• The Korean Journal of Ecology
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• v.27 no.1
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• pp.43-47
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• 2004

This research was investigated to prepare basic data in a study on the copper tolerance of herbaceous plants through the growth rate and the elimination rate dependent on Cu concentration of 6 species; Commelina communis, Medicago sativa, Echinochloa frumentancea, Zea mays, Helianthus annuus and Abutilon avicennae, We examined the germination rate, root and shoot growth of seedling and fresh biomass of 6 species (Commelina communis, Medicago sativa, Echinochloa frumentancea, Zea mays, Helianthus annuus and Abutilon avicennae) painted to Cu contaminated soil (50, 100, 200, 300-CuCl₂/㎏) and control for 14 days. The germination rate of H. annuus, E. frumentancea and C. communis were not affected by Cu concentration. However, root and shoot growth of H. annuus was about 7% of control and the biomass was 35% of control at 300 ㎎-CuCl₂/㎏. E. frumentancea and C. communis that showed good growth rate at higher Cu contaminated soil (>200 -CuCl₂/㎏), were the most tolerant plant to Cu concentration. Especially, E. frumentancea eliminated over 30% of Cu in soil and the amount of Cu uptake increased with increasing Cu concentration; 1,020㎎ Cu per 1 ㎏ of soil at 300 ㎎-CuCl₂/㎏. From these results, we concluded that E. frumentancea would be used for phytoremediation.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2011.10a
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• pp.14-14
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• 2011

Polyamines (putrescine, spermidine and spermine) play pivotal roles in plant defense to different abiotic and biotic stresses. In order to understand the function of ginseng spermidine synthase gene, a key gene involved in biosynthesis of polyamines, transgenic plant was generated in Arabidopsis. The transgenic plants exhibited high levels of polyamines compared to the untransformed control plants. We investigated the tolerance capacity of transgenic plants to abiotic stresses such as salinity and copper stress. In addition, transgenic plants also showed increased resistance against one of the important fungal pathogens of ginseng, the wilt causing Fusarium oxysporum and one of important bacteria, bacterial blight causing Pseudomonas syringae. However, an activity of the polyamine catabolic enzyme, diamine oxidase (DAO) was increased significantly in F. oxysporum and P. syringae infected transgenic plant. Polyamine catabolic enzymes which may trigger the hypersensitive response (HR) by producing hydrogen peroxide ($H_2O_2$) seem act as an inducer of PR proteins, peroxidase and phenyl ammonium lyase activity. The transgenic plants also contained higher antioxidant enzyme activities, less MDA and $H_2O_2$ under salt and copper stress than the wild type, implying it suffered from less injury. These results strongly suggest an important role of spermidine as a signaling regulator in stress signaling pathways, leading to build-up of stress tolerance mechanisms.

• Korean Journal of Agricultural Science
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• v.7 no.1
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• pp.52-58
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• 1980

This study was conducted to detect copper which is considered in the soils of orchards, since copper fungicide has been applied to fruit trees. Soil samples taken from the fields of the chief producing districts of apple (Chungju, Yesan, Daegu), pear (Yangju, Bucheon, Seonghwan) and citrus (Seogypo in Jeju island) were analysed by an atomic absorption spectrophotometer. The results obtained were summarized as follows ; 1. In orchards of apple, the amount of copper of soils from Yesan, Chungju and Daegu were ranged 2.6-171.3ppm, 2.2-136.1ppm and 14.3-134.6ppm, respectively. Very little copper was detected from the soils in the field which has been cultivated for less than 20 years. About 100ppm and 130-170ppm of copper were detected in the field which has been cultivated for 30 years and for 50-60 years, respectively. Most of the copper was detected in the surface layer of soils (0-10cm), while very low content of copper was detected in the deeper layer of soils (10-20cm). 2. In orchards of pear, 20-30ppm of copper was detected from the surface of soils in the field which has been cultivated for more than 30 years and the highest level of copper, 36.8ppm, was detected from Yangju area. The amount of copper of soils from Yangju, Seonghwan and Bucheon were ranged 3.6-36.8ppm, 9.7-19.4ppm and 3.6-24.7ppm, respectively. 3. In orchards of citrus of Jeju island, only trace amount and 23-38ppm of copper were detected in the fields cultivated for 15 years and 20-30 years, respectively. The highest level of copper, 57ppm, was detected from the surface layer of soils in the field which has been cultivated for 35 years, but in most of the soil samples tested, only the natural background level of copper, about 20ppm, was detected. 4. The levels of copper residue in all the soil samples tested were lower than the tolerance level (125ppm of copper which is extracted in 0.1N-HCl solution), except those of copperr residue, 130-170ppm, that were detected from the orchards of apple which have been under cultivation for 50-60 years. Hence no problem for the farming could be speculated with the present concentration of copper analysed.

• Journal of Microbiology and Biotechnology
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• v.20 no.6
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• pp.974-977
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• 2010

Cyclophilins contain the conserved activity of cis-trans peptidyl-prolyl isomerase, which is implicated in protein folding, and function as molecular chaperones. When the yeast cyclophilin A gene (cpr1) was subcloned into the prokaryotic expression vector pKM260, it was found that the expression of Cpr1 drastically increased the cell viability of E. coli BL21 when under abiotic stress conditions, as in the presence of cadmium, copper, hydrogen peroxide, heat, and SDS. Therefore, this study illustrates the importance of Cpr1 as a molecular chaperone that can improve the cellular stress responses when E. coli cells are exposed to adverse conditions, while also demonstrating its potential to increase the stability of E. coli strains utilized for the production of recombinant proteins.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.26-27
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• 2006

The fundamental mechanical characteristics under tensile and bending deformations of hermetically-sealed reinforced Bi-2223 tape and CTOP processed Bi-2223 tape were examined at 77K. Also, the Tensile strain dependence of the critical current, $I_c$, was obtained at 77K and self-field. The reinforced hermetic tape showed higher tensile strength and a better Tensile strain tolerance than the CTOP processed tape. For bending tests, a rho-shaped sample holder was used giving multiple bending strains. in increasing order. In the same case under bending deformation, the hermetic tape showed a higher bending strain tolerance than the CTOP processed tape. This higher strength of the hermetic tape can be attributed to the thick hardened copper reinforcement layer.

• Korean Journal of Plant Resources
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• v.24 no.1
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• pp.48-54
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• 2011

This study was performed to analyze the possibility of using Korean native Aster koraiensis Nakai for phytoremediation at various fields. A. koraiensis was cultivated at paddy, upland and forest soils contaminated with heavy metals. After 8 weeks of cultivation, and growth and its absorbing capacity of heavy metals were analyzed. The results showed that A. koraiensis was grown well even at the soil highly contaminated with heavy metals, which means it has a tolerance to heavy metals. As analysis results of arsenic, cadmium, copper, lead and zinc contents absorbed from various soils contaminated with heavy metals, heavy metal absorbing capacity of A. koraiensis was depending on the heavy metal contents in the soils and soil property. In case of arsenic, cadmium and copper, heavy metal accumulation capacities of Aster koraiensis were much influenced by contents of heavy metals in the soils. Absorbing capacity of plants was increased when heavy metal contents in the soils were high. Lead absorbing capacity was depending more on soil property than lead contents in the soil, and was great at sandy soil of forest. Zinc absorbing capacity was influenced by both soil properties and Zn contents in the soil, was increased at paddy soil contaminated with high concentrations of heavy metals and upland soils. In general, A. koraiensis had a tolerance to heavy metals and showed great absorbing capability of heavy metals. So A. koraiensis can be used as a good landscape material for phytoremediation at various soils contaminated with heavy metals.

• Journal of the Korean Chemical Society
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• v.50 no.1
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• pp.23-31
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• 2006

carbon modified methods were used for the preconcentration and determination of copper in some real samples using the flame atomic absorption spectrometry. The copper ions was adsorbed quantitatively on the activated carbon due to their complexation with 4- amino-2, 3-dimethyl-1-phenyl-3-pyrazoline (ADMPP) or 4-(4- methoxybenzylidenimin) thiophenole (MBITP). The adsorbed copper on solid phase was eluted quantitatively using small amount of nitric acid. The influence of important parameters including pH, amount of carrier, flow rate, amount of activated carbon and type and concentration of eluting agent for obtaining maximum recovery were investigated. The methods based on ADMPP and MBITP at optimum conditions is linear over concentration range of 0.05-1.5 g mL-1 and 0.05-1.2 g mL-1 of copper with correlation coefficient of 0.9997 and 0.9994 and both detection limit of 1.4 ng mL-1, respectively. The preconcentration leads to enrichment factor of 310 and break through volume of 1550 mL for both ligands. The method has a good tolerance limit of interfering ion and a selectivity that has been successfully applied for the determination of copper content in real sample such as tap, spring, river and waste water.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1557-1567
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• 2012

Glutathione reductase (GR, E.C. 1.6.4.2) is an important enzyme that reduces glutathione disulfide (GSSG) to a sulfydryl form (GSH) in the presence of an NADPH-dependent system. This is a critical antioxidant mechanism. Owing to the significance of GR, this enzyme has been examined in a number of animals, plants, and microbes. We performed a study to evaluate the molecular properties of GR (OsGR) from rice (Oryza sativa). To determine whether heterologous expression of OsGR can reduce the deleterious effects of unfavorable abiotic conditions, we constructed a transgenic Saccharomyces cerevisiae strain expressing the GR gene cloned into the yeast expression vector p426GPD. OsGR expression was confirmed by a semiquantitative reverse transcriptase polymerase chain reaction (semiquantitative RT-PCR) assay, Western-blotting, and a test for enzyme activity. OsGR expression increased the ability of the yeast cells to adapt and recover from $H_2O_2$-induced oxidative stress and various stimuli including heat shock and exposure to menadione, heavy metals (iron, zinc, copper, and cadmium), sodium dodecyl sulfate (SDS), ethanol, and sulfuric acid. However, augmented OsGR expression did not affect the yeast fermentation capacity owing to reduction of OsGR by multiple factors produced during the fermentation process. These results suggest that ectopic OsGR expression conferred acquired tolerance by improving cellular homeostasis and resistance against different stresses in the genetically modified yeast strain, but did not affect fermentation ability.

• Plant Biotechnology Reports
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• v.5 no.4
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• pp.323-329
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• 2011

MuSI, a gene that corresponds to a domain that contains the rubber elongation factor (REF), is highly homologous to many stress-related proteins in plants. Since MuSI is up-regulated in the roots of plants treated with cadmium or copper, the involvement of MuSI in cadmium tolerance was investigated in this study. Escherichia coli cells overexpressing MuSI were more resistant to Cd than wild-type cells transfected with vector alone. MuSI transgenic plants were also more resistant to Cd. MuSI transgenic tobacco plants absorbed less Cd than wild-type plants. Cd translocation from roots to shoots was reduced in the transgenic plants, thereby avoiding Cd toxicity. The number of short trichomes in the leaves of wild-type tobacco plants was increased by Cd treatment, while this was unchanged in MuSI transgenic tobacco. These results suggest that MuSI transgenic tobacco plants have enhanced tolerance to Cd via reduced Cd uptake and/or increased Cd immobilization in the roots, resulting in less Cd translocation to the shoots.

• Mycobiology
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• v.51 no.6
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• pp.379-387
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• 2023

In this study, twenty-five yeast strains were isolated from soil samples collected in the gold mining ore in Gia Lai, Vietnam. Among them, one isolate named GL1^T could highly tolerate Cu²⁺ up to 10 mM, and the isolates could also grow in a wide range of pH (3-7), and temperature (10-40 ℃). Dried biomass of GL1 was able to remove Cu²⁺ effectively up to 90.49% with a maximal biosorption capacity of 18.1 mg/g at pH 6, temperature 30 ℃, and incubation time 60 min. Sequence analysis of rDNA indicated this strain was closely related to Rhodotorula mucilaginosa but with 1.53 and 3.46% nucleotide differences in the D1/D2 domain of the 28S rRNA gene and the ITS1-5.8S rRNA gene-ITS2 region sequence, respectively. Based on phylogenetic tree analysis and the biochemical characteristics, the strain appears to be a novel Rhodotorula species, and the name Rhodotorula aurum sp. nov. is proposed. This study provides us with more information about heavy metal-tolerant yeasts and it may produce a new tool for environmental control and metal recovery operations.