• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2007년도 International Meeting of the Microbiological Society of Korea
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• pp.109-111
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• 2007

• 한국환경보건학회지
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• 제36권3호
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• pp.191-198
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• 2010

The aim of this study was to determine the concentrations of air-borne microorganisms (bacteria, fungi, gram negative bacteria (GNB), endotoxins, and respirable suspended particles (RSPs), and their correlation with environmental parameters (temperature, humidity, and carbon dioxide levels) in duck houses. The mean concentrations of bacteria, fungi, and GNB were very high (> $10^6\;CFU/m^3$), and endotoxin levels exceeded $10^3\;EU/m^3$. Among the various work stages, in the task of receiving ducks, bacteria were $6.2{\times}10^6;CFU/m^3$, and GNB were $5.4{\times}10^6\;CFU/m^3$, while RSPs levels were $397.6\;{\mu}g/m^3$ and endotoxin levels were $47.2{\times}10^3\;EU/m^3$ in the task of dividing the ducks, and fungi were $4.9{\times}10^6\;CFU/m^3$ in the task of shipping the ducks. The concentrations of RSPs and endotoxins were significantly higher in tasks involving greater movement of ducks in the house, relative to tasks involving little movement of ducks (p<0.05). Further, with progression in growth of the ducks, the concentrations of bacteria, GNB, endotoxins, and RSPs were significantly increased. There was significant correlation between levels of GNB with bacteria (r=0.75) and fungi (r=0.86), endotoxins with RSPs (r=0.75), bacteria with fungi (r=0.39), and carbon dioxide with RSPs (r=0.38), bacteria (r=0.33), and endotoxins (r=0.31). These results suggest considerable respiratory hazard for farmers in these environments.

• 한국식품영양학회지
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• 제23권2호
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• pp.154-161
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• 2010

국화 정유의 식중독균에 대한 항균력을 검증하기 위해 국화 정유와 그 주성분인 camphor, chrysanthemyl alcohol, $\alpha$-pinene, $\gamma$-terpinene, ${\alpha}+{\beta}$-thujone를 10종 균주에 대하여 agar-well diffusion 분석법으로 생육 여부를 분서하였다. 실험 결과 국화 정유와 그 지표물질은 Gram 양성균과 음성균 모두에 대해서 탁월한 항균 효과가 나타났다. Agar-well diffusion 분석법 결과 국화 정유와 그 지표물질은 Gram 음성균보다 Gram 양성균에 대해서 강력한 활성을 나타내었다. 국화 정유의 minimum inhibitory concentration은 모든 균주에 대하여 5 ${\mu}g/m{\ell}$에서 균의 생장을 저해하는 효과가 나타났고, minimum bacteriocidal concentration은 S. choleraesuis와 L. monocytogenes에 대해서는 시험농도 내에서 사멸효과가 관찰되지 않았으나, 다른 균주에 대해서는 5~20 ${\mu}g/m{\ell}$에서 살균력이 나타났다. 또한 액체 배양중의 항균효과를 조사한 결과, 국화 정유와 그 지표물질은 24시간 동안 꾸준히 항균력이 지속되었다. 따라서 camphor, chrysanthemyl alcohol, $\alpha$-pinene, $\gamma$-terpinene, ${\alpha}+{\beta}$-thujone를 조성분으로 함유한 국화 정유성분은 10종의 식중독균에 대한 항균활성이 입증되어, 천연 항균제재로서 식품보존료로의 이용이 가능하리라 생각된다.

• BMB Reports
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• 제41권4호
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• pp.267-277
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• 2008

Insects mount a robust innate immune response against a wide array of microbial pathogens. The hallmark of the Drosophila humoral immune response is the rapid production of anti-microbial peptides in the fat body and their release into the circulation. Two recognition and signaling cascades regulate expression of these antimicrobial peptide genes. The Toll pathway is activated by fungal and many Gram-positive bacterial infections, whereas the immune deficiency (IMD) pathway responds to Gram-negative bacteria. Recent work has shown that the intensity and duration of the Drosophila immune response is tightly regulated. As in mammals, hyperactivated immune responses are detrimental, and the proper down-modulation of immunity is critical for protective immunity and health. In order to keep the immune response properly modulated, the Toll and IMD pathways are controlled at multiple levels by a series of negative regulators. In this review, we focus on recent advances identifying and characterizing the negative regulators of these pathways.

• 한국식품조리과학회지
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• 제13권3호
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• pp.330-337
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• 1997

4종류의 향신료(allspice, clove, oregano, thyme)를 액체배지에 0~2%(w/v) 첨가하여 멸균한 후 6종류의 식중독세균(Aeromonas hydraphila, Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus 196E, Salmonella typhimurium, Vibrio parahaemolyticus)을 $10^{5}$~$10^{6}$ cells/$m\ell$되게 접종하여 35$^{\circ}C$에서 24시간 배양하였다. 향신료의 종류와 농도에 따른 각 식중독세균에 대한 항균활성은 배양액의 생균수 변화로서 조사하였으며, 향신료의 농도가 증가할수록 식중독세균의 증식은 억제되었다. 액체배지에 첨가한 향신료의 농도 2% 범위내에서 Gram 양성균이 V. parahaemolyticus를 제외한 Gram 음성균에 비하여 증식이 크게 억제되었다. 향신료 중에서는 시험한 6종류의 식중독세균에 대하여 clove의 항균활성이 가장 우수하였으며, 다음으로는 allspice와 oregano가 우수하였다. 액체배지에 0.3%의 clove첨가로서 시험한 모든 식중독세균의 증식이 억제되었다. Kanagawa 반응 양성세균인 V. parahaernolyicus는 clove와 allspice를 첨가했을 때 시험한 타 균쥬에 비하여 증식이 가장 두드러지게 억제되었다. Thyme은 시험한 대부분의 세균에 대하여 가장 항균활성이 낮았던 반면에 clove는 1%를 첨가하였을 때 시험한 모든세균을 사멸시켰다.다.

• Journal of Dairy Science and Biotechnology
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• 제18권1호
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• pp.38-46
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• 2000

Since generalization of cold storage of raw and processed milk, psychrotrophic bacteria has become more important. The number present in raw milk is related to sanitary conditions during pro-duction and to length and temperature of storage before pasteurization. Growth of psychrotrophs In raw milk often reduces the quality of pasteurized products. Recently, some pathogenic bacteria like Listeria monocytogenes, Yersinia enterocolitica, Bacillus cereus are reported to grow at low temperature and cause food poisoning. The presence of gram positive psychrotrophic bacteria which can survive pasteurization can limit the shelf life of pasteurized milk during extended storage and the survival of heat stable proteases and lipases produced by gram negative psychrotrophic bacteria often brings about proteolytic damage to milk protein in the products. Therefore, in order to prevent the deteorioration of milk and milk products by the growth of psychrotrophs, it is necessary to cool down the temperature of raw milk as soon as possible after milking and to keep the temperature below 5t during storage at farm. As psychrotrophic bacteria become readily predominant in raw milk under refregeration, it can be considered to change the traditional incubating temperature for SPC from 30${\sim}$32$^{\circ}C$ to 25${\sim}$27$^{\circ}C$ at which the psychrotrophs prefer to grow. The psychrotrophic bacterial count(PBC) is of limited use in dairy industry, because of the 10 days incubation period. Although estimates of psychrotrophic bacteria may provide an acceptable shelf-life prediction, there is no single, generally acceptable rapid method for replacing the PBC at the moment. Consequently, faster method for esmating psychrotrophic bacteria has to be developed.

• Preventive Nutrition and Food Science
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• 제14권2호
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• pp.162-167
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• 2009

Various fermented foods were screened in search of food-grade bacteria that produce bacteriocins active against Gram-negative pathogens. An isolate from a mold-ripened cheese presented antibacterial activity against Gram-positive and Gram-negative bacteria. The most active isolate was identified as Lactobacillus casei by a biochemical method, ribotyping, and membrane lipid analysis, and was designated as OSY-LB6A. The cell extracts of the isolate showed inhibition against Escherichia coli p220, E. coli O157, Salmonella enerica serovar Enteritidis, Salmonella Typhimurium, and Listeria monocytogenes. The antibacterial nature of the cell extract from the isolate was confirmed by eliminating the inhibitory effects of acid, hydrogen peroxide, and lytic bacteriophages. The culture supernatant and cell extract retained antibacterial activity after heating at $60{\sim}100^{\circ}C$ for $10{\sim}20$ min. The activity of the cell extract from Lb. casei was eliminated by pronase and lipase. Finally, the cell extract showed a bactericidal mode of action against E. coli in phosphate buffer solution, but it was bacteriostatic in broth medium and food extracts.

• Membrane and Water Treatment
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• 제9권3호
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• pp.195-203
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• 2018

N-acetylcysteine (NAC) has been widely used as an initial mucolytic agent and is generally used as an antioxidant to help alleviate various inflammatory symptoms. NAC reduces bacterial extracellular polymeric substances (EPS) production, bacterial adhesion to the surface and strength of mature biofilm. The efficacy has been shown to inhibit proliferation of gram-positive and gram-negative bacteria. In membrane bioreactor (MBR) processes, which contain a variety of gram negative bacteria, biofilm formation has become a serious problem in stable operation. In this study, use of NAC as an inhibitor of biofilm contamination was investigated using the center for disease control (CDC) reactors with MBR sludge. Biomass reduction was confirmed with CLSM images of membrane surfaces by addition of NAC, which was more efficient as the concentration of NAC was increased to 1.5 mg/mL. NAC addition also showed decreases in EPS concentrations of the preformed biofilm, indicating that NAC was able to degrade EPS in the mature biofilm. NAC addition was also effective to inhibit biofilm formation by MBR sludge, which consisted of various microorganisms in consortia.

• 대한화학회지
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• 제65권3호
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• pp.203-208
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• 2021

As part of our attempt to discover novel active compounds against multi-drug resistant pathogens, we hereby report two new complexes of iron(III) with formulae: [Fe(L₁)₂(H₂O)₂]Cl₃ and [Fe(L₁)₂(L₂)(H₂O)]Cl₂ where L₁ = 1,10-phenanthroline (C₁₂H₈N₂) and L₂ = guanide (C₅H₄N₅O^-). The synthesized complexes were characterized using spectroscopic analysis (ESI-MS, ICP-OES, FT-IR, and UV-Vis), cyclic voltammetry, CHN analysis, gravimetric chloride determination, melting point determination, and conductance measurement. Octahedral geometries are assigned to both complexes. In vitro antibacterial activity was tested on two Gram-positive (Staphylococcus aureus, Streptococcus epidermidis) and two Gram-negative (Escherichia coli and Klebsiella pneumoniae) bacteria using the disc diffusion method. The complexes demonstrated appreciable activity against these pathogens. Interestingly, the [Fe(L₁)₂(L₂)(H₂O)]Cl₂ complex manifested a higher degree of inhibition against the drug-resistant Gram-negative bacteria than the commercially available drug, namely erythromycin.

• Archives of Pharmacal Research
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• 제12권4호
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• pp.259-262
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• 1989

The reaction of the sodium salts of 4-methoxy and 4, 7-dimethoxy 6-hydroxy benzofuran-5-carboxylic acid with ethyl chloroformate yields the corresponding dicarbethoxy derivatives. The N-substituted amides were obtained by treating the latter compounds with amines. The corresponding hydrazides were synthesized by the reaction of hydrazine hydrate on the dicarbethoxy derivatives which spontaneously cyclized to 5-substituted-2, 3- dihydro-1, 3, 4, -oxadiazol-2-one. Also the reaction with phenyl hydrazine has been studied. The dicarbethoxy derivatives and N-substituted amides were tested against Gram positive and Gram negative bacteria in vitro. Most of the compounds posses moderate or slight activity against Gram positive bacteria.