• KSBB Journal
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• v.4 no.2
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• pp.177-184
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• 1989

In separating mycelia from antibiotic fermentation broths, high permeate flux was obtained by cross-flow filtration using modified regenerated cellulose membrane. The flux was increased most effectively by increasing the flow rate. There existed a critical mycelium density (about 20% PMV) at which the highest flux was observed. In a batchwise concentration of the fermentation broth, the system suffered from a severe fouling problem, which was relieved drastically by applying diafiltration technique, although it increased the permeate volume. A combined concentration/diafiltration process was ideal in keeping relatively high flux together with a high product recovery yield. The best result was obtained by starting diafiltration after concentrating the broth to 20% PMV. By doing so, a 98% product recovery yield was achieved in the shortest time while keeping the permeate volume at a minimum level.

• KOREAN POULTRY JOURNAL
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• v.38 no.3 s.437
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• pp.128-131
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• 2006

대부분의 양계질병은 열과 통증을 수반하고 있지만, 개나 축우, 돼지와 같이 개체치료를 하지 못하기 때문에 보통 필드에서의 처치는 한계에 부딪치고 있는 실정이다. 특히 "열(Fever)"을 수반하는 동안의 항생체 처치는 계군을 예상되어지는 결과와 반대로 가게되는 경우도 있다. 이에 저자는 대군 농장들을 컨트롤 하기 위하여 여러 수단들을 찾게 되었는데 3년 정도 필드에서 적용하고, 그 결과 많은 호응을 얻게 되었다.

• Microbiology and Biotechnology Letters
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• v.19 no.3
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• pp.235-241
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• 1991

- A phthalic acid derivative and basic macrolide antibiotics, with antimicrobial activity against Gram positive bacteria and phytopathogenic fungi, respectively, were found to be produced by a strain 88-GT-161 identified as being a variety of Streptomyces melanosporofaciens. This paper describes an isolation procedure of the active compounds produced by this strain, their in vitro and in vivo (pot test) antimicrobial activites, and structure determination of one of the compounds, bis (2-ethylhexyl) phthalate, a phthalic acid derivative antibiotic. This compounds, upon cornparision with authentic bis (2-ethylhexyl) phthalate, dioctyl phthalate, revealed a difference in antimicrobial activity even though physico-chemical properties of these two compounds seemed indentical. This is the first report that dioctyl phthalate is biosynthetically produced by a Streptomyces sp. and shows antimicrobial activity.

• Journal of the Korean Chemical Society
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• v.38 no.8
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• pp.603-607
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• 1994

New cephalosporin antibiotics,7-[(3,4-dihydro-6-methoxycarbonyl-2,2-dimethyl-2H-1,4-thiazin-3-yl)acetamido]-3-[(substituted pyrimidin-2-yl)thiomethyl]-3-cephem-4-carboxylic acid derivatives(2a∼2d) were synthesized. These new cephalosporin derivatives were prepared by the introduction of pyridinylthiomethyl moiety in 3-position and thiazine group in 7-position of 7-ACA. Antibacterial activities of these compounds were examined and the relationship between structure and activities were studied. As the result, these compounds showed low antibacterial activities compared to cefotaxim used as control.

• Microbiology and Biotechnology Letters
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• v.10 no.3
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• pp.163-169
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• 1982

The possible effects in vivo on the duel usage of sinseng saponin and antibiotics were studied in vitro with microorganisms. Streptomycin.sulfate, kanamycin.sulfate and gentamycin.sulfate as being an aminoglycoside-antibiotic substance showed a general synergism by the interaction of ginseng saponin and these antibiotics. But kanamycin.sulfate and gentamycin.sulfate did not show a synergism in their original antimicrobial activity against Er-winia aroideoe. Chloramphenicol as being a benzene derivative displayed an increased antimicrobial activity by the interactions of ginseng saponin and this antibiotic against Salmonella typhi, Aerobacter aerogenes and the genus Serrotia. This antibiotic also showed the decreased antimicrobial activity against Bacillus subtilis, Bacillus megaterium and Escherichia coli, but did not show an uniform antimicrobial activity against others.

• YAKHAK HOEJI
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• v.30 no.2
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• pp.104-105
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• 1986

Full details of a modified Friedlander quinoline synthesis, which utilizes a Wadsworth-Emmons-Horner reaction as a key step, will be described.

• Korean Journal of Microbiology
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• v.24 no.3
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• pp.302-307
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• 1986

In order to investigate the properties of cephalospornase, a strong antibiotic resistant strain(H 112) was isolated from Pseudomonas aeruginose. The extracted enzyme had the following characteristics. Optimum temperature was 45.deg.C and unstable over $55^{\circ}C$, and optimum pH was 8.5. Cephalosporinase activity was not inhibited by metal ions such as $Mn^{++},\;Cu^{++}\;Fe^{++},\;Fe^{+++}$, and EDTA. But it was inhibited by some antibiotics such as carbenicillin, cefoxitin, cefotaxime, cefamandole, cefoperazone and SDS. The Vmax values of the enzyme were 100 at cephaloridine and 2.8 at cefoperazone, respectively. The molecular weight of cephalosporinase was estimated to be about $37.500{\pm}3,000$ by high performance liquid chromatography and nitrocefin reaction.

• Microbiology and Biotechnology Letters
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• v.15 no.5
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• pp.356-360
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• 1987

Effects of temperature on sisomicin fermentation were investigated. From the specific growth rates for logarithmic phase estimated at various temperatures, 8.2 kcal/g-mol was obtained as an activation energy for cell growth. It suggests that cell growth rate was limited by the internal diffusion layers for nutrients or oxygen caused by aggregated cells. Final antibiotic titer was decreased with in-creasing temperature, and it depended highly on the temperature to which cells were exposed during the logarithmic phase of growth. Temperature shifts during fermentation brought about an increase in antibiotic productivity.

• Horticultural Science & Technology
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• v.18 no.6
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• pp.811-814
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• 2000

Effects of kanamycin concentration on regeneration and rooting of transgenic 'McIntosh Wijcik' were investigated to establish the efficient Agrobacterium-mediated transformation system. Relatively high regeneration frequency of explants appeared even at the high concentration of $150mg{\cdot}L^{-1}$ kanamycin, but the regeneration frequency and the number of normal shoots decreased significantly at a concentration of higher than $100mg{\cdot}L^{-1}$ kanamycin in the gelrite-gellifying medium. Rooting response varied with the transgenic lines in the agar-solidifying medium supplemented with the different concentrations of kanamycin and they were grouped with the inhibition level at $30mg{\cdot}L^{-1}$ concentration. No correlation between copy number and root response was observed. The optimum concentrations of kanamycin for the regeneration of 'McIntosh Wijcik' apple in the medium gellified with gelrite and for indirect-selection of putative transformants in the rooting medium solidified with agar were found to be $100mg{\cdot}L^{-1}$ and $30mg{\cdot}L^{-1}$ respectively.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.172-172
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• 1994

1960년대 이후 광범위한 항암제로서 그 임상효과가 탁월한 물질로 알려진 Anthracycline계 항생물질이 화학구조상 B환의 Hydroquinone형에 의한 생체내 산화환원 반응으로 이해 심근 독성에 영향을 준다고 알려져 있다. 이에 본 연구실에서는 Anthracycline의 Aqlycone 부분 12번 탄소의 전자친화력을 증가시키는 11번 탄소의 Hydroxy group이 제거되고 9번 탄소의 Hydroxy group을 Amine으로 대체함과 동시에 4번 탄소의 Methoxy group이 제거된 보다 독성이 적을 것이라 생각되는 Anthracycline의 새로운 Aglycone 유도체를 Design 하여 전합성 하였다.