• 한국미생물·생명공학회지
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• 제18권1호
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• pp.26-30
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• 1990

포도에서 분리하여 동정한 Candida dattila K109와 K112 균주는 Kluyveromyces, Hansenula, Debaryomyces, Torulopsis, Brettanomyces속 효모에 대해 killer 활성을 가졌으며, 이들 균주의 최적 pH는 3.9-4.0이고, 최적 온도는 22-26$^{\circ}C$였다. Candida dattila K109와 K112 균주의 toxin은 단백질 분해효소인 pronase E와 pepsin에 의한 killer 활성이 없어졌으며, 2$0^{\circ}C$에서는 비교적 안정하였으나 $25^{\circ}C$ 이상에서는 killer 활성이 급격히 감소하였으며, pH 2.0-4.0 범위에서 비교적 안정하였고 그 이상의 pH에서는 급격히 활성이 저하되었다. 이들 균주의 killer toxin은 gel filtration에 의하여 단백질과 당을 확인하였다. Candida dattila K109와 K112 균주는 0.0105-0.3ppm cycloheximide 처리에 의하여 처리농도가 놓을 수록 killer 활성이 소멸되는 비율이 증가하였으며, 30-37$^{\circ}C$의 가온처리에 의하여 killer활성이 소멸되지 않는 등 기존의 killer 효모의 특성과 다소 다른 특성을 나타내었다.

• 지식경영연구
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• 제15권4호
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• pp.79-103
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• 2014

This research investigates whether product types moderate the relationship between e-tailer characteristics and shopping attitudes in the context of online category killer stores. To identify the antecedents of consumer attitudes for category killer stores, the product types are characterized by the two dimensions of hedonic and utilitarian. A total of 268 responses were collected from consumers who experienced online category killer stores. The results show that the quality of information contained in a website, customer review, relational benefits, and the expertise of the e-tailer are important determinants for shopping attitudes of consumers. Regarding the moderating effects of product types, hedonic value significantly moderates the relationships between shopping attitudes and relational benefits/e-tailer expertise. However, utilitarian value does not significantly moderate the relationships between shopping attitudes and any of the e-tailer characteristics. Theoretical contributions of this study are the findings of moderating effects of hedonic value on the relationships between e-tailer characteristics and shopping attitudes. In addition, this study practically implies how companies can utilize these characteristics strategically for marketing and the selection of products.

• 디지털융복합연구
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• 제12권6호
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• pp.297-310
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• 2014

본 연구는 스마트폰의 킬러앱이 가지고 있는 특성(정보특성과 네트워크 외부성)이 전환비용과 고착화를 통하여 사용자의 스마트폰 사용간의 영향 관계를 알아보고, 킬러앱과 이동통신사의 지속적인 사용간의 영향을 조사하였다. 연구 결과, 정보특성과 네트워크 외부성은 전환비용과 고착화에 긍정적인 영향을 미치는 것으로 나타났다. 전환비용은 고착화에는 긍정적인 영향을 미치지만 킬러앱의 지속적인 사용의도에는 영향을 미치지 않는 것으로 나타났다. 고착화는 킬러앱의 지속적 사용의도에 긍정적인 영향을 미치는 것으로 나타났으며, 전환비용과 킬러앱의 지속적 사용의도 사이에서 매개역할을 하는 것으로 나타났다. 마지막으로 킬러앱의 지속적 사용의도는 이동통신사의 지속적인 사용의도에 긍정적인 영향을 미치는 것으로 나타났다.

• 미생물학회지
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• 제27권4호
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• pp.415-421
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• 1989

Ten strains out of about 1,000 yeast strains isolated from byproducts of alcoholic industries, milk products, fruits, greens, food-related industries and soils of nature, revealed the killer activities. Two strains which have excellent killer activities among them were isolated and identified with Saccharomyces cerevisiae B 15-1 and Hansenula anomala Y 33 by investigation of the morphological, cultural and physiological properties. The optimal conditions on these strains for the production of killer toxin were investigated. The strain B 15-1 showed the highest killer toxin activities when it was cultured up to the log phase of 48 hr in YPD medium (pH 4.7) at $25^{\circ}C$. On the other hand, the strain Y33 revealed the highest activities when it was cultured up to the stationary phase of 60 hr in YPD medium (pH 4.0) at $20^{\circ}C$. The sensitive strain Kyokai 7 was found to be killed entirely by the killer toxin produced from the wild killer yeast B 15-1 when B 15-1 was cocultured with the same cell concentration ($10^{6}$ cells/ml) of Kyokai 7 after cultivation of 36 hr, and with large concentration ($9\times 10^{7}$ cells/ml) after 48 hr.

• 한국식품영양과학회지
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• 제36권8호
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• pp.1077-1082
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• 2007

본 연구에서는 발효식품의 저장기간을 연장하거나 이상발효를 방지하기 위해 미생물 유래의 천연 항균성 물질인 killer toxin 생산 균주인 K3, K5, K11, K12, K15를 전통누룩으로부터 분리하였다. 분리된 killer toxin 생산 균주 중 식중독의 원인균인 Salmonella Typhimurium 및 장염비브리오의 원인균인 Vibrio parahaemolyticus의 생육을 저해하며, killer toxin 활성이 가장 우수한 K15를 최종 선발하고 이를 Biolog사 동정시스템과 ITS영역의 염기서열 homology를 조사하여 동정한 결과, Pichia anomala에 99% 상동성을 나타내어 Pichia anomala K15로 명명하였다. P. anomala K15가 생산하는 killer toxin은 단백질 분해효소에 의해 불활성화 되므로 인체에서 단백질 분해효소에 의해 쉽게 분해가 가능한 안전한 항균물질임을 확인할 수 있었다. 또한 p. anomala K15는 에탄올 내성은 약하나 고농도의 당에서 저항성이 크므로 주조 발효초기 환경에서의 이상발효를 방지할 수 있을 것으로 사료되어진다.

• 한국콘텐츠학회논문지
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• 제9권2호
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• pp.326-338
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• 2009

유비쿼터스 비즈니스 환경은 기존의 e-비즈니스, m-비즈니스와는 다른 특성을 가지고 있다. 이는 u-비즈니스 모델을 개발할 때 유비쿼터스 컴퓨팅 기술의 특성과 유비쿼터스 비즈니스 환경을 고려해야 한다는 것을 의미한다. 본 논문에서는 유비쿼터스 비즈니스 패러다임의 핵심인 가치의 공동 창출 경험에 초점을 맞춘 u-비즈니스 모델 개발 프레임워크를 제시했다. 본 논문의 u-비즈니스 모델 개발 프레임워크는 8단계로 구성되어 있고 각 단계별 세부 절차를 구체적으로 제시했다. 새로운 비즈니스 패러다임 하에서 성공적인 비즈니스 모델을 발굴하고 수행하고자 하는 기업들에게 본 논문에서 제안한 u-비즈니스 모델 개발 프레임워크는 유용한 가이드라인을 제공할 수 있을 것으로 기대된다.

• Clinical and Experimental Pediatrics
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• 제53권2호
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• pp.136-145
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• 2010

Natural killer T (NKT) cell is a special type of T lymphocytes that has both receptor of natural killer (NK) cell (NK1.1, CD161c) and T cell (TCR) and express a conserved or invariant T cell receptor called $V{\alpha}14J{\alpha}18$ in mice or Va24 in humans. Invariant NKT (iNKT) cell recognizes lipid antigen presented by CD1d molecules. Marine-sponge-derived glycolipid, ${\alpha}-galactosylceremide$ (${\alpha}-GalCer$), binds CD1d at the cell surface of antigen-presenting cells and is presented to iNKT cells. Within hours, iNKT cells become activated and start to secrete Interleukin-4 and $interferon-{\gamma}$. NKT cell prevents autoimmune diseases, such as type 1 diabetes, experimental allergic encephalomyelitis, systemic lupus erythematous, inflammatory colitis, and Graves' thyroiditis, by activation with ${\alpha}-GalCer$. In addition, NKT cell is associated with infectious diseases by mycobacteria, leshmania, and virus. Moreover NKT cell is associated with asthma, especially CD4+ iNKT cells. In this review, I will discuss the characteristics of NKT cell and the association with inflammatory diseases, especially asthma.

• Journal of Microbiology
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• 제33권2호
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• pp.154-159
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• 1995

SH-14, a novel killer strain of Ustilago maydis was isolated in Korea. It has been reported in other papers that the toxin specificity and double-stranded RNA pattern of SH-14 strain were different from other laboratory strains. In this paper, we analyzed the biochemical characteristics of U. maydis SH-14 virus. Three distinctive peaks were isolated from CsCl density gradient, designated as top (T), intermediate (I) and bottom (B) components. We found that the densities of each components, 1.285, 1.408 g/cm$\^$3/, respectively, are very similar to those of other strains. As previously reported by the analysis of dsRNA in each component, the dsRNA segments are separately encapsidated. Capsid protein of SH-14 virus consists of two proteins about 70 Kd shown by SDS-PAGE analysis. Electron microscopic examination of the virus particles revealed that UmV particles are very similar in size and morphology to all isolates as well as all lab-strains. In order to test immunological cross reactivity of UmV, werstern bolt analysis was carriedout with antiserum against A8 virus. All capsid protein had positive reaction against A8 antibody which indicated that UmV are immunologically cross-reactive with all isolates from Korea. The results presented in this paper may show that UmV isolated from SH-14 strain has very similar biochemical characteristics to those of other UmV. However, the difference in the toxin specificity and the molecular weight of toxin protein from the SH-14 strain has us to conclude that U. maydis SH-14 strain is a new killer type.

• 한국미생물·생명공학회지
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• 제24권3호
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• pp.331-335
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• 1996

Characteristics of ethanol fermentation were investigated during the stationary culture of a killer yeast, Saccharomyces cerevisiae B15-1. Specific ethanol production rate reached the maximum level, 1.203 g-EtOH/g-cell-hr, at 150 g/l of the initial glucose concentration. No big differences were obtained in ethanol fermentability based on the initial sugar concentration below 150 g/l. When 200 g/l of sugar was used, fermentability dropped significantly. Although the final cell mass and the amount of ethanol produced were increased, their increase rates were declined according to the increase of initial sugar concentration. It was found that most of the sugar used below 150 g/l of concentration could be changed to ethanol. However, when 200 g/l of sugar was used, some of them remained in the media even after increase of cell mass and fermentation stopped. The ethanol yield was decreased when initial sugar concentration was high, and were increased when the amount of ethanol produced was increased and finally reached the plateau over 60 g/l of ethanol concentration.

• 대한미생물학회지
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• 제17권1호
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• pp.7-14
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• 1982

A model of induction of neoplasia by viruses has develpoed from experimental studies in animals and in cultured cells and oncogenic transformation of cells is the result of integration of viral genetic information into the cellular DNA. The evidence for these associations was derived primarily from seroepidemiologic investigation. However, data indicating that the relation between HSV-2 and cervical cancer fits the model derived from experimental animal studies are not yet sufficient to draw conclusion with regard to the etiologic role the virus in the development of the neoplasms. In other hand, the K562 tumor cell is highly susceptible target for natural killer cell lysis by the lymphocytes of human and murine periperal blood. The characteristics of this effector cell type has been investigated. A study on natural killer cell mediated cytotoxicity(NKMC) against $^{51}Cr$-K562 as target cell was studed in HSV-2 infected ICR mouse. We have studied for susceptibility of HSV-2 against mouse embryo fibroblast(MEF) cells and NKMC from HSV-2 infected mouse. The results obtained that the mouse embryo fibroblast cells culture, the number and size of the cells were markedly increased and formed a monolayers relatively rapid, and become complete monolayer sheet around 72 hrs. Duration of cytopathic effect on MEF cells was rapid by serial passing of HSV-2. The morphology of the HSV-2 infected cells appear to be mainly round, ovium, spindle form and some of them was forming large giant cells. The NKMC was decrease in mouse with HSV-2 and comparison between effector/target cells ratio as 25:1 and 50:1 respectively, the NKMC was found to be more significantly decreased than normal control we have concluded that the natural killer cell activity of the viral infected mouse was shown as a suppressed during the HSV-2 infection, day 7th and 14th.