• Korean Journal of Environmental Agriculture
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• v.15 no.3
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• pp.306-315
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• 1996

This study was performed to develop the biological treatment technology of wastewater polluted with heavy metals. The lead-tolerant microorganism, Pseudomonas aeruginosa which possessed the ability to accumulate lead, was isolated from the industrial wastewater polluted with various heavy metals. The characteristics of lead accumulation in the cells and the recovery of the lead there from were investigated. Removal rate of lead from the solution containing 100mg/l of lead by the lead-tolerant microorganism was more than 97% at 48 hours after inoculation with the microorganism. A large number of the electron-dense granules were found mainly on the cell wall and cell membrane fractions, when determined by transmission electron microscopy. Energy dispersive X-ray spectroscopy revealed that the electron-dense granules were lead complex with the substances binding heavy metals. The lead accumulated into cells was not desorbed by distilled water, but more than 87% of the lead accumulated was desorbed by 0.1M-EDTA. The residues of the cells after combustion at $550^{\circ}C$ amounted to about 30% of the dry weight of the cells. EDS analysis showed that the residues were relatively pure lead compounds containing more than 86% of lead.

• Korean Journal of Microbiology
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• v.24 no.1
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• pp.24-31
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• 1986

The optimal conditions for the formation and the regeneration of Pseudomonas spheroplast were measured. Pseudomonas spp. cells were transformed to spheroplasts from 99.0% to 99.9% by treatment of $100{\mu}g/ml$ lysozyme and 10mM EDTA at room temperature. The optimal pH for the spheroplast formation was pH 8.0. Magnecium chloride, calcium chloride and streptomycin were effective on the stabilization of Pseudomonas spheroplast, while $Mg^+\;and\;Na^+$ ions were effective on the formation of Pseudonomas spheroplast. Rich Regeneration Medium was used for the regeneration of Pseudonomas spheroplast. To improve regeneration frequency, Bovin Serum Albumine and cationic ions were added to the spheroplast dilution beffer and regeneration environment respectively. Treatment of 20mM calcium chloride in ehr Rich Regeneration Medium could improve the yield of regenerants as much as 28-fold. Treatment of 1% Bovin Serum Albumine in the spgeroplast formation and dilution buffer increased the yield of regenerants to 10-fold. Also, the regeneration frequency was improved to 14-fold shen Rich Regeneration Meidum containing 0.5% Gelatin was used for regeneration as well as 1% Bovin Serum Albumine.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.486-489
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• 2011

In the present work, diazinon which is known as nondegradable and environmental toxic material was efficiently treated by the cell surface-displayed organophosphorus hydrolase (OPH) biocatalyst. The culture temperature of $25^{\circ}C$ culture temperature and the addition of 0.2 mM ethylenediamine tetraacetate (EDTA) were effective conditions for the production of recombinant OPH in Escherichia coli. 25 and 50 ppm diazinon were treated with removal rate of 4.5 and $7.2mg/g{\cdot}min$, respectively and with all over 90% removal efficiencies using recombinant cell lysates through ultrasonication disruption process. Thus, these experimental results could be utilized in environmental friendly biological treatment system for toxic chemicals such as diazinon.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1236-1241
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• 2007

The feasibility of soil washing was investigated in the laboratory to treat heavy metals-contaminated railway soil. Various organic acids including ethylene diamine tetraacetic acid (EDTA) and citric acid as well as inorganic acids such as hydrochloric acid (HCl) and phosphoric acid were tested to evaluate washing efficiency. Generally, inorganic acid showed higher removal efficiency compared to organic acids. Specially, EDTA, which are well known as most effective washing agent to remove heavy metals from soil, was not efficient to remove heavy metals in this study. Among washing agents tested in this study, HCl was most effective. The removal of Cd, Cu, and Pb was high, however, that for Zn and Ni was less than 30% with 0.5 M HCl. This difference comes from analytical methods (Korean Standard Test Method for Soil). Aqua regia was used to extract Zn and Ni, however 0.1 N HCl was used for other metals. As a result, simple washing technology is not effective, to treat railway contaminated soil with heavy metals.

• Korean Journal of Microbiology
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• v.38 no.4
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• pp.281-286
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• 2002

Detection of Vibrio vulnificus in fish farm and searching for the bactericidal methods on this bacteria were studied. To detect this microorganism in sea water, mud, fish and mussels, selective isolation methods and detection of vvhA gene were used from January to October,2000. V. vulnificus was detected from May when the water temperature was over $17^{\circ}C$. From June to September, higher than $19^{\circ}C$, this bacteria could be isolated from most of the samples. Freezing and refrigerating did not inhibit the growth of V. vulnificus. Citric acid did not show the bactericidal effect, but more than 500 mg/l of EDTA did. With the aid of UV and photocatalyst, $TiO_{2}$ showed bactericidal effect after 15 minute treatment. Photocatalytic system consisted of glass bead coated with $TiO_{2}$ and UV illumination showed bactericidal effect on V. vulnificus at the turnover rate of 0.2/min.

• Restorative Dentistry and Endodontics
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• v.17 no.1
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• pp.36-54
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• 1992

The purpose of this study was to compare the shear bond strengths to ground dentin surfaces of four dentinal bonding agents in 193 teeth. Various dentin surfaces treated with four dentin bonding agents were attached with two restorative composite resins. The effectiveness of the bonding were tested by the monitoring the shear bond strength. The shear bond strengths were measured after 2 hours and 24 hours after surface conditioning with four dentin bonding agents. Effects of EDTA, the additive illumination, and sealer treatments without primer on bond strength to dentin surfaces were assessed. In addition the effects of the thickness of specimens ranging from 0.65 mm to 1.95 mm and the ratio of catalyst and base paste on the bond strength of chemical cure composite resin were estimated. The shear bond strength was determined by testing specimens in the Instron universal testing machine (Model No. 1122) at a crosshead speed of 1.0 mm/min. Following condusions were drawn: 1. The highest mean shear bond strengths of chemical cure composite resin to dentin conditioning with dentin bonding agents aged 2 hours were obtained, and then that was decreased with time followed by EDTA treatment. 2. In light cure composite resin, the shear bond strength was increased following dentin conditioning with bonding agents with time, irradiation time and EDTA treatment except in SB group. 3. The thicker the composite resin specimen was, the less the shear bond strength in chemical cure composite resin was. 4. In light cure composite resin, there was a little change in shear bond strength following dentin conditioning with bonding agents. 5. In chemical cure composite resin, the shear bond strength was the highest in the ratio of 1/1 of catalyst and base part. 6. Without a dentin primer, shear bond strength to dentin conditioned only with UB sealer was the highest among four sealers in light cure composite resin.

• Korean Journal of Environmental Agriculture
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• v.21 no.2
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• pp.122-129
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• 2002

The removal rate of heavy metals from the wastewater, the accumulation and translocation of heavy metals in plants after transplanting, and the responses of water celery growth with different wastewater treatments were investigated to determine the potential ability of green-remediation with hydroponic culture of water celery. The removal rate and translocation of Cd, Cu, Ni and Pb from different wastewater to plants were compared with cultivation periods after transplanting. The removal rate of heavy metals from wastewater was different with each treatment but increased with growing periods of water celery plants. The removal rate of Cd, Cu, Ni and Pb in Artificial solution, Artificial solution+EDTA, Munmark industrical wastewater, Jungsun minewater is ranged from 22 to 73%, from 28 to 100%, from 13 to 92% and from 41 to 100% at 6 days after transplanting, respectively. The translocations of Cd, Cu, Ni and Pb from roots to shoots in Artificial solution, Artificial solution+EDTA, Munmark industrical wastewater, Jungsun minewater are ranged from 14 to 28%. 8 to 30%. from 28 to 45% and from 2 to 15% at 12 days after transplanting, respectively. In plant growth responses, it appears to be inhibited the plant growth over all treatments excepts for Munmark industrial wastewater in these glowing periods. Therefore the water celery might play a useful role in phytoremediation to clean up wastewater contaminated with Cd, Cu, Ni or Pb.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.42-42
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• 2002

본 연구는 한국 재래산양의 핵이식에 있어서 공여핵은 귀세포를, 수핵난자는 소 및 돼지의 난포란을 이용하여 핵이식을 실시하여 복제수정란의 체외발달율과 이종간의 핵이식 가능성을 검토하였다. 공여핵은 재래산양의 귀세포를 채취하여 10% FBS 가 첨가된 TCM-199 배양액으로 체외 배양을 실시하여 monolayar Confluent 형성후 0.25% Trypsin-EDTA을 처리하여 계대배양을 실시하였다. (중략)

• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.243-250
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• 2015

A bone marrow biopsy that has undergone decalcification with 10% nitric acid could not be used for various pathological tests and had extremely limited reproducibility. The fixing solution of each experimental group was differentiated in usage, one solution including acid and the other not. The use of the decalcification solution was separated into either acidic or alkaline (EDTA), and further experiments were conducted with differing time phases. When using a fixing solution and decalcification solution which included acid, the specimens were faulty to the extent that all pathological tests were impossible. However specimens that were processed with an EDTA type decalcification solution did not display a non-specific reaction in EBV ISH and were even able to produce results that were at a level suited to various studies or a pathological diagnosis in the FISH, DNA, RNA tests. By improving the fixing and decalcification of bone marrow biopsy, the study was able to make possible ISH, FISH, DNA tests as well as RNA study, and secured the sensitivity, specificity, and reproducibility of various test methods. The stabilization of various test methods that use bone marrow biopsy contributes to the diagnosis, prognosis, prediction, treatment of the patient and provide guidelines for decision-making.

• Applied Biological Chemistry
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• v.27 no.3
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• pp.174-179
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• 1984

Some physico-chemical properties of proteolytic enzyme produced from Streptomyces alboniger Hesseltine were characterized. The optimal pH and temperature of the enzyme were around pH 9.0 and $40^{\circ}C$, respectively. The enzyme was stable between pH $6.0{\sim}10.8$ and the enzyme activity was not inactivated by heat treatment in lower temperature than $40^{\circ}C$. However the enzyme activity decreased by 70% of the initial activity for 10minutes at $70^{\circ}C$. The Km value was $7.1{\mu}M$ with Hammarsten casein and $333.3{\mu}M$ with cytochrom C. The activity of enzyme was inhibited by metal ions in the order of $Fe^{+++}>Hg^{++}>Cu^{++}>Pb^{++}>Zn^{++}$, whereas $Ca^{++}$ increased the enzyme activity. There was no effect of $Mg^{++}$ and $Co^{++}$ on the enzyme activity. The enzyme was inhibited by EDTA strongly. When $Ca^{++}$ was added to the EDTA-denaturated enzyme, the activity of enzyme was restored.