• 접착 및 계면
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• 제18권1호
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• pp.13-24
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• 2017

본 연구에서는 50 wt%의 매우 높은 담지량과 70%의 높은 고형분을 가지면서도 물속이나 다양한 제품에 나노 입자 형태로 분산이 가능한 새로운 형태의 소수성 항균 물질 담지 나노 입자를 제조하였다. 실란 기능화 양친성 고분자 전구체(Alkoxysilane-functionalized Amphiphilic Polymer Precursor; 이하 AAPP)와 다양한 실란 화합물을 이용하여 전형적인 Hydrolytic Sol-Gel 공정으로 제조된 수분산 유-무기 하이브리드 나노 입자들을 제조하고, 이를 이용하여서 나노 침전법을 사용하여서 소수성 항균물질을 고함량으로 담지할 수 있는 새로운 공정으로 소수성 항균물질인 Eugenol이 담지된 유-무기 하이브리드 형태의 나노입자 제조하였다. 나노 입자 제조시 제조 조건의 변화에 따른 나노 입자들의 크기, 담지량, 항균 활성 및 방출거동 등에 영향을 미치는 인자들을 조사하였다. 나노 입자의 종류에 관계없이 Minimal Inhibitory Concentration (MIC)는 50 mg/ml로 동일하였고, 모든 균주에서 99 %에 해당하는 우수한 항균력과 Pseudomonas aeruginosa (PSE)를 제외하고는 2주 이상의 항균 지속력을 나타내었다. 특히, Tetraethoxysilane (TEOS)를 첨가한 경우에는 견고한 무기물 도메인으로 인해 가장 높은 담지량 (50 wt.%)과 서방출 (Sustained release)을 나타내었고, Hexanediol (HD)을 첨가한 경우에는 HD 자체의 항균력과 용매로서의 역할도 하였기 때문에 가장 높은 항균력과 70%의 고형분을 나타내었다.

• 한국산학기술학회논문지
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• 제20권5호
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• pp.102-108
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• 2019

티트리 (Melaleuca alternifolia, Tea tree)는 terpineol-4, cineol, cymene, sesquiterpenes 등을 함유하여 살균 효과와 피부 보습효과를 지니고 있으며 또한, 여드름 염증 완화, 비듬 치료, 통증 완화, 우울증 해소 등의 특성을 가지고 있다. 본 연구에서는 티트리를 유기용매 (Methanol, Dichloromethane, Ethyl acetate) 및 열수추출법을 이용하여 물질을 추출하였으며, 각 추출액에서 나타나는 항균 및 항진균 활성을 확인하였다. 항균 활성 검증은 9종의 병원성 미생물 (Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa, Vibrio parahaemolyticus)을 대상으로 실시하였으며, 항균 활성 검증에 일반적으로 사용되는 disc diffusion법을 이용하여 추출물의 항균 활성을 확인하였다. 항균활성 검증을 통하여 ethyl acetate 분획추출물과 methanol 분획추출물에서 V. parahemolyticus와, S. aureus에 대한 항균활성을 확인하였다. 또한, 최대 활성을 나타내었던 V. parahaemolyticus를 대상으로 각 분획추출물 및 열수추출물의 항균활성을 확인하였으며, 10 mg/mL 농도로 처리하였을 때 99.9 % 이상의 항균활성을 확인하였다. 항진균활성의 경우, 균종에 따른 차이는 있으나 진균류에 대한 약 45시간 이상의 보존력을 확인하였다. 본 연구를 통해서 티트리 열수추출물과 메탄올 추출물의 V. parahaemolyticus에 대한 항균 활성을 확인하였으며, 추가적인 연구를 통해 항균제 및 항진균제로써의 개발 가능성을 확인하고자 한다.

• 폴리머
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• 제30권5호
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• pp.402-406
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• 2006

천연 옻 나무에서 추출되는 항균물질 우르시올을 폴리우레탄 발포체 성형 시스템에 도입하여 항균 폴리우레탄 발포체를 제조하였다. 항균물질 우르시올 첨가량을 증가시키는 경우 발포체 성형 반응성이 약간 저하되는 것이 관찰되었으나 기계적 물성 측면에서는 항균물질 미처리 발포체와 비교하여 큰 물성저하는 관찰되지 않았다. 반면 항균성 측면에서는 항균물질 미처리 발포체에 비하여 초기 균수 대비 균수의 성장성이 감소되는 것을 확인할 수 있었다.

• Molecules and Cells
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• 제19권3호
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• pp.365-374
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• 2005

To find potential targets of novel antimicrobial agents, we identified essential genes of Streptococcus pneumoniae using comparative genomics and allelic replacement mutagenesis. We compared the genome of S. pneumoniae R6 with those of Bacillus subtilis, Enterococcus faecalis, Escherichia coli, and Staphylococcus aureus, and selected 693 candidate target genes with > 40% amino acid sequence identity to the corresponding genes in at least two of the other species. The 693 genes were disrupted and 133 were found to be essential for growth. Of these, 32 encoded proteins of unknown function, and we were able to identify orthologues of 22 of these genes by genomic comparisons. The experimental method used in this study is easy to perform, rapid and efficient for identifying essential genes of bacterial pathogens.

• Journal of Microbiology and Biotechnology
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• 제16권4호
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• pp.623-632
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• 2006

To find potential targets of novel antimicrobial agents, we identified essential genes of Staphylococcus aureus N315 by using comparative genomics and allele replacement mutagenesis. By comparing the genome of S. aureus N315 with those of Bacillus subtilis, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, and Streptococcus pneumoniae, a total of 481 candidate target genes with similar amino acid sequences with at least three other species by >40% sequence identity were selected. of 481 disrupted candidate genes, 122 genes were identified as essential genes for growth of S. aureus N315. Of these, 51 essential genes were those not identified in any bacterial species, and 24 genes encode proteins of unknown function. Seventeen genes were determined as non-essential although they were identified as essential genes in other strain of S. aureus and other species. We found no significant difference among essential genes between Streptococcus pneumoniae and S. aureus with regard to cellular function.

• Molecular & Cellular Toxicology
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• 제3권4호
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• pp.222-230
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• 2007

Some drugs may be limited in their clinical application due to their propensity towards their adverse effects. Toxicogenomic technology represents a useful approach for evaluating the toxic properties of new drug candidates early in the drug discovery process. Nitrofurantoin (NF) is clinical chemotherapeutic agent and antimicrobial and used to treatment of urinary tract infections. However, NF has been shown to result in pulmonary toxic effects. In this research, we revealed the changing expression gene profiles in BEAS-2B, human bronchial epithelial cell line, exposed to NF by using human oligonucleotide chip. Through the clustering analysis of gene expression profiles, we identified 136 up-regulated genes and 379 down-regulated genes changed by more than 2-fold by NF. This study identifies several interesting targets and functions in relation to NF-induced toxicity through a gene ontology analysis method including biological process, cellular components, molecular function and KEGG pathway.

• The Plant Pathology Journal
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• 제21권4호
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• pp.328-333
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• 2005

Paenibacillus elgii SD17 (KCTC $10016BP^T$=NBRC $100335^T$) was recently reported as a new species. Based on its inhibitory activity to Thanatephorus cucumeris AG1-1, strain SD17 was further evaluated for its potential as a biocontrol agent against soil-borne diseases of turf grasses in Korea. P. elgii SD17 showed a broad spectrum of antimicrobial activity in vitro test and suppressed development of turf grass diseases; Pythium blight caused by Pythium aphanidermatum and brown patch caused by T. cucumeris AG1-1 on creeping bentgrass (Agrostis palustris) in the growth chamber tests. Under a condition for massive culture in a 5,000 L fermenter, P. elgii SD17 reached $6.4{\times}10^8$ spores/ml that resulted in approximately $1.0{\times}10^7$ cfu/g when formulated into a granule formulation (GR) using the whole culture broth instead of water. Using the GR formulation, biocontrol activity of P. elgii SD17 was confirmed. In the growth chamber tests, the GR formulation was effective against brown patch and Pythium blight with similar level of disease severity compared to each of the standard fungicides at the application rates of 10 g/$m^2$ or above. In the field tests, compared to each untreated control, the GR formulation also effectively controlled Pythium blight, brown patch and large patch at all the application rates of 5, 10 and 20 g/$m^2$, respectively, without significant response by the application rates. However its performance was inferior to each of the standard chemical fungicides. Based on these results, we consider this GR formulation of P. elgii SD17 as an effective biocontol agent to suppress Pythium blight, brown patch and large patch of turf grasses in Korea.

• Archives of Pharmacal Research
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• 제21권3호
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• pp.310-314
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• 1998

DW-116 is a new fluoroquinolone antimicrobial agent with a broad spectrum. In order to elucidate the resistance mechanism to DW-116 in Acinetobacter spp. bacteria, total chromosomal DNA was isolated from 10 strains of Acinetobacter spp. resistant to DW-116. Quinolone resistance determinant region (QRDR) of DNA gyrase gene was amplified by PCR. The 345 bp nucleotide fragment yielded was inserted into pKF 3 which was used as the vector. Comparisons of the DNA sequences of 8 strains with that of the wild type strain revealed a Ser-83 to Leu mutation in mutants and all ten strains contained one silent mutation$(T{\rightarrow}G)$in QRDR. From Acinetobacter MB4-8 strain, DNA gyrase was isolated and purified, through novobiocin-sepharose, heparin-sepharose affinity column chromatography. The enzyme was composed of two subunits and the molecular mass of subunits A and B were 75.6 and 51.9 kDa, respectively. The supercoiling activity of the reconstituted DNA gyrase composed of subunit A from Acinetobacter MB4-8 and subunit B from E. coli was not inhibited by $128{\mu}\textrm{g}$ml of ciprofloxacin. It might be said that one of the resistance mechanisms to DW-116 in Acinetohacter MB4-8 was subunit A alteration of DNA gyrase.

• Journal of Microbiology and Biotechnology
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• 제22권5호
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• pp.674-683
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• 2012

A new strain, SD12, was isolated from tannery waste polluted soil and identified as Pseudomonas aeruginosa on the basis of phenotypic traits and by comparison of 16S rRNA sequences. This bacterium exhibited broad-spectrum antagonistic activity against phytopathogenic fungi. The strain produced phosphatases, cellulases, proteases, pectinases, and HCN and also retained its ability to produce hydroxamate-type siderophore. A bioactive metabolite was isolated from P. aeruginosa SD12 and was characterized as 1-hydroxyphenazine ((1-OH-PHZ) by nuclear magnetic resonance (NMR) spectral analysis. The strain was used as a biocontrol agent against root rot and wilt disease of pyrethrum caused by Rhizoctonia solani. The stain is also reported to increase the growth and biomass of Plantago ovata. The purified compound, 1-hydroxyphenazine, also showed broad-spectrum antagonistic activity towards a range of phytopathogenic fungi, which is the first report of its kind.

• 보존과학연구
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• 통권22호
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• pp.5-25
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• 2001

The germicidal and insecticidal properties of volatile components extracted from star anise(Illicium verum Hooker filius) and clove (Eugenia caryophyllata THUNBERG)were evaluated against five microorganisms and three insects for the purpose of developing biocidal active substances from medicinal plants. The volatile components of star anise and clove showed strong antimicrobial effect against Aspergillus niger, Penicillium funiculosum, Mucor hiemalis, Trichoderma viride, and Aureobasidium pullulans. The extracts of each medicine also showed insecticidal effects against Sitophilusoryzae L., Lyctus linearis GOZE, and Reticulitermes spertus kyushuensis Morimoto. Fumigant toxicities to adult insects were determined. In the case of fumiganttoxicity, the extract of star anise showed 100% mortality against R. spertus, S.oryzae, and L. linearis at rates of $2.5\mu\ell$, $50\mu\ell$, $250\mu\ell$/filter paper, respectively but showed no killing effects by clove. The volatile components of star anise and clove were investigated by means of GC/MS. The main constitute, anethole among 20components from star anise and eugenol among 9 components from clove were identified. The mixture of star anise and clove as the volume ratio of 2 : 1 showed higher properties for antimicrobial and insecticidal effect than each volatile component. A. niger was inhibited by the mixture(125ml/$m^3$) for up to 10 days of exposure. Also, from the result of observing state change of organic materials by volatile extracts of star anise and clove, volatile extracts effects have no effect on natural organic materials of organic cultural properties and can be used as biological control agent. As research contents as above, the insecticidal and germicidal agents from star anise and clove and the mixture of them were more efficient and high level to prevent biological damage for conservation of organic cultural properties. So they may be used in new development of biologicalinsecticidal and germicidal agents for conservation of cultural properties.