• Journal of fish pathology
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• v.13 no.1
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• pp.1-6
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• 2000

The antibacterial activity of marine bacterium(Pseudomonas aeruginosa JYMB1-3) was assayed against Vibrio anguillarum with the aim of evaluating the possible use for biocontrolling fish disease as probiotic strain. Inhibition test on the solid medium showed that vibrios were especially sensitive to the JYMB1-3. Edwardsiella tarda, Streptococcus sp. and Staphylococcus epidermidis were also sensitive to that strain, however the antibacterial abilities were varied to the pathogens. The vibriostatic activity of antibacterial substance produced from $10^7$ cells of the strain for 24 hours was equivalent to $2.5{\mu}g$ of chloramphenicol.

• Korean journal of applied entomology
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• v.31 no.4
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• pp.475-479
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• 1992

The non-steroidal ecdysone agonist RH 5849 showed almost similar LC.o values( 18.1-26.5 ppm) at all stages of larval development of the tobacco cutworm, Spodoptera litura, when treated by a leaf-disk dipping method. The feeding-inhibition rate for the 4th instar larvae was dose-dependent, and simultaneously the weight gain of 3rd instar larvae ceased within 48 hour after feeding of the cabbage leafdisk dipped into RH 5849 4.2 ppm solution. The systemic larvicidal effect of RH 5849 was compared at cabbage and tobacco whole plant test. The $LC_{50}$ values below 20 ppm(mg/kg soil) was lasted for 15 days in cabbage, 30 days in tobacco respectively.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.634-637
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• 2012

In strawberry production, among others, the high incidence of diseases by pathogenic fungi resulting in the reduction of fruit yield and quality requires the development of eco-friendly management systems rather than chemical sprays to control them. The diameter of colonies grown in media at $25^{\circ}C$ for 5 days was measured to evaluate the in vitro inhibition of mycelial growth of 5 pathogenic fungi by irradiation with ultraviolet (UV-C, 264 nm). The mycelial growth of 5 pathogenic fungi was inhibited in potato dextrose agar (PDA) by the irradiation of UV-C for 1 hour a day, and was dramatically inhibited by the irradiation of UV-C for 9-12 h a day. The irradiation of UV-C for 9-12 h a day inhibited completely the growth of the late blight pathogen, Phytophthora cactorum. The irradiation distance of 40 to 50 cm was effective for the inhibition of mycelial growth of fungi. The mycelial growth of fungi without pre-incubation was inhibited strongly by UV-C irradiation compared to fungi pre-incubated for 2 days without light. The mycelia growth of Colletotrichum gloeosprioides and Fusarium oxysporum was inhibited strongly by UV-C irradiation in vegetable 8 juice agar compared to PDA.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.401-411
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• 2006

The cationic chitosan is prepared in this paper. This kind of cationic chitosan is a good retention aid for bleached hardwood pulp, the filler retention increased by 33.0% when the cationic chitosan (DS=1.27) dosage was 0.05%. Because many of the materials used in papermaking process are excellent microbiological nutrients, these nutrients will result in the growth of bacteria; uncontrolled growth of bacteria and fungi in the papermaking process adversely affects machine runnability. According to the standard methods of microbe growth inhibition test, cell counting was conducted after proper cultivated time. This paper explored the factors that affecting the cationic chitosan's antibacterial effect.

• Journal of Plant Biology
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• v.32 no.1
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• pp.41-49
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• 1989

Phenolic compounds such as gallic acid, ferulic acid, p-hydroxybenzoic acid, vanillic acid, salicylic acid, tannic acid, and hydroquinone were identified from the aqueous extracts and volatile substances of tomato plant by paper chromatography, high performance liquid chromatography and gas chromatography. The seed germination and seedling growth of the experimental species, lettuce and egg plant, were severely inhibited in 5$\times$10-3M of phenolic reagents identical to those identified from tomato plant. Germination and growth rate of test species in 5$\times$10-4M and 5$\times$10-5M were higher than that of 5$\times$10-3M. Therefore, 5$\times$10-3M of phenolic compounds would be assumed to be threshold concentration for allelopathic effects.

• Journal of Korean Medicine Rehabilitation
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• v.30 no.1
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• pp.31-45
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• 2020

Objectives In this study, we investigated the antimicrobial activity of a 70% ethanol extract of Maneung-hwan (MEH), which is prescribed by practitioners of oriental medicine for use against methicillin-resistant Staphylococcus aureus (MRSA). Methods The antibacterial activity of MEH against MRSA strains was evaluated using the disc diffusion method, broth microdilution method (minimal inhibitory concentration, MIC), checkerboard dilution test, and time-kill test. The mechanism of action of MEH was investigated by bacteriolysis using detergents or ATPase inhibitors Additionally, mRNA and protein expression were investigated by quantitative reverse transcription-polymerase chain reaction and western blot assay, respectively. Results The MIC of MEH was 25~1,600 ㎍/mL against all the tested bacterial strains. We showed that MEH extract exerts strong antibacterial activity. In the checkerboard dilution test, the fractional inhibitory concentration index of MEH in combination with antibiotics indicated synergism or partial synergism against S. aureus. The time-kill study indicated that the growth of the tested bacteria was considerably inhibited after a 24-h treatment with MEH and selected antibiotics. To measure the cell membrane permeability, MEH (3.9 ㎍/mL) was combined with Triton X-100 (TX) at various concentrations N,N-dicyclohexylcarbodimide (DCCD) was also tested as an ATPase inhibitor. TX and DCCD cooperation against S. aureus exhibited synergistic action. Accordingly, the antimicrobial activity of MEH in the context of cell membrane rupture and ATPase inhibition was assessed. Additionally, the expression of genes and proteins associated with resistance was reduced after exposing MRSA to MEH. Conclusions These results suggest that MEH possesses antibacterial activity and acts as a potential natural antibiotic against MRSA.

• Korean Journal of Pharmacognosy
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• v.21 no.2
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• pp.142-147
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• 1990

Yew cortex, twigs and leaves(Florida yew, Taxus floridana Nutt et Champ; Pacific, yew Taxus brevifolia Nutt(Taxaceae)) were extracted with MeOH and $CHCI_3$, respectively, and then the chloroform extract was fractionated by silica column chromatography. As biologically active substances, taxol derivatives were identified and several biological activity tests were followed. The results showed that it bad no antimosquito activity and inhibited the growth of root meristem of cress seeds. The chloroform ext. of Florida yew showed 91%, inhibition rate at 400 ppm and the taxol fractions of Pacific yew did 91% at 200 ppm, 94% at 100 ppm. In the antitumor activity tests in vitro against a cultured cell line of L1210 mouse leukemia, Pacific yew showed 99% inhibition rate at 1.0 ppm and Florida yew did 97% at 10 ppm.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.423-430
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• 2002

The effects of UV-B and commercial grade pesticides (butachlor and carbofuran), individually and in combination, were studied on a variety of physiological processes of rice field cyanobacterium Anabaena doliolum. Butachlor was found to be $2-12\%$ more toxic than carbofuran and $4-24\%$ than UV-B on the growth, photosynthesis, lipid peroxidation, membrane permeability, and nitrogenase activity of the test cyanobacterium. Of the three photosynthesis inhibitors, the butachlor-induced inhibition of whole chain was approximately 3 and $21\%$ higher than carbofuran and UV-B, respectively. Although the interaction of the stress factors caused a significant inhibition (P<0.01), it was still less than the additive effect on the parameters investigated, except for PSI.

• Archives of Pharmacal Research
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• v.27 no.9
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• pp.915-918
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• 2004

By bioassay-guided separation, an already known saponin, Pulsatilla saponin D was isolated from the root of Pulsatilla koreana Nakai as a antitumor component when evaluated by in vivo antitumor activity as well as in vitro cytotoxic activity test. It showed potent inhibition rate of tumor growth (IR, 82％) at the dose of 6.4 mg/kg on the BDF1 mice bearing LLC cells.

• YAKHAK HOEJI
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• v.28 no.2
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• pp.89-95
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• 1984

Microorganisms having beta-latamase inhibitory activity were selected from soil samples collected from 63 spots throughout the country. Screening procedures consist of two steps. Those are growth inhibition test of penicillinase-producing Staphylococcus aureus by double-layered agar plate containing penicillin G as a substrate, and that of penicillin sensitive Staphylococcus aureus ATCC 6538 in the similiar condition including penicillinase. Finally, a strain was selected from a soil sample of Pa-ju, Kyeong-gi Do. This strain was classified as a Streptomyces sp. by ISP(International Streptomycete Project) and Bergey's manual.