• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.142-148
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• 1997

This study was performed to develop the biological treatment technology of wastewater polluted with heavy metals. Heavy metal-tolerant microorganisms, such as Pseudomonas putida, P. aeruginosa, P. chlororaphis and P. stutzeri possessing the ability to accumulate cadmium, lead, zinc and copper, respectively, were isolated from industrial wastewaters and mine wastewaters polluted with various heavy metals. The effect of competing ions and metabolic inhibitors on heavy metal accumulation in the cells was investigated. Heavy metal accumulation into cells was drastically decreased in the presence of competing cation, $Al^{3+}$, and also decreased, at a lesser extent, in the presence of competing anions, $CO_3\;^{2-}$ and $PO_4\;^{2-}$. But heavy metal accumulation was not influenced generally in the presence of the other rations and anions. The accumulation of Cd, Zn or Cu by Cd-, Zn- or Cu-tolerant microorganism was remarkably decreased in the presence of metabolic inhibitors, but the accumulation of Pb by Pb-tolerant microorganism was little affected in the presence of metabolic inhibitors. These results suggested that the accumulation of Cd, Zn or Cu by Cd-, Zn- or Cu-tolerant microorganism was concerned with the biological activity depending on energy, and the accumulation of Pb by Pb-tolerant microorganism depended on not the biological activity but the physical adsorption on the cell surface. Each heavy metal-tolerant microorganism also exhibited some ability to accumulate the other heavy metals in solution containing equal concentrations of cadmium, lead, zinc and copper, when measured at 48 hours after inoculation of the microorganisms, but the accumulation rates were somewhat low as compared to the accumulation rates of heavy metal fitting to each tolerance. These results suggested that the accumulation of each heavy metal by each heavy metal-tolerant microorganism was a selective accumulation process.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.124-129
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• 1997

This study was performed to develop the biological treatment technology of wastewater polluted with heavy metals. Heavy metal-tolerant microorganisms, such as Pseudomonas putida, P. aeruginosa, P. chlororaphis and P. stutzeri possessing the ability to accumulate cadmium, lead, zinc and copper, respectively, were isolated from industrial wastewater and mine wastewater polluted with various heavy metals. The effect of several external factors, such as temperature, pH and heavy metal compounds on heavy metal accumulation in the cells was investigated. The amount of heavy metal accumulation into cells according to the kind of heavy metal compound was slightly increased in the case of the heavy metal compound with -nitrate group, but generally, there is little change according to the kind of compound in the amount of heavy metal accumulation. The amount of heavy metal accumulation according to the precultured time was increased in the case of the cell precultured for 24 hours, but generally the precultured time did not affect to the amount of heavy metal accumulation. Heavy metal accumulation into cells was affected by several external factors, such as temperature and pH. The optimum temperature and optimum pH of the accumulation of heavy metal into cells were $20{\sim}37^{\circ}C$ and pH $6{\sim}8$, respectively. By increasing the concentration of each heavy metal-tolerant microorganism in the solution, the total amount of heavy metal accumulated was increased, whereas the amount of heavy metal accumulated per cell(mg, heavy metal/g, dry cells) was decreased. These results indicated that the amount of heavy metal accumulated was not proportional to the concentration of microorganisms.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.327-332
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• 2019

Today's scientists try to remove heavy metals with many new technologies such as phytoremediation. One of the best cutting edge technologies is developing transgenic plants to remove certain heavy metal in soil. I constructed the transformation vector expressing T. goesingense Metal Transport Protein1 gene and TgMTP1: GFP genes. The transgenic plants were selected and confirmed the transformed genes into Arabidopsis thaliana genome. Expression was confirmed in several parts in Arabidopsis cells, tissues and organs. When TgMTP1 overexpressing Arabidopsis thaliana were subjected, transgenic plants showed higher heavy metal tolerance than non-transgenic. For further study I selected the transgenic plant lines with enhanced tolerance against four different heavy metals; Zn, Ni, Co, Cd. The accumulation of these metals in these plants was further analyzed. The TgMTP1 overexpressing Arabidopsis thaliana plant of selected lines are resistant against heavy metals. This plant is characterized by the expression of the MTP1 gene accumulating heavy metal in the vacuole and being simultaneously expressed on the plasma membrane. In conclusion, these plants may be used in plant purification applications, and as a plant with increased tolerance.

• Korean Journal of Environmental Agriculture
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• v.16 no.1
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• pp.55-60
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• 1997

Heavy metal-tolerant microorganisms, such as Pseudomonas putida, P. aeruginosa, P. chlororaphis and P. stutzeri which possessed the ability to accumulate cadmium, lead, zinc and copper, respectively, were isolated from industrial wastewaters and mine wastewaters polluted with various heavy metals. The distribution of heavy metal in the cell components, and amino acid compositions, was investigated. The distribution of heavy metal in the cell fractions of each heavy metal-tolerant microorganism grown for 20 hours in the basal medium containing 100mg/l of each heavy metal was investigated. In the case of cadmium-tolerant P. putida, lead-tolerant P. aeruginosa and copper-tolerant P. stutzeri, approximately $50{\sim}60%,\;30{\sim}40%$ and $10{\sim}17%$ of each heavy metal absorbed were distributed to cell wall, cell membrane and cytoplasm fractions, respectively. In the case of zinc-tolerant P. chlororaphis, approximately 32%, 55% and 13% of zinc were distributed to cell wall, cell membrane and cytoplasm fractions, respectively. These results indicated that the cell wall was a major adsorbing fraction of cadmium, lead and copper, and the cell membrane was that of zinc. Total amino acid content per gram of the cell grown in the culture media with heavy metal was higher than that of the cell grown in the culture media without heavy metal, and the content of acidic amino acids, such as aspartic acid(Asp.+Asn.) and glutamic acid(Glu.+Gln.) was higher than that of basic amino acids, such as histidine, lysine and arginine.

• Korean Journal of Environmental Agriculture
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• v.24 no.4
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• pp.379-385
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• 2005

This study was conducted to find out a useful bioremediation technology for heavy metal contaminated soil and water. We isolated strain CPB from heavy metal contaminated soil and evaluated the tolerance level and adsorption capacity of strain CPB to heavy metals (Strain is not determined yet). Strain CPB showed variable tolerance limit to different kinds heavy metal or concentrations of heavy metals. The growth of strain CPB was significantly inhibited by mixed heavy metals (Cd+Cu+Pb+Zn) than that of by single heavy metal. Strain CPB showed high binding capacity with Pb (Pb>Cd>Cu>Zn). In general, strain CPB showed high uptake of heavy metals such as Pb, Cd and Cu. It was observed that the capacity of heavy metal uptake from mixture of heavy metals was reduced in comparison with single heavy metal treatment. But total contents of heavy metal bound with cell in mixed heavy metal showed higher than in single heavy metal treatment. Heavy metal adsorption in cells was affected by several external factors, such as temperature and pH etc.. The optimum temperature and pH of the adsorption of heavy metal into cells were ca. $25{\sim}35^{\circ}C$ and pH ca. $5{\sim}7$, respectively. A large number of the electron dense particles were found mainly on the cell wall and cell membrane fractions, which was determined by transmission electron microscope. Energy dispersive X-ray spectroscopy revealed that the electron dense particles were the heavy metal complexes the substances binding with heavy metals.

• Korean Journal of Environmental Biology
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• v.17 no.4
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• pp.415-420
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• 1999

A biochemical oxygen demand (BOD) sensor loaded with Candida sp. was designed and constructed for the quick measurement of the concentrations of biologically assimilable organic substances dissolved in water. The sensitivity of the sensor was higher for glucose, acetic acid, aspartic acid and glutamic acid than that for lactose, sucrose and lactic acid. The sensitivities of BOD sensors loaded with $Zn^{2+}$ tolerant and intact strains were almost identical while the sensitivity of sensor loaded with Cd$^{2+}$ tolerant strain was considerably lower. The sensitivities of the sensors loaded with intact or $Zn^{2+}$ tolerant strains did not change with the concentration of $Cd^{2+}$ in the aqueous solution while the sensitivity of the sensor loaded with $Cd^{2+}$ tolerant strain decreased slightly. The sensitivities of the sensors loaded with intact strain, $Zn^{2+}$ or $Cd^{2+}$ tolerant strains were not affected by the concentration of $Zn^{2+}$ in the aqueous solution.n.

• Microbiology and Biotechnology Letters
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• v.49 no.3
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• pp.413-424
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• 2021

In order to enhance rhizoremediation performance, which remediates contaminated soils using the interactions between plants and microorganisms in rhizosphere, it is required to develop effective microbial resources that simultaneously degrade contaminants and promote plant growth. In this study, heavy metal-resistant rhizobacteria, which had been cultivated in soils contaminated with heavy metals (copper, cadmium, and lead) and diesel were isolated from rhizospheres of maize and tall fescue. After that, the isolates were qualitatively evaluated for plant growth promoting (PGP) activities, heavy metal tolerance, and diesel degradability. As a result, six strains with heavy metal tolerance, PGP activities, and diesel degradability were isolated. Strains CuM5 and CdM2 were isolated from the rhizosphere soils of maize, and were identified as belonging to the genus Cupriavidus. From the rhizosphere soils of tall fescue, strains CuT6, CdT2, CdT5, and PbT3 were isolated and were identified as Fulvimonas soli, Cupriavidus sp., Novosphingobium sp., and Bacillus sp., respectively. Cupriavidus sp. CuM5 and CdM2 showed a low heavy metal tolerance and diesel degradability, but exhibited an excellent PGP ability. Among the six isolates, Cupriavidus sp. CdT2 and Bacillus sp. PbT3 showed the best diesel degradability. Additionally, Bacillus sp. PbT3 also exhibited excellent heavy metal tolerance and PGP abilities. These results indicate that the isolates can be used as promising microbial resources to promote plant growth and restore soils with contaminated heavy metals and diesel.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.311-319
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• 1997

Heavy metal-tolerant microorganisms, such as Pseudomonas putida, P. aeruginosa, P. chlororaphis and P. stutzeri which possessed the ability to accumulate cadmium, lead, zinc and copper, respectively, were isolated from industrial wastewaters and mine wasewaters polluted with various heavy metals. Metal binding sites in the cells were investigated by extracting the components of the cells through pretreatments with hot water, acid, alkli, chloroform-methanol or chloroform-methanol/concentrated alkali. The heavy metal accumulation was drastically decreased by pretreatment with alkali or chloroform-methanol/concentrated alkali, but the heavy metal accumulation was not changed by pretreatment with chloroform-methanol. The amount of heavy metal accumulation was remarkably decreased by decreasing crude protein remaining in the cell. These results suggested that proteins of cell components played an important role on the heavy metal accumulation.

• Microbiology and Biotechnology Letters
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• v.7 no.4
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• pp.183-190
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• 1979

Cadmium ion-tolerant microorganisms were isolated from the sludge and soil of a cadmium ion-polluted area, a zinc mineralized area, in Kyung Sang Pook Do, Korea. A strain, C-7, which showed tile highest tolerance to cadmium ion was selected by screening from 18 cadmium tolerant microorganisms. By the taxonomical characteristics of this strain, it was identified as a variant of Erwinia sp.. The strain grew in a medium cadmium ion up to a concentration of 2, 800 $\mu\textrm{g}$/ml and the maximum intercellular accumulation of Cd$^{2+}$ was measured to be 28.60 mg/g dried cells (57.2％) during incubation in medium containing 50 $\mu\textrm{g}$/ml under aerobic condition at 28$^{\circ}C$ for 24 hour.r.

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.373-378
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• 2019

In the marine area, the salt concentration in the soil increases, and the inland heavy metal pollution increases the damage of plants. In the inland industrial development area, researches on the genetic resources of plants together with the heavy metal accumulation of Co, Ni, Zn, and so on are required. Both of these problems have caused scientists to work hard to find plants that are likely to cause stress in plant roots. In this study, seeds of Arabis stelleri var. japonica collected near the shore were used for germination. The growth and development and tolerance of both Arabis and Arabidopsis seeds were investigated under laboratory culture conditions. As a result, Arabis showed resistance about 3 times in 250 mM nickle and cobalt, and more than 4 times in 1 mM zinc when compared to Arabidopsis. The tolerance of Arabis to Na salts increased by 20% or more at 50 mM concentration and Arabis was resistant to heavy metals and salt concentration. The accumulation of Na ions in the body was measured as a preparation for studying the intracellular mechanism. As a result, it showed a further decrease in resistance to ground water roots. It is considered that the activity of the exporting gene is important rather than the mechanism of accumulation.