• Title/Summary/Keyword: Selective isolation

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Comparison of Four Different Isolation Media for Staphylococcus aureus (황색포도상구균 분리배지 비교)

  • Oh, Min-Hee;Kang, Seong-Il;Hong, Sang-Phil;Oh, Se-Wook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.5
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    • pp.606-611
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    • 2009
  • Performance test was carried out between selective media which are generally used in Staphylococcus aureus isolation from food. Sensitivity, determined according to the appearance of characteristic colonies when 30 different S. aureus strains were tested, resulted as Baird-Parker agar (RPF)> $Petrifilm^{TM}$ Staph Express plate> Baird-Parker agar> Mannitol salt agar. Also, the four different media showed the same selectivity because all tested media did not produce the false positive colonies. Recovery efficiency from the artificially inoculated foodstuff was almost the same for the tested media. Presumptive colonies were collected from the dried fishery product using Mannitol salt agar and collected strains were tested on 4 different selective agar. Almost presumptive strains did not show the false positive colonies except for S. carnosus ssp carnosus. This strain was identified as false positive colonies on Mannitol salt agar, Baird-Parker agar and $Petrifilm^{TM}$ Staph Express plate. But Baird-Parker agar (RPF) did not show the false positive colonies with the same strains. So, it was concluded that the Baird-Parker agar (RPF) has more higher selectivity than other tested media in this experiment.

Design of Flexible Reconfigurable Frequency Selective Surface for X-Band Applications (유연한 구조를 갖는 X-Band 재구성 주파수 선택구조 설계)

  • Lee, In-Gon;Park, Chan-Sun;Yook, Jong-Gwan;Park, Yong-Bae;Chun, Heung-Jae;Kim, Yoon-Jae;Hong, Ic-Pyo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.1
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    • pp.80-83
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    • 2017
  • In this paper, the X-band reconfigurable frequency selective surface having flexible geometry was proposed. The proposed RFSS is composed of patterns of cross-shaped loop with inductive stub, which can control the frequency response for C-Band and X-band by ON/OFF state of PIN diode. To minimize the parasitic effect and to obtain the high level of isolation between the unit cell of FSS and the bias circuit, we designed the grid type bias line on bottom layer through via hole. The measured transmission characteristics show good agreement with the simulation results and good stability of frequency response for different incident angles and curvatures of surface.

Isolation, Physico-chemical Properties and Biological Activity of Aurodox Group Antibiotics

  • Kim, Si-Kwan;Yeo, Woon-Hyung;Kim, Sang-Seock
    • Journal of Microbiology and Biotechnology
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    • v.6 no.4
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    • pp.265-269
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    • 1996
  • An isolate of Streptomyces rochei synonym was found to produce antibiotics with narrow anti-microbial spectrum against Streptococcus and Xanthomonas sp. Among the antibiotic complex produced by the strain, the main active compound was isolated, and its physico-chemical properties and biological activities were investigated. Molecular weight of the compound was determined to be ${[M+H]}^+$ 797 (FAB-MS). UV, $^1H \;and\;^{13}C$ NMR, and IR spectra suggested that the compound is a kirromycin-like aurodox group antibiotic. However, the anti-microbial spectrum of the main compound was slightly different from that of kirromycin. In addition, it was newly found that kirromycin showed a selective anti-microbial activity against Streptococcus pyogenes and phytopathogenic Xanthomonas sp.

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Highly Selective Synthesis of β-Amino Carbonyl Compounds over ZSM-5-SO3H under Solvent-free Conditions

  • Massah, Ahmad Reza;Kalbasi, Roozbeh Javad;Samah, Neda
    • Bulletin of the Korean Chemical Society
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    • v.32 no.5
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    • pp.1703-1708
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    • 2011
  • ZSM-5-$SO_3H$ efficiently catalyzed the one-pot three-component Mannich reaction of aldehydes, anilines, and ketones. ${\beta}$-Aminocarbonyl compounds were obtained in reasonable yields and excellent stereoselectivities when the reaction was carried out at room temperature under solvent-free conditions. Simple experimental conditions and product isolation procedure makes this protocol potential for the development of clean and environment-friendly strategy for the synthesis of ${\beta}$-amino-ketones. The catalyst was recovered and reused for subsequent runs.

Cytotoxic Phenylpropanoids from the Rhizomes of Alpinia galanga

  • NAM Joo-Won;KIM Sun-Jack;HAN Ah-Reum;LEE Sang Kook;SEO Eun-Kyoung
    • Biomolecules & Therapeutics
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    • v.13 no.4
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    • pp.263-266
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    • 2005
  • A bioassay-guided fractionation of the n-hexane and chloroform extracts of the rhizomes of Alpinia galanga led to the isolation of two active compounds, 1'S-1'-acetoxychavicol acetate (1) and p-coumaryl alcohol $\gamma$-O-methyl ether (2). 1'S-1'-acetoxychavicol acetate (1) exhibited significant cytotoxicity against all human cancer cell lines tested (A549; $IC_{50}$ 8.14, SNU 638; 1.27, HCTl16; 1.77, HT1080; 1.2, HL60; $IC_{50}$ 2.39 ${\mu}g/ml$), whereas p-coumaryl alcohol $\gamma$-O-methyl ether (2) showed selective cytotoxicity against the SNU638 cell ($IC_{50}$ = 1.62${\mu}g/ml$).

Isolation and Characteristics of Novel Ammonia Oxidizing Bacteria Brevundimonas diminuta (암모니아산화세균 Brevundimonas diminuta의 분리 및 암모니아 산화 특성)

  • Kwon, Hyuk-Ku;Jung, Joon-Oh
    • Journal of Environmental Health Sciences
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    • v.33 no.4
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    • pp.293-298
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    • 2007
  • The microorganism for ammonia gas removal was isolated from composting product. This was identified as Brevundimonas diminuta by morphological, biochemical characteristics study and 16S rDNA sequence analysis. Optimal incubation temperature for cell growth and oxidizing ability of $NH_4-N$ was $30^{\circ}C$ and optimal initial pH was 7. Glucose affected the growth of cell and the removal of $NH4^+$. The growth rate of the isolates were increased when grown in the presence of 0.05-1%(w/v) glucose in the selective medium and lurker increases in glucose concentration to 2% caused significant decreases in the cell growth and oxidizing ability of $NH4^+$.

Isolation and Characterization of Pseudomonas sp. T-1 Degrading Terephthalic Acid (Terphthalic Acid를 분해한는 Pseudomonas sp. T-1의 분리 및 특성)

  • 서승교
    • Journal of Environmental Health Sciences
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    • v.21 no.4
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    • pp.44-48
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    • 1995
  • 26 bacterial strains capable of growing on Terephthalic acid (TPA) in minimal medium were isolated from soil and wastewater by selective enrichment culture, and among them, one isolate which was the best in the cell growth and TPA degradation was selected and identified as Pseudomonas sp. T-1 by its characteristics. Cell growth almost revealed a stationary phase at 24 hrs after cultivation. Cell growth dramatically increased in a minimal medium containing 0.1% of TPA as a sole carbon source and TPA was not detected any more at 80 hrs after cultivation. Therefore, it is suggested that Pseudomonas sp. T-1 could be effectively used for the biological treatment of wastewater containing TPA.

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Isolation and Characterization of a Water-Soluble Polysaccharide from the Mycelia of Solid Cultured Agaricus blazei Murill

  • Chung, Ha-Yull;Cho, Young-Jun;Kim, Tae-Wook
    • Food Science and Biotechnology
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    • v.14 no.2
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    • pp.259-262
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    • 2005
  • A fraction (CMEx-AH-${\beta}$) of water-soluble polysaccharides, showing selective antitumor activities, was isolated from the mycelia of solid cultured Agaricus blazei Murill by hot-water extraction, ethanol precipitation, and series of chromatography. Chemical characteristics of CMEx-AH-${\beta}$, were as follows: carbohydrate content, 48%; monosaccharide composition, Man:Glu:Gal (2:93:5); molecular weight, $2{\times}10^5$; uronic acid content, 6.2%. Fundamental structure of CMEx-AH-${\beta}$, was deduced as ${\beta}-(1\;{\rightarrow}\;6)$-D-glucan with ${\beta}-(1\;{\rightarrow}\;3)$-D-glucosidic side chains based on results of methylation and $^{13}C$ NMR spectroscopic analyses.

Isolation and Characterization of Soil Strains Producing Glutaryl-7-Aminocephalosporanic Acid Acylase

  • Knang, Yong-Ho;Yoo, Ryong-Hoon
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.2 no.2
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    • pp.105-108
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    • 1997
  • A search was undertaken to screen microorganisms that produce an enzyme capable of deacylating glutary1-7-amincephalosporanic acid to 7-aminocephalosporanic acid in soil samples. The screening was carried out by preparing enrichment cultures containing glutary-7ACA and cephalosporin C as selective carbon sources. A non-${\beta}$-lactam model compound,, glutary-p-nitroanilide, was synthesized as a substrate suitable for the rapid screening of microorganisms isolated from the enrichment cultures. Two isolates exhibiting acylase activity, designated BY7.4 and BY8.1, were identified as strains of Pseudomonas species. Pseudomonas BY8.1 showed higher acylase activity toward G1-7ACA than Pseudomonas BY7.4. Environmental conditions for the optimal acylase activity of Pseudomonas BY8.1 were shown to be pH9 and 30$^{\circ}C$.

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A STUDY ON THE ISOLATION OF BLACK-PIGMENTED BACTEROIDES IN THE NECROTIC PULP (괴사치수에서의 Black-pigmented Bacteroides 균주분리에 관한 연구)

  • Choi, Han-Seuk;Yoon, Soo-Han;Chung, Jong-Pyoung
    • Restorative Dentistry and Endodontics
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    • v.11 no.1
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    • pp.97-103
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    • 1985
  • The purpose of this study was to compare Black-pigmented Bacteroides isolated from necrotic pulp with the presence or absence of eight symptoms associated with pulpal necrosis and to identify the proportion of each Black-pigmented Bacteroides species. The canal contents of fourteen traumatically and cariously necrotized teeth were sampled with a special technique and cultured aerobically and anaerobically for growth in blood agar plate and for Black-pigmented Bacteroides on selective blood agar plate. Each Black-pigmented Bacteroides species were identified by Gram's stain, hemolysis reaction, colony color and morphology and biochemical tests. The results were as follows; 1. 60.9 percent of the bacteria isolated were anaerobic and 39.1 percent were aerobic. 2. Four Black-pigmented Bacteroides species were isolated; B. loescheii (74.1%), B. denticola (11.1%), B. intermedius (7.4%) and B. gingivalis (7.4%). 3. Black-pigmented Bacteroides was found to be significantly related to sinus tract formation and exudate.

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