ}C$ for a few seconds, and thus, the UHT method is popularly used for milk processing worldwide.

• IMMUNE NETWORK
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• 제13권5호
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• pp.205-212
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• 2013

Dectin-1, which specifically recognizes ${\beta}$-glucan of fungal cell walls, is a non-Toll-like receptor (TLR) pattern recognition receptor and a representative of C-type lectin receptors (CLRs). The importance of Dectin-1 in innate immune cells, such as dendritic cells and macrophages, has previously been well studied. However, the function of Dectin-1 in B cells is very poorly understood. To determine the role of Dectin-1 in B cell activation, we first investigated whether mouse B cells express Dectin-1 and then assessed the effect of Dectin-1 stimulation on B cell proliferation and antibody production. Mouse B cells express mRNAs encoding CLRs, including Dectin-1, and surface Dectin-1 was expressed in B cells of C57BL/6 rather than BALB/c strain. Dectin-1 agonists, heat-killed Candida albicans (HKCA) and heat-killed Saccharomyces cerevisiae (HKSC), alone induced B cell proliferation but not antibody production. Interestingly, HKSC, HKCA, and depleted zymosan (a selective Dectin-1 agonist) selectively enhanced LPS-driven IgG1 production. Taken together, these results suggest that, during fungal infection, ${\beta}$-glucan-stimulated Dectin-1 may cooperate with TLR4 to specifically enhance IgG1 production by mouse B cells.

• 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.

• 한국미생물·생명공학회지
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• 제40권4호
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• pp.310-318
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• 2012

유세포 형광분석에 의한 유산균의 면역증진 효과와 황색포도상구균에 대한 유산균의 항균활성을 확인하여 항아토피 기능성이 있는 유산균을 탐색하고 그 배양법을 검토하였다. T cell에서 CD4+/CD25+/foxp3+ 증가는 Lactobacillus plantarum, Lactococcus lactis subsp. lactis (Lc. lactis)의 순으로 면역증진효과를 보였고, 황색포도상구균에 대한 항균력은 Lc. lactis, Lb. plantarum의 순으로 나타냈다. Lc. lactis 배양액 첨가배지에 Lb. plantarum을 배양한 실험에서는 항균력의 증가가 없었으나 Lb. plantarum 배양액 첨가배지에 Lc. lactis를 배양한 실험에서 황색포도상구균의 항균활성 증대가 나타났다. 항균력을 증가시키는 유산균 첨가배지법의 최적조건은 Lb. plantarum 배양상층액 10%를 첨가하고 가열살균한 배지에서의 Lc. lactis 배양으로 나타났다. 이때 유산균의 항균역가는 Lc. lactis 순수배양 시보다 대수기 말기에 급격히 증가하여, 황색포도상구균의 증식 억제력이 1.29배 높아졌다.

• 미생물학회지
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• 제37권1호
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• pp.15-20
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• 2001

Aspergillus sp. HCLF-4가 생성하는 세균 세포벽 분해효소의 특성을 규명하였다. 본 세포벽 분해 효소는 Anabaena cylindrica 세포벽 분해능을 보였다. 이 세포벽 분해 효소는 Aspergillus sp. HCLF-4를 기질성분으로 0.05% heat killed Micrococcus luteus가 포함된 PDB 배지에 키웠을 때 생성되는 inducible enzyme으로 분자량은 약 14.3 kDa 이었다. 본 세포벽 분해효소는 pH 3.0-4.0, 온도 $30^{\circ}C$ 조건에서 최고의 활성을 보였고 $Mg^{2+}$와, $Mn^{2+}$의 2가 이온에서 분해 효소의 활성이 촉진되었다. 반면, 1가 양이온 $Na^{+}$와 $Li^{+}$, 2강 양이온 $Ca^{2+}$와 $Cu^{2+}$, 3가 양이온 $Fe^{3+}$에서는 활성이 억제되었으며 EDTA와 PMSF 또한 분해 효소의 활성을 억제 시켰다. 이 효소는 N-acetylmuramyl-L-amidase 또는 endopeptidase와 같은 활성을 보였다.

• 한국작물학회지
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• 제43권3호
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• pp.147-151
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• 1998

The conductivity test is a measure of electrolytes leakage from plant tissue. The shorter the maturation period after heading was the greater electrical conductivity (EC) of rice seed. The polymer-coated seed was not different in EC compared with non-coated seed. As soaking time of rice seed increased, EC increased gradually. The EC varied from 9.9 to 20.7$\mu$S $cm^{-1}g^{-l}$ for control plots and from 21.3 to 41.7$\mu$S $cm^{-1}g^{-l}$ for heat-killed seeds which were produced by autoclaving seeds at 121$^{\circ}C$ for 20 minutes. The germination speed (the rate of 5th day) of rice seed was 94% at control plot, 83% at low temperature and 20% at high temperature. Besides, germination percentage was 95% for the control, 92% for the low temperature treatment and 39% for the high temperature treatment. The EC was negatively correlated (r=-0.771$^{**}$) with germination percentage at low temperature. Water uptake in seeds of 30, 40, 50 days after heading (DAH) was greater than that of 20 DAH. Plant height of seedlings was 9.84 cm for the control but 4.32 cm for the high temperature treatment, and the tallest for polymer-coated seed. Dry weight of seedlings was 0.841 g for the control and 0.287 g at high temperature. Besides, the polymer-coated seed was heavier than non-coated seed. The number of roots was largest from 40 to 50 DAH and polymer-coated seed, but was decreased from 20 to 30 DAH. The length of roots was 20.52 cm at control plot and 19.89 cm polymer-coated seed but 8.68 cm for the low temperature treatment and 7.28 cm for the high temperature treatment.

• Journal of Microbiology and Biotechnology
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• 제30권9호
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• pp.1379-1386
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• 2020

Acne is a chronic skin disease that typically occurs in the teens and twenties, and its symptoms vary according to age, sex, diet, and lifestyle. The condition is characterized by hyperproliferation of keratinocytes in the epidermis, sebum overproduction, excessive growth of Propionibacterium acnes, and P. acnes-induced skin inflammation. Interleukin (IL)-1α and IL-6 are predominant in the inflammatory lesions of acne vulgaris. These cytokines induce an inflammatory reaction in the skin in the presence of pathogens or stresses. Moreover, IL-1α accelerates the production of keratin 16, which is typically expressed in wounded or aberrant skin, leading to abnormalities in architecture and hyperkeratinization. Orobol (3',4',5,7-tetrahydroxyisoflavone) is a metabolite of genistein that inhibited the P. acnes-induced increases in IL-6 and IL-1α levels in human keratinocytes (HaCaTs) more effectively compared with salicylic acid. In addition, orobol decreased the IL-1α and IL-6 mRNA levels and inhibited the phosphorylation of inhibitor of kappa-B kinase, nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha, and mitogen-activated protein kinase induced by P. acnes. Finally, the expression of Ki67 was decreased by orobol. Thus, orobol ameliorated the inflammation and hyperkeratinization induced by heat-killed P. acnes and thus has potential for use in functional foods and cosmetics.

• 미생물학회지
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• 제33권4호
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• pp.242-246
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• 1997

Synechococcus sp. cyanophage의 SDS-PAGE 수행 결과 구조단백질은 두 개의 major protein(97 kDa, 52 kDa)과 최소 일곱 개의 minor protein(70 kDa, 65 kDa, 60 kDa, 40 kDa, 35 kDa, 28 kDa, 6 kDa)으로 구성되어 있는 것으로 나타났다. Subunit들은 서로 disulfide bond로 연결되어 있지는 않지만 비공유적 결합으로 multimer를 형성하여 phage particle을 구성하고 있는 것으로 보인다. 또한 heat-killed Micrococcus luteus cell을 기질로 이용한 renaturing SDS-PAGE 방법으로 phage particle내의 세포벽 분해능을 살표본 결과 52 kDa 부근에서 세포벽 분해활성이 발견되었다. 이러한 세포벽 분해활성은 최적 pH가 9~10 사이이며 EDTA에 대한 낮은 저해를 나타내었다.

• 융합정보논문지
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• 제11권11호
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• pp.239-247
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• 2021

본 논문은 대체식품 및 화장품 원료로 사용되는 미강을 발효를 통해 기능성과 경쟁력을 증가시키는 것을 목표로 하였다. 미강 추출물과 누룩에서 분리된 Saccharomycopsis fibuligera A8로 발효된 미강 추출물을 이용해 세포독성과 항염효과를 확인하였다. 세포 독성의 경우 미강 추출물의 경우 100 ㎍/mL에서 세포독성을 보였으나 발효 미강 추출물의 경우에는 세포독성을 보이지 않았다. 한편 nitric oxide, IL-6, TNF-α, IL-1β와 같은 염증 지표를 통해 항염효과를 확인한 결과, 미강 추출물은 nitric oxide, TNF-α만 100 ㎍/mL이상의 농도에서 항염효과를 보였다. 발효 미강 추출물의 경우에는 각각 25 ㎍/mL, 25 ㎍/mL, 50 ㎍/mL, 50 ㎍/mL의 농도에서 항염효과를 보여 더 낮은 농도로 항염효과를 나타내는 것을 확인하였다. 한편 S. fibuligera A8 사균체의 세포 독성 및 항염 효과를 실험한 결과 발효 산물에서 사균체 역시 유효하게 작용하는 것을 알 수 있었다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.172-175
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• 2003

Run-Out-Table is the region between EDT and CT. Hot killed strip is cooled by air and water in ROT. In this procedure, phase transformation and shape deformation occur due to temperature drop. Because of un-ideal cooling condition, deformation of strip and non-uniform phase distribution come into existence. This phenomenon affects the strip property and lead th the existence of residual stress. And it exerts effects on the Coiling process, Coil Cooling process, and Un-coiling process. Through these process, the residual stresses of strip are more larger and unbalance of these stresses become more severe. Finite element (FE) based models for the analysises of non-steady state heat transfer and elastoplastic deformation are described in this investigation. The analysises of thermodynamics and phase transformation kinetics are suggested also. Using the ROT simulation result coiling process and coil cooling process simulations are carried out.