• The Korean Journal of Pesticide Science
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• v.4 no.4
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• pp.72-76
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• 2000

The study was conducted to investigate the developmental periods and effect of several insecticides on Hemiptarsenus sp., ectoparasitoid of Liriomyza trifolii. The mean length and width of egg were 0.5mm and 0.1mm. The mean length of larva, pupae, abult female, and abult male were 1.9mm, 2.0mm, 2.2mm, and 1.8mm, respectively. Developmental periods of Hemiptarsenus sp. from egg to larva at 15, 20, 25, $30^{\circ}C$ were 16.9, 8.8, 5.9, and 4.5 days, and those of pupa were 20.7, 9.7, 5.6, and 3.4 days, respectively. Based on these results, developmental threshold temperatures and effective temperatures were $9.5^{\circ}C$, 91.5 degree-days in egg-larval stage, $10.9^{\circ}C$, 142.3 degree-days in pupal stage. When several insecticides were evaluated to Hemiptarsenus sp. at the recommended concentrations, B.t WP, diflubenzuron WP, and cyromazin were negligiblly effective all life stages. Fipronil SC, cartap SP, spinosad GW were less toxic to larva and pupa, but highly toxic to adults. Abamectin EC was less toxic to all life stages, but inhibited oviposition of 50% more to Hemiptarsenus sp. female.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.429-436
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• 2005

As Sclerotinia sclerotiorum causing cucumber sclerotinia rot was the fastest in the mycelial growth at $25^{\circ}C$, its pathogenicity was strong at the same temperature among several temperatures. All the isolates of Sclerotinia sclerotiorum showed a strong pathogenicity against cucumber fruits, which was confirmed by a disk assay and a wound assay. A wound assay was superior to a disk assay to develop the assay system for assessing the fungicidal activity of several fungicides against Sclerotinia sclerotiorum. In a disk assay, it was very difficult to assess the fungicidal activity, because the pathogenicity of isolates used in the experiment was very strong. At 500 and $3.0{\mu}g/mL$, the activity of dichloflouanid and the mixture of carbendazim and diethofencarb against cucumber sclerotinia rot was 14.3 and 42.3%, respectively, by using a disk assay. However, at same concentration two fungicides showed the high controlling activity as 100 and 92.5%, through a wound assay in a laboratory. Also, the activity of two fungicides was good against cucumber sclerotinia rot in the greenhouse where cucumber plants were cultivated in the field, showing the control value as 91.1 and 82.9% at 100 and $825{\mu}g/mL$, respectively. All the isolates of Sclerotinia sclerotiorum from cucumber fruits sampled in the polyvinyl house were subjected to monitoring for the resistance to 7 fungicides. The $EC_{50}$ value of 7 fungicides was as follows: fenhexamid; $0.13{\mu}g/mL$, procymidon and iprodione; 0.18 and $0.24{\mu}g/mL$, carbendazim and the mixture of carbendazim and diethofencarb; 0.13과 $0.05{\mu}g/mL$, iminoctadine and dichlofluanid; 1.94 and $8.95{\mu}g/mL$. Ultimately it was not found that resistant isolates of Sclerotinia sclerotiorum were appeared in the field.

• Korean Journal of Microbiology
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• v.29 no.2
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• pp.85-91
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• 1991

.betha.-1,4-D-Glucan glucanohydrolase(EC 3.2.1.4;F-II-IV) purified from Trichoderma koningii was identified as a glycoprotein containing 9% carbohydrate. Isoelectric point of the enzyme was estimated to be 4.9 and molecular weight was determined to be approximately 58,000. The porducts of p-nitrophenyl-cellobioside ($PNPG_{2}$) catalyzed by the enzyme were p-nitrophenol(PNP) and p-nitrophenyl-glucoside($PNPG_{1}$). The Km value for $PNPG_{2}$ was estimated to be 0.97 mM in case of the holoside lindage and 10.4 mM in case of the aglycon linkage and their kcat values were $1.8*10^{5}$$ min^{-1}$ and $7.5*10^{5}$ $min^{-1}$ respectively. The product of p-nitrophenyl cellotriose($PNPG_{3}$) was only $PNPG_{1}$. The Km value for $PNPG_{3}$ was 69.5 .$\mu$M and kcat was $1*10^{8}$ $min^{-1}$ which implicates that the enzyme have higher affinity and higher hydrolysis rate toward $PNPG_{3}$ than toward $PNPG_{2}$. The enzyme showed its optimal activity at pH 4.0-4.5 and at 60.deg.C. The effect of gluconolactone on the activity toward $PNPG_{2}$ showed competitive inhibition pattern but glucose and cellobiose did not. The enzyme contained a high content of acidic and hydroxylated amino acids in contrast to basic amino acids.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.46-46
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• 2019

The experiments were performed in the Jinan (elevation: 300 meters above sea level), Jeollabuk-do. Seedlings (n = 63 per $3.3m^2$) of ginseng cultivar (Cheonpung, Yeonpung) were planted on April 10, 2015. Shading material of plastic film house was blue-white film. Before the Planting seedling, silicate (3 kg/10 a) or chitosan (40 kg/10 a) was fertilized and foliar sprayed on the leaves 1000 times dilution solution once a month from May to September every year. The growth results of 5-year old ginseng surveyed in 2018 are as follows. The average air temperature in the plastic film house was the highest at $26.6^{\circ}C$ and $26.5^{\circ}C$ in July and August, respectively, and the highest temperature was $40.5^{\circ}C$ in July. The maximum daily temperature of $35^{\circ}C$ or more was 30 days, with the average soil temperature being $24.9^{\circ}C$ in August. The chemical properties of the test soil are as follows. pH was 6.4~6.9 level and EC was 0.35~0.46 dS/m. The organic matter content was 33.5~41.4 g/kg, and available-P content was 251.9~306.8 mg/kg. Exchangeable cations contents, such as K, Ca and Mg were all the appropriate ranges. The soil microbial density surveyed by the dilution plate method was 10~50 times higher than that of control (Non-treatment) and actinomycete density was 3~6 times higher. Pathogens of the genus Fusarium by Metagenome analysis decreased 91.3% and 68.2% respectively in the foliar sprayed of chitosan and soluble-silicate. The light intensity (PAR) in the blue-white film plastic film house gradually increased until July and then decereased, with the average of light intensity in March-October was $120.3umol/m^2/s$. The growth of aerial parts such as plant height and stem length was better than non-sprayed group in silicate or chitosan treatments and Yeonpung cultivar was superior to the Cheonpung cultivar. The SPAD value was higher in Yeonpung cultivar foliar sprayed with soluble-silicate. The growth of underground parts such as root length and taproot length were better in chitosan and soluble-silicate treatment than control, especially in Yeonpung cultivar foliar sprayed with chitosan was good in taproot length and taproot diameter, and fresh weight of root was 60.1 g. Ginsenoside contents were 24.9 mg/g and 22.4 mg/g, in the Cheonpung cultivar foliar sprayed with soluble-silicate or chitosan respectively, 28% and 15% higher than control (19.5 mg/g). The incidence of disease by Alteraria panax and Botrytis cinerea was 3~9% and 4~9%, respectively. High temperature damage rate was 3~5%.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.05a
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• pp.150-151
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• 2003

Benzoyl peroxide is a high production volume chemical, which was produced about 1,375 tons/year in Korea as of 2001 survey. Most of them are used as initiators in polymerization, catalysts in the plastics industry, bleaching agents for flour and medication for acne vulgaris. The substance is one of the sever chemicals of which human and environmental risks are being assessed by National Institute of Environmental Research under the frame of OECD SIDS Program. It has a melting point of 104-106 $^{\circ}C$ and has solubility of 9.1 mg/1 in water at 25 $^{\circ}C$. The substance was readily biodegradable (83 % after 21days) and had toxic effects to aquatic organisms. The range of 72 hr-EbC50 (biomass) for algae was 0.07-0.44 mg/1 and 48 hr-EC50 for daphnia was 0.07-2.91 mg/1. The LC50 of acute toxicity to fish was 0.24-2.0 mg/1. Although the toxic effects of benzoyl peroxide to aquatic organisms were investigated, environmental monitoring data were not studied. In this study, distribution of the chemical among multimedia environment was estimated using EQC model based on the physical-chemical properties to evaluate the risk of benzoyl peroxide in environment. In level I, II calculation the chemical was distributed to soil (68.3 %) and water (28.7 %). In level III calculation it was primarily distributed to soil (99.9 %) and overall residence time of 3.4 years was estimated. Benzoyl peroxide could be persistent in environment.

• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.239-246
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• 2005

Some characteristics of two forms of glucoamylase (glucan 1 A-$\alpha$-glucosidase, EC 3. 2. I. 3) purified from Aspergillus coreanus NR 15-1 were investigated. The enzymes were produced on a solid, uncooked wheat bran medium of A. coreanus NR 15-1 isolated from traditional Korean Nuruk. Two forms of glucoamylase, GA-I and GA-II, were purified to homogenity after 5.8-fold and 9.6-fold purification, respectively, judged by disc- and SDS-polyacrylamide gel electrophoresis. The molecular mass of GA-I and GA-II were estimated to be 62 kDa and 90 kDa by Sephadex G-1OO gel filtration, and 64 kDa and 91 kDa by SDS-polyacrylarnide gel electrophoresis, respectively. The optimum temperatures of GA-I and GA-II were 60$^circ$C and 65$^circ$C, respectively, and the optimum pH was 4.0. The activation energy (Ea value) of GA-I and GA-II was 11.66 kcal/mol and 12.09 kcal/mol, respectively, and the apparent Michaelis constants (K_{m}) of GA-I and GA-II for soluble starch were found to be 3.57 mg/ml and 6.25 mg/ml, respectively. Both enzymes were activated by 1 mM Mn^{2+} and Cu^{2+}, but were completely inhibited by 1 mM N­bromosuccinimide. The GA-II was weakly inhibited by 1 mM p-CMB, dithiothreitol, EDTA, and pyridoxal 5-phosphate, but GA-I was not inhibited by those compounds. Both enzymes had significant ability to digest raw wheat starch and raw rice starch, and hydrolysis rates of raw wheat starch by GA-I and GA-II were 7.8- and 7.3-fold higher than with soluble starch, respectively.