• Korean Journal Plant Pathology
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• v.11 no.3
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• pp.245-251
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• 1995

Nine hundred and ninety-two isolates of Botrytis cinerea were obtained from infected strawberries, tomatoes and cucumbers in Taejon, Gongju, Puyo, Nonsan and Kimhae in Korea. Six hundred forty-two (64.7%) isolates were benomyl resistant (BR), 245 (24.7%) were procymidone resistant (PR), and 105 (10.6%) were dichlofluanid resistant (DR). In the minimum inhibitory concentration (MIC) test, DR isolates showed mycelial growth on the PDA incorporated with 100 or 500 $\mu\textrm{g}$/ml of dichlofluanid, while dichlofluanid sensitive (DS) isolates did not grow on the PDA incorporated even with 10 $\mu\textrm{g}$/ml of dichlofluanid. Chemical concentrations for inhibition of spore germination were much lower than those for inhibition of mycelial growth. IC50 values, the effective concentrations for 50% inhibition of spore germination, for DR were 0.11~0.29 $\mu\textrm{g}$/ml, whereas they were 0.04~0.09 $\mu\textrm{g}$/ml for DS isolates. In comparison of fitness-related characteristics such as virulence, sclerotial formation, and sporulation, DR isolates were inferior to DS isolates. However, mycelial growth was little different between DR isolates and DS isolates.

• Korean journal of food and cookery science
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• v.28 no.1
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• pp.9-15
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• 2012

This study analyzed the antibacterial activity of a Rubus coreanum (Bokbunja) ethanol extract. The antimicrobial activity was determined by disc diffusion, minimum inhibitory concentration (MIC), and growth inhibition methods with seven kinds of bacteria related to foodborne illness (Bacillus cereus, Escherichia coli, Escherichia coli O157:H7, Listeria monocytogenes, Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella typhimurium). In the results, disc diffusions of the ethanol extract from R. coreanum (9.8-17.5 mm at $4,000{\mu}g/disc$) clearly showed the antimicrobial activity of the extract against all tested microorganisms. Rubus coreanum promoted an inhibitory effect as follows: E. coli O157:H7 > P. aeruginosa > L. monocytogenes > E. coli > S. aureus > B. cereus ${\geq}$ S. typhimurium. In the MIC test, R. coreanum showed high antimicrobial effect against L. monocytogenes at 500 ppm. Moreover, the R. coreanum ethanol extract showed strong growth inhibition against microorganisms, similar to the MIC results. These results show that a R. coreanum ethanol extract has powerful antimicrobial activity against all tested microorganisms, suggesting that R. coreanum will be useful as a potential natural preservative.

• YAKHAK HOEJI
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• v.20 no.1
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• pp.19-26
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• 1976

Sixteen compounds of 2-aminobenzothiazole derivatives were synthesized from alkyl ($C_{1-5}$) p-aminosalicylate by thiocyanation reaction. The NMR spectra of synthesized compounds showed that they were actually mixture of 5-hydroxy-6-alk-oxycarbonyl-2-aminobenzothiazole [alkoxy=methoxy(Ia), ethoxy (IIa), n-propoxy (IIIa), iso-propoxy (IVa), n-butoxy (Va), iso-butoxy (VIa), n-amoxy (VIIa), iso-amoxy(VIIIa)] and 7-(1b), ethoxy(IIb), n-propoxy(IIIb), iso-propoxy(IVb), n-butoxy(Vb), iso-butpxy (VIb), n-amoxy (VIIb), iso-amoxy (VIIIb)]. The mixtures of two isomeric benzothiazole were separated by two isomers varied with the kind of alkyl chain in alkyl p-aminosalicylate. These compounds were subjected to the test for antimicrobial activities using Staphylococcus aureus and Escherichia coli by tube dilutioin method. The seven compounds, Ia, IIa, IIIa, VIa, IIIb, IVb and Vb showed inhibition of the growth of S. aureus at the concentration of 10${\mu}$g/ml. As to the growth of E. coli, IVb, VIb, VIIb, and VIIIb were observed inhibition at the concentration of 1${\mu}$g/ml. Ia, IIa, IIIa, VIIa, Va, VIIIa, and IIb exhibited potential antimicrobial activities against showed inhibition of the growth of E.coli at the concentration of 100${\mu}$/ml.

• Microbiology and Biotechnology Letters
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• v.10 no.1
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• pp.33-37
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• 1982

The work has been carried out for the development of antifungal antibiotics possessing curative effect in the control of sheath blight disease of rice plant. Soil samples were collected from over 1600 spots throughout the country. More than 1300 specimens which seem to be the genus Streptomyces were isolated from the soil samples. Screening procedures consist of respective processes by four steps. Those are growth inhibition test in liquid culture, paper disk method, dendroid test and green house test. 102 isolates appeared to be active against Pellicularia sasakii when all specimens isolated were examined by the first growth inhibition test. Finally a strain of Streptomyces forming strong antifungal substances against P. sasakii was selected from a soil sample of Mt. Soyo, Kyeongi Province. Antifungal substances formed by the strain were isolated and purified from the culture broth and examined for antimicrobial activities as to be specific against fungi but not active on bacterial growth.

• Journal of Environmental Science International
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• v.14 no.12
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• pp.1129-1139
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• 2005

A series of experiments was conducted to identify the potential of five phytoplankton species as standard test species for marine ecotoxicological tests. The candidate phytoplankton species are Skeletonema costatum, Heterosigma akashiwo, Prorocentrum micans, Isochrysis galbana, and Tetraselmis suecica. Salinity tolerance and sensitivity on potassium dichromate as a reference material were identified. Toxicity of eleven ocean dumped sewage sludges and four red tide expellent extracts were estimated by the inhibition of population growth rates (PGR) of marine diatom S. costatum, While most species revealed relatively weak tolerance on salinity, T. suecica demonstrated the highest salinity tolerance ranged from $5\~35$ psu and the others $15\~35$ psu. H. akashiwo revealed the highest sensitivity as 72h $IC_{50}$=0.76mg/L and T. suecica the lowest as 72h $IC_{50}$=8.89mg/L on potassium dichromate. Sludge extracts from industrial waste, domestic sewage and livestock farm waste sludge showed high toxicity as 72h $IC_{50}$<$2\%$ and lowest toxicity from filtration bed sludge as 72h $IC_{50}$=$30.50\%$ NOEC (No Observed Effective Concentration) of sludge extract ranged from <$0.4\%$ to $1.6\%$ and this indicated high phytotoxicity of ocean dumped sewage sludge. The test sensitivity of phytoplankton PGR inhibition was much higher than those of marine rotifer Brachionus plicatilis mortality test and bioluminescent inhibition test by marine bacteria Vibrio fischeri, and comparable with the sea urchin (Strongylocentrotus intermedius) fertilization test. As a result the phytotoxicity test using phytoplankton PGR inhibition ($IC_{50}$) must be a useful tool for marine phyto-toxicological evaluation of ocean dumped materials.

• Korean Journal of Weed Science
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• v.17 no.4
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• pp.407-412
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• 1997

Allelopathic activity of methanol extract from medicinal plants was determined based on the inhibition of germination, shoot and root length of Echinochloa crus-galli. The response was depended on the source of extracts and concentrations. Of the 20 test plants tested, Cnidium officinale showed most inhibition according to germination, shoot and root length of E. crus-galli. Based on the plant parts, the root extract of C. officinale had more inhibitory effect on E. crus-galli than the stem+leaf extract. Phytotoxic effects of the root extract on E. crus-galli showed 75% inhibition of seed germination, 95% inhibition of shoot growth, and 100% inhibition of root growth at the concentration of 1g/petridish. Sequential partitioning of root extract with organic solvents with increasing polarity showed that the ethylacetate fraction had the greatest inhibitory effect on E. crus-galli. Germination was not inhibited at any rate of ethylacetate fraction but shoot and root growth, were significantly inhibited even at 2mg/petridish. This indicates that the most toxic phytotoxin present in the root extract may be moderate polar compound.

• Applied Biological Chemistry
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• v.41 no.8
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• pp.605-607
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• 1998

A total of 28 traditional drinks derived from 23 plant species in 19 families were tested for their in vitro growth-inhibiting effects against Bifidobacterium adolescents, Bifidobacterium bifidum, Lactobacillus acidophilus, Lactobacillus casei, Clostridium perfringens, and Escherichia coil using a paper disc agar diffusion method under anaerobic condition. The responses varied with bacterial strain, plant species and tissue sampled. In a test with C. perfringens at 5 and 10 mg/disc, potent growth inhibition was produced from the extracts of Eucommia ulmoides stems, Pinus densiflora leaves and shoots, Thea sinensis leaves (green and oolong teas) and Zingiber officinale roots. All materials tested did not adversely affect the growth of bifidobacteria, lactobacilli, and E. coli. These results may be an indication of at least one of the pharmacological activities of these plant-derived drinks.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.548-554
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• 2016

Optimal range of soil physical quality to enhance crop productivity or to improve environmental health is still in dispute for the upland soil. We hypothesized that the optimal range might be established by comparing soil physical parameters and their interactions inhibiting crop growth. The parameter identifying optimal range covered favorable conditions of aeration, permeability and root extension. To establish soil physical standard two experiments were conducted as follows; 1) investigating interactions of bulk density and aeration porosity in the laboratory test and 2) determining effects of soil compaction and deep & conventional tillage on physical properties and crop growth in the field test. The crops were Perilla frutescens, Zea mays L., Solanum tuberosum L. and Secale cereael. The saturated hydraulic conductivity, bulk density from the root depth, root growth and stem length were obtained. Higher bulk density showed lower aeration porosity and hydraulic conductivity, and finer texture had lower threshold bulk density at 10% aeration bulk density. Reduced crop growth by subsoil compaction was higher in silt clay loam compared to other textures. Loam soil had better physical improvement in deep rotary tillage plot. Combined with results of the present studies, the soil physical quality was possibly assessed by bulk density index. Threshold subsoil bulk density as the upper value were $1.55Mg\;m^{-3}$ in sandy loam, $1.50Mg\;m^{-3}$ in loam and $1.45Mg\;m^{-3}$ in silty clay loam for optimal soil physical quality in upland.

• Environmental Analysis Health and Toxicology
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• v.5 no.1_2
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• pp.45-50
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• 1990

In order to investigate the phototoxicity of five phenothiazine derivatives and one thioxanthen derivative were examined by using in vitro method based on growth inhibition of Candida albicans and red blood cell hemolysis. Effects of the test compounds on RBCs were monitored with a spectrophotometer and a drug PI in the Candida albicans was calculated on the basis of the lowest concentration giving a yeast-free zone. All phenothiazines phototoxic in the red blood cell hemolysis method were positive in the yeast test except promethazine. It was also observed that toxic photo-products were formed by perphenazine and chlorpromazine in the red blood cell hemolysis.

• Corrosion Science and Technology
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• v.9 no.3
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• pp.137-141
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• 2010

Sodium nitrite is widely used as one of the popular corrosion inhibitors for the protection of ferrous metal in closed cooling water system, such as a diesel engine and a chiller. The optimum treatment conditions are studied through laboratory tests using linear polarization resistance (LPR) technique. Corrosion rate of the carbon steel electrode could be maintained less than $2.5{\times}10^{-3}$ mmpy in the test condition of 500 ppm as ${NO_2}^-$, 200 ppm as $Cl^-$, $70^{\circ}C$ and pH 6.8. The pH control is confirmed not to be an important factor in the protection of carbon steel by sodium nitrite inhibitor. The addition of tolyltriazole was needed for the protection of the copper alloy in the sodium nitrite treatment system.