• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2005.06a
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• pp.154-164
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• 2005

Saccharomyces cerevisiae KNU5377 is a thermotolerant strain, which can ferment ethanol from wasted papers and starch at 40$^{\circ}C$ with the almost same rate as at 30$^{\circ}C$. This strain showed alcohol fermentation ability to convert wasted papers 200 g (w/v) to ethanol 8.4% (v/v) at 40$^{\circ}C$, meaning that 8.4% ethanol is acceptable enough to ferment in the industrial economy. As well, all kinds of starch that are using in the industry were converted into ethanol at 40$^{\circ}C$ with the almost same rate as at 30$^{\circ}C$. Hyperthermic cell killing kinetics and differential scanning calorimetry (DSC) revealed that exponentially growing cells of this yeast strain KNU5377 were more thermotolerant than those of S. cerevisiae ATCC24858 used as a control. This intrinsic thermotolernace did not result from the stability of entire cellular components but possibly from that of a particular target. Heat shock induced similar results in whole cell DSC profiles of both strains and the accumulation of trehalose in the cells of both strains, but the trehalose contents in the strain KNU5377 were 2.6 fold higher than that in the control strain. On the contrary to the trehalose level, the neutral trehalase activity in the KNU5377 cells was not changed after the heat shock. This result made a conclusion that though the trehalose may stabilize cellular components, the surplus of trehalose in KNU5377 strain was not essential for stabilization of whole cellular components. A constitutively thermotolerant yeast, S. cerevisiae KNU5377, was compared with a relatively thermosensitive control, S. cerevisiae ATCC24858, by assaying the fluidity and proton ATPase on the plasma membrane. Anisotropic values (r) of both strains were slightly increased by elevating the incubation temperatures from 25$^{\circ}C$ to 37$^{\circ}C$ when they were aerobically cultured for 12 hours in the YPD media, implying the membrane fluidity was decreased. While the temperature was elevated up to 40$^{\circ}C$, the fluidity was not changed in the KNU5377 cell, but rather increased in the control. This result implies that the plasma membrane of the KNU5377 cell can be characterized into the more stabilized state than control. Besides, heat shock decreased the fluidity in the control strain, but not in the KNU5377 strain. This means also there's a stabilization of the plasma membrane in the KNU5377 cell. Furthermore, the proton ATPase assay indicated the KNU5377 cell kept a relatively more stabilized glucose metabolism at high temperature than the control cell. Therefore, the results were concluded that the stabilization of plasma membrane and growth at high temperature for the KNU5377 cell. Genome wide transcription analysis showed that the heat shock responses were very complex and combinatory in the KNU5377 cell. Induced by the heat shock, a number of genes were related with the ubiquitin mediated proteolysis, metallothionein (prevent ROS production from copper), hsp27 (88-fold induced remarkably, preventing the protein aggregation and denaturation), oxidative stress response (to remove the hydrogen peroxide), and etc.

• Microbiology and Biotechnology Letters
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• v.1 no.1
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• pp.51-57
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• 1973

2,2'-Methylene bis (3,4,6-trichloroacetoxy benzene) had been synthesized from Hexachlorophene. The eleven new derivatives -(2,2'Methylene bis [3,4,6-trichloro o-(${\beta}$-anilinopropionoxy) benzene]: m. p 173∼4$^{\circ}C$, C$\_$31/H$\_$24/N$_2$O$_4$Cl$\_$6/, 2,2' Methylene bis [3,4,6-trichloro (${\beta}$-Cyclohexylaminopropionoxy) benzene]: M. P, 187∼8$^{\circ}C$, C$\_$31/H$\_$36/N$_2$O$_4$Cl$\_$6/, 2,2'-Methylene bis [3,4,6-trichloro (${\beta}$-phenyl hydrazinopropionoxy) benzene]; M. P. 151∼3$^{\circ}C$, C$\_$33/H$\_$28/N$_2$O$_4$Cl$\_$6/, 2,2'-Methylene bis [3,4,6-trichloro (${\beta}$-o-toluidinopropionoxy) benzene]: M. P. 172∼3$^{\circ}C$, C$\_$33/H$\_$28/N$_2$O$_4$Cl$\_$6/, 2,2'-Methylene bis [3,4,6-trichloro (${\beta}$-p-todudinopropionoxy) benzene]: 153∼4$^{\circ}C$, C$\_$33/H$\_$28/N$_2$O$_4$Cl$\_$6/, 2,2'-Methylene bis [3,4,6-trichloro (${\beta}$-o-chloro anilinopropionoxy) benzene]: 170∼2$^{\circ}C$, C$\_$31/H$\_$27/N$_2$O$_4$Cl$\_$8/, 2,2'-Methylene bis [3,4,6-trichloro (${\beta}$-p-sulfamilinopropionoxy) bengene]: M. P. 310-5$^{\circ}C$, C$\_$31/H$\_$24/N$_2$S$_2$O$\_$10/Cl$\_$8/, 2,2'-Methylene bis [3,4,6-trichloro (${\beta}$-piperidinopropionoxy) benzene]: M. P. 168∼2$^{\circ}C$, C$\_$29/H$\_$32/N$_2$O$_4$Cl$\_$6/, 2,2'-Methylene bis (3,4,6-trichloro (${\beta}$-morpholinopropionoxy) benzene]: M. P. 226∼8$^{\circ}C$, C$\_$27/H$\_$28/N$_2$O$\_$6/Cl$\_$6/, 2,2'-Methylene bis (3,4,6-trichloro (${\beta}$-2-amino pyridino propionoxy) benzene]; M. P. 145∼6$^{\circ}C$, C$\_$29/H$\_$22/N$_4$O$_4$Cl$\_$5/-were synthesized by Mannichs reaction as potential antimicrobial agents and their antimicrobial activity were tested against Bacillus subtilis, Pseudomonas ovalis, Escherichia coli, Staphylococcus aureus, aerogenes, Bacillus Acerobacter Polymyxa, Bacillus brevis, Streptomyces griseus, Candida troficalis, Rhodotorula glutinis, Candida utilis, Hansenula anamola, Saccharomyces cerevisiae in vitro. Among them, compounds of benzylamine and p-toludine showed an effective antimibrobial activity againt Bacillus subtilis and Pseudomonas ovalis.

• Microbiology and Biotechnology Letters
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• v.1 no.1
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• pp.43-50
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• 1973

Thirty-three Mannich bases of 2,2'-methylene bis (3,4, 6-trichlorophenoxy-acetic acid) were synthesized hexachlorophene as potential antimicrobial agents and tested against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Trichophyton rubrum, Microsporum gypseum, Epidermophyton floccosum, Aspergillus niger and Aspergillus oryzae in vitro. It was found that: 1) 2,2'-Methylene bis [${\alpha}$-(3, 4, 6-trichlorophenoxy)-${\beta}$- (N,N -diethylamino) propionic acid] and 2,2'-methylene bis [${\alpha}$-(3,4,6-trichlorophenoxy)-${\beta}$-(N, N-dimethynlamo) propionoic acid] were active against Staphylococcus aureus and Bacillus subtilis at the concn. of 1 $\mu\textrm{g}$/$m\ell$ respectively; 2) 2,2'-Methylene bis [${\alpha}$-(3,4,6-trichlorophenoxy)-${\beta}$-(m-hydroxy-p-carboxyphenylamino) propionic acid] and 2,2'-methylene bis [${\alpha}$-(3, 4, 6-trichlorophenoxy)-${\beta}$-(cyclohexylamino) propionic acid] were active against Trichophyton-rubrum at the concn. of 2 $\mu\textrm{g}$/$m\ell$ respectively; 3) 2,2'-Methylene bis [${\alpha}$-3,4,6-trichlorophenoxy)-${\beta}$-(m-hydroxy-p-carboxyphenyl-amino) propionic acid] and 2,2'-methylene bis [${\alpha}$-(3,4,6-trcihlorophenoxy)-${\beta}$-(piperidino) propionic acid] were active against Microsporum gypseum at the concn. of 2 $\mu\textrm{g}$/$m\ell$ respectively; 4) 2,2'-Methylene bis [${\alpha}$-(3,4,6-trichlorophenoxy)-${\beta}$-(m-hydroxyphenylamino) propionic acid], 2,2'-methylene bis [${\alpha}$-(3, 4,6-trichlorophenoxy)-${\beta}$-(m-hydroxy-p-carboxy phenylamino) propionic acid], 2,2'-methylene bis [${\alpha}$-(3,4,6-trichlorophenoxy)-${\beta}$-(o-chlorophenylamino) propionic acid], 2,2'-methylene bis [${\alpha}$-(3,4,6-trichlorophenoxy)-${\beta}$-(o-chloro-p-nitrophenylamino) propionic acid], 2,2'-methylene bis [${\alpha}$- (3,4,6-trichlorophenoxy)-${\beta}$-(methylamino) propionic acid], 2,2'-methylene bis [${\alpha}$-(3,4,6-trichlorophenoxy)-${\beta}$-(hydroxylamino) propionic acid], 2,2'-methylene bis [${\alpha}$-(3,4,6-trichlorophenoxy)-${\beta}$-(cyclohexylamino) propionic acid], 2,2'-methylene bis [${\alpha}$-(3,4,6-trichlorphenoxy)-${\beta}$-(morpholino) propionic acid], 2,2'-methylene bis [${\alpha}$-(3,4,6-trichlorophenoxy)-${\beta}$-(p-sulfophenylamino) propionic acid] and 2,2'-methylene bis [${\alpha}$-(3,4,6-trichlorophenoxy)-${\beta}$-(4-sulfu-l-nayphthlamino) aoi!c rppioncd (were active against Epidermophyton floccosum at the concn. of 1 $\mu\textrm{g}$/$m\ell$ respectively; 5) 2,2'-Methlene bis [${\alpha}$-(3,4,6-trichlorophenoxy)-${\beta}$-(m-hydroxyphenylamino) propionic acid], 2,2'-methylene bis (a-(3,4,6-trichlorophenoxy)-${\beta}$-(m-hydroxy-p-carboxyphenylamino) propionic acid], 2,2'-methylene bis [${\alpha}$-(3,4,6-trichlorophenoxy)-${\beta}$-(p-methylphenylamino) propionic acid] and 2,2'-methylene bis [${\alpha}$-(3,4,6-trichlorophenoxy)-${\beta}$-(hydroxylamino) propionic acid] were active against Aspergillus niger and Aspergillus oryzae at the concn. of 1 $\mu\textrm{g}$/$m\ell$ respectively.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.273-281
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• 2012

This study was conducted for the establishment of the analytical method of pesticide residues in rice straw for 9 pesticides; etofenprox, tricyclazole, diazinon, edifenphos, propiconazole, carbaryl, carbofuran, 3-hydroxy carbofuran and 3-keto carbofuran and for the monitoring of these pesticides in rice straw for livestock feed in Korea. These pesticides were classified into 4 groups according to analytical instrument condition. Group 1 (HPLC-UVD1) included tricyclazole and etofenprox while group 2 (HPLC-UVD2) included propiconazole and edifenphos. Group 3 (HPLC-FLD) included carbaryl, carbofuran, 3-hydroxy carbofuran and 3-keto carbofuran. Group 4 (GC-NPD) included Diazinon. The dried rice straw samples were extracted with acetone and purified by liquid-liquid partition and solid phase extraction (SPE): Combination of Florisil SPE and amino-propyl SPE was used for group 1 and group 2, amino-propyl SPE for group 3, and Florisil SPE was for group 4. Recovery was in the ranged 70~110% and the limits of quantitation (LOQ) were lower than the half of maximum residue limits. Therefore this method was proved to be efficient for monitoring of these pesticides residue in rice straw. A total of 18 rice straw samples from 6 provinces in Korea in 2010 were analyzed using established method and, only 3-keto carbofuran was detected in one sample at concentration of 0.04 mg/kg.

• The Korean Journal of Pesticide Science
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• v.16 no.3
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• pp.236-241
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• 2012

The characteristics of chlorpyrifos was studied to clarify the effect of the cultivation season, spray intervals, spray volume and concentration on residues in chilli and sweet peppers cultivated under greenhouse condition. Residue levels of chlorpyrifos detected in chilli pepper fruit cultivated were 1.5 to 2.7 times higher in winter(February-March) than those in summer(June-July). During winter season residue levels of chlorpyrifos in chilli peppers were 6.9~3.2 times higher than those in sweet peppers for 10 days after 3 times application with 7 days interval. Residue levels in chilli pepper were from 2.070 mg/kg at 1 day to 0.929 mg/kg at 10 day, while those in sweet pepper were from 0.302 mg/kg to 0.291 mg/kg. Residue levels in sweet pepper to which are 3 times applied with 7 days interval were from 0.302 mg/kg at 1 day to 0.291 mg/kg at 7 day, and the residue levels in sweet pepper which are 3 times applied with 3 days interval were from 0.498 mg/kg at 1 day to 0.470 mg/kg at 7 day. Residue levels of chlorpyrifos in the sweet peppers applied by double concentration were 2.5 times higher than those sprayed by normal standard amounts diluted in double volume.

• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.121-130
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• 2012

In analyzing pesticide residue, LLE (liquid liquid extraction) is generally applied as one of the existing methods, but needed quite a lot of organic solvents and analytical apparatuses for the sample pre-treatment. In addition to its long analysis time and complex analytical processes, it is required to develop a more rapid and efficient method at present. In order to establish an economic and simple pesticide residue analytical method, this study carried out a comparative experiment on the existing analytical method with a new sample pre-treatment method named QuEChERS (quick, easy, cheap, effective, rugged and safe), which extracts and refines pesticide components by directly adding solid powder into the sample. Both the two analytical methods showed favorable values of correlation coefficient ($R^2$ > 0.99) of calibration curves. In terms of the detection limit (identification limit), imidacloprid showed 0.02 mg/kg, while the rest of pesticides showed a level around 0.05 mg/kg. The results of this experiment revealed that the recovery of LLE was 92.8-100.9% and the RSD was below 2.5%. On the other hand, the recovery of QuEChERS was 92.2-101.6% and RSD was below 1.9%. As a result of comparing the amount of pesticide residue by the time between the two analytical methods by using Paired t-Test, there was no significant difference between the two analytical methods as the p-value ranged from 0.3148-0.9890. Considering the results of the two methods, the QuEChERS method had similar recovery, compared to the analytical method using the existing LLE, and the analytical time was shortened by about one fourth of that of the existing method. Moreover, since it excludes the use of harmful organic solvents like dichloromethane during the process of extraction, thus leading to protecting experimenters health and remarkably reducing the amount of disused solvents, it is judged as an echo-friendly and economic analytical method.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.282-287
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• 2012

This study was carried out to clarify the effects of the application of pesticide by different spray nozzle types on pesticide residues. The average droplet size and discharge rate were investigated when the manual compressed sprayer with two head disk type nozzle and the knapsack engine powered sprayer with two head fan shape nozzles were used. The fan type nozzles were classified into three types by the number of orifice in the nozzle. Three type nozzles tested were fan with one orifice, fan with two orifices and fan with three orifices. Fan (trade name : D-3) with 2.4 L/min. of the discharge rate and $76{\mu}m$ of the average droplet size while maintaining constant pressure $1.1{\pm}0.2$ MPa, and fan D-35 with 2.6 L/min. and $90{\mu}m$ while maintaining constant pressure $1.0{\pm}0.2$ MPa were appropriate. The orifice size of D-3 was 0.65 mm length ${\times}$ 0.45 mm width and the orifice size of D-35 was 0.62 mm length ${\times}$ 0.46 mm width. The residue levels of imidacloprid on perilla leaves among four applications by four different nozzles show significantly difference with 5% significance level. The residue levels $3.76{\sim}3.92mg\;kg^{-1}$ by fan or disk type is smaller than $4.52{\sim}4.92mg\;kg^{-1}$ by fan II or fan III. The residue levels of imidacloprid on perilla leaf were different depend on the spray nozzles type.

• The Korean Journal of Pesticide Science
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• v.14 no.1
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• pp.10-15
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• 2010

Most pesticides are poorly soluble in water and must be dissolved in a solvent carrier before being added to the test medium on aquatic toxicity test. The concentration of solvent is critical to the success of a test. This study were conducted to recommend possible organic solvents which have good solubility for pesticides and low toxicity to Korean native water flea to establish new standard toxicity test methods using Korean native water flea for ecological risk assessment of pesticide. Four Korean freshwater cladocerans, Daphnia obtusa, Daphnia sp., Moina macrocopa and Simocephalus vetulus were exposed to 10 different organic solvents during 48 hours to evaluate their toxic response to solvents. Ethyl acetate was the most toxic to cladocerans tested. Although ethyl ether was the least toxic to cladocerans tested, it may not adequate as possible solvent in aquatic toxicity test due to high volatility and low water solubility. In conclusion, acetone, methanol, ethanol and acetonitrile which has low toxicity as well as good water solubility are recommended as optimal organic solvent to use in aquatic toxicity tests with Korean native cladocerans tested.

• Korean Journal of Poultry Science
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• v.38 no.1
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• pp.21-28
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• 2011

This study was conducted to investigate the effect of dietary supplement of Alisma canaliculatum and Viscum album on the growth performance and immune response of broiler chickens. One hundred and forty Ross broiler chicks (1 day old) were assigned to 4 treatments in 5 replications with 7 birds per replication. The dietary treatments were NC group (without antibiotics), PC group (basal + 50 ppm Oxytetracycline), AC group (basal + Alisma canaliculatum 0.5%), and VA group (basal + Viscum album 0.5%). The results revealed that body weight gain and feed intake were not significantly different among the treatments. Addition of AC to the diet showed significantly higher feed conversion ratios than the VA addition diet and other treatments (p<0.05). The concentration of linolenic acid, ${\alpha}$-linolenic acid and arachidonic acid in the AC and VA treatment were relatively higher than that in the antibiotic treatment, while there was no difference in the concentration of SFA, USFA, and USFA/SFA. The serum IgG concentration in chickens tended to increase in the AC and VA treatment groups compared to NC group. The IL2 concentration in AC and VA groups was significantly higher than in other group (p<0.05). IL6 was not detected, however. GOT, GPT, and T-billirubin in the VA group were significantly higher than in other groups (p<0.05). Thus, the VA additives can result in the damage of liver and kidney. In conclusion, the dietary supplement of a 0.5% of AC and VA showed a similar growth performance and increased immunity response comparable to supplementing a 50 ppm Oxytetracycline. Therefore, it can be said that the AC and VA are possible alternates of antibiotics.

• The Journal of Engineering Geology
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• v.21 no.2
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• pp.163-178
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• 2011

A test borehole was drilled in the Cheongwon area to investigate the relationship between geochemical environment and the natural occurrence of radioactive materials (uranium and Rn-222) in borehole groundwater. The borehole encountered mainly biotite schist and biotite granite, with minor porphyritic granite and basic dykes. Six groundwater samples were collected at different depths in the borehole using the double-packed system. The groundwater pH ranges from 5.66 to 8.34, and the chemical type of the groundwater is Ca-$HCO_3$. The contents of uranium and Rn-222 in the groundwater are 0.03-683 ppb and 1,290-7,600 pCi/L, respectively. The contents of uranium and thorium in the rocks within the borehole are 0.51-23.4 ppm and 0.89-62.6 ppm, respectively. Microscope observations of the rock core and analyses by electron probe microanalyzer (EPMA) show that most of the radioactive elements occur in the biotite schist, within accessory minerals such as monazite and limenite in biotite, and in feldspar and quartz. The high uranium content of groundwater at depths of -50 to -70 m is due to groundwater chemistry (weakly alkaline pH, an oxidizing environment, and high concentrations of bicarbonate). The origin of Rn-222 could be determined by analyzing noble gas isotopes (e.g., $^3He/^4He$ and $^4He/^{20}Ne$).