• Title/Summary/Keyword: E. coil

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Antimicrobial Effects of Organic Acids and Ethanol on Several Foodborne Microorganisms (식중독 미생물에 대한 유기산 및 에탄올의 항균활성 비교연구)

  • Ahn, Yong-Seon;Shin, Dong-Hwa
    • Korean Journal of Food Science and Technology
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    • v.31 no.5
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    • pp.1315-1323
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    • 1999
  • The antimicrobial effects of ethanol and organic acids(acetic, citric, lactic. propionic, tartaric acid), either alone or in combination against four foodborne microorganisms (Listeria monocytogenes, Salmonella typhimurium, Staphylococcus aureus and Escherichia coli O157:H7) in tryptic soy broth were determined. Area under the growth curve, minimum generation time, maximum growth rate, and detection time were measured by using automated turbidometer Bioscreen(Labsystem, Finland), for 24 hr at $30^{\circ}C$. All microorganisms were not grown at 7% ethanol in the media. The 0.1% propionic acid showed the strongest inhibitory effects against S. aureus, L. monocytogenes and E. coli O157 : H7 compared with other organic acids, whereas 0.01% organic acids did not show significant inhibitory effect against microorganisms tested (p > 0.01) except S. aureus. The combination of 1% ethanol and 0.01% organic acids were significantly more effective than alone on growth of S. aureus and L. monocytogenes(p < 0.01).

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Trichloro isocyanuric acid 와 Calcium hypochlorite에 의한 대장균 사멸특성 비교연구

  • Gang, Ja-Gyeong;Byeon, Dae-Jin;Kim, Eung-Su
    • 한국생물공학회:학술대회논문집
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    • 2000.04a
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    • pp.430-433
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    • 2000
  • The disinfection effects of Trichloro isocyanuric acid (TICA) and Calcium hypochlorite (Cal-hypo) against E. coli' in aqueous suspension were compared at various concentrations of disinfectants as well as exposure times. When E, coil($^{\sim}10^7$ CFU/ml) were exposed by TICA and Cal-hypo (12 ppm each), 90% of the initial cells were reduced in 4 sec and 390 sec, respectively. Although Cal-hypo lost its disinfection capability in about 1 hr under the sun light, TICA maintained its effect up to 6 hrs. This comparative studies clearly demonstrate that TICA is more effective than Cal-hypo in terms of sterilizing E. coli as well as maintaining the disinfection effects.

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Probiotic Properties of Lactobacillus salivarius Isolated from Chicken Intestines (병아리의 장에서 분리한 Lactobacillus salivarius의 생균제로서 특성)

  • 박홍식;이지혜;엄태붕
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.5
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    • pp.1003-1009
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    • 1999
  • For the isolation of probiotics which may be used for the human beings and animals, we have screened the microorganisms from chicken intestines which have acid and bile tolerance and the growth inhibition of pathogenic E. coli and Salmonella typhimurium. Among them, a strain which was identified as Lactobacillus salivarius had around 66% of survival after 2h incubation in the artificial gastric juice and 9% of survival after 24h incubation in the presence of 0.3% bile salts, and showed complete inhibition against both path ogenic E. coli and Salmonella typhimurium after 24 h coincubation. Its storage stability after lyophilization could be improved by adding polyvinylpyrrolidone.

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$SiO_2$ Etching in $C_4F_{8}$ Plasma by E-ICP ($C_4F_{8}O_2$ 공정기체와 E-ICP를 이용한 산화막 식각)

  • 송호영;조수범;이종근;오범환;박세근
    • Proceedings of the IEEK Conference
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    • 2001.06b
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    • pp.197-200
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    • 2001
  • Novel Enhanced Inductively Coupled Plasma is applied to etch $SiO_2$. Effect of $O_2$ or Ar addition to $C_{4}F_{8}$ gas is monitored by Optical Emission Spectroscopy and Quadrupole Mass Spectrometer. It is fund that Ar or $O_2$ dilution to $C_{4}F_{8}$ increases F emission intensity and decreases $CF_2$ intensity. However, the ac frequency to the Helmholtz coil decreases the F intensity and thus increases $CF_2$/F ratio. By adjusting the ac frequency, the optimum etch rate and PR to $SiO_2$ selectivity can be obtained in E-lCP.

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Crystallinity of yellow colored silkworm variety cocoons

  • Park, Bo Kyung;Nho, Si Kab;Um, In Chul
    • International Journal of Industrial Entomology and Biomaterials
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    • v.38 no.2
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    • pp.51-55
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    • 2019
  • The structure and properties of silk polymers (fibroin and sericin) can be satisfactorily controlled by choosing a suitable silkworm variety and, hence, this parameter (i.e., silkworm variety) has attracted increasing attention. A previous study reported that the crystallinity of white colored silkworm cocoons depends on the silkworm variety. In the present study, sixteen yellow colored silkworm variety cocoons were produced and their molecular conformation and crystallinity were investigated. The conformation of the silkworm cocoons varied with the silkworm variety. Most cocoons exhibited ${\beta}$-sheet conformation, although random coil and ${\beta}$-sheet conformations co-existed in some cocoons (e.g., 21 and D90). The crystallinity of the silkworm cocoons varied with the silkworm variety and the measurement position of the cocoon (i.e., outer surface or inner surface). However, the difference in the crystallinity indices of the outer and inner surfaces comprising the cocoons varied with the silkworm variety, but was <2% for all cocoons, except for MAL.

Molecular Cloning and Expression of Bacillus pasteurii Urease Gene in Escherichia coli (B. pasteurii Urease 유전인자의 E. coli의 복제와 발현)

  • Kim, Sang-Dal;John Spizizen
    • Microbiology and Biotechnology Letters
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    • v.13 no.3
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    • pp.297-302
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    • 1985
  • The 7.1 Mdal Xbaf fragment of Bacillus pasteurii ATCC 11859 containing gene for urease was inserted into the Xbal site of bifunctional plasmid pGR71, and its urease gene was cloned and expressed in E. coil RRI. But the cloned gene was not expressed in Bacillus subtilis BR151 in consequence of deletion of inserted DNA fragment. The recombinant plasmid thus formed was named pGU66. The restriction map of the plasmid pGU66 was determined, and the size of the plasmid was estimated to be 12.6 Mdal by double digestion of restriction enzymes of the plasmid. The urease of the cloned strain was accumulated in periplasmic space and very similiar to that of donor strains in their enzymatic properties.

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Fabrication of Planar Vibratory Gyroscope Using Electromagnetic Force (전자력을 이용한 평면 진동형 자이로스코프의 제작)

  • Lee, Sang-Hun;Kim, Yong-Kweon
    • Proceedings of the KIEE Conference
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    • 1993.11a
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    • pp.195-197
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    • 1993
  • In this paper, a planar vibratory gyroscope is designed and fabricated in macro model. Elementary experiment and test are done for micro model. This gyroscope has a double gimbal structure with an active dimension $80{\times}120{\times}1\;mm^3$. Outer gimbal vibration is generated by electromagnetic force using ferrite E-core wounded by coil. Inner gimbal vibration is detected by inductive sensor. It is demonstrated' that mechanical and electrical symmetries are important for improvement of vibratory gyroscope.

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Tokamak Super Conductor Coil Quench Protection System (토카막용 초전도 코일 보호장치-Quench System)

  • Yoo, H.Y.;Sim, E.Y.;Lee, S.Y.;Jang, Y.H.
    • Proceedings of the KIPE Conference
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    • 2010.07a
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    • pp.279-280
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    • 2010
  • 본 논문의 Quench System은 KSTAR의 토카막의 초전도 코일인 플로이달 코일과 토로이달 코일의 보호장치로서 코일에서 Arc 발생 시 코일과 전원을 차단, 분리하고 코일전류를 Dump 저항으로 급속하게 방전시켜, 코일을 보호하는 System 이다.

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HBV-X 단백질과 간세포 단백질간의 상호작용

  • 윤영대;김민재;김학대;이현숙;허윤실
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1993.04a
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    • pp.64-64
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    • 1993
  • 당해년도에는 HBV-X와 결합하는 상대 단백질을 탐색하는 것이 주목적이다. 이 목적으로 1) 우선 생물학적 활성을 보유하는 X-단백질을 E. coil system에서 다량으로 생산하는 공정을 확립하였으며 2) 이 X-단백질을 labelling한 후 Probe로 사용하여 liver cell내에 존재하는 43Kd, 48Kd, 55Kd, 100Kd의 단백질이 HBV-X에 결합하는 것을 확인하였으며 3) liver cell expression library를 screening하여 HBV-X와 결합하는 단백질을 coding하는 유전자를 cloning하여 현재 각 clone들을 규명하고 있는 중이다. 4) 또한 암억제 유전자 산물인 p53과 X-단백질과의 상호작용을 발견하였다. 이러한 결과는 X-단백질이 간암의 발생에 작용하는 기작을 설명할 수 있는 중요한 발견이다.

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