• 환경생물
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• 제22권3호
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• pp.394-399
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• 2004

S. marcescens LSY4가 충전된 BOD센서를 제작하여 표준오염물질을 포함한 수용액의 BOD를 측정하였다. 배양시간이 9∼16시간일 때에는 배양시간에 따른 BOD센서의 감응도에 큰 차이를 나타내지 않았으며, 균체량도 0.22~0.75mg $cm^{-2}$의 범위에서는 거의 동일한 센서의 감응도를 나타내었다. 수용액의 pH가 4~9사이로 변화할 경우 센서의 감응도가 가역적으로 변화하였으나 수용액이 더 산성이거나 더 염기성이 되면 센서의 감응도가 비가역적으로 저하되었다. 수용액에 중금속이온이 첨가되면 센서의 감응도가 감소하였으며, $Zn^{2+}$나 $Cd^{2+}$보다 $Cu^{2+}$혹은 $Ag^+$가 첨가되었을 때 센서의 감응도가 더 급격히 감소하였다. 중금속에 대한 내성이 유도된 균체를 충전하였을 때 중금속이온의 첨가에 따른 센서의 감응도 감소가 크게 완화되었으며, 이런 효과는 $Cd^{2+}$내성주보다 $Cu^{2+}$내성주에서 더 현저하였다.

• 한국환경과학회지
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• 제13권8호
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• pp.711-719
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• 2004

The effect of nickel (Ni) on growth and some tolerance strategies with regard to heavy metal tolerance mechanism was investigated in radish (Raphanus sativus) seedlings. The protective effect of histidine on nickel stress conditions was also monitored. The seedling growth decreased with an increase in metal concentrations. The inhibitory effect was more pronounced in the root elongation than in the shoot elongation. Increasing Ni supply showed a progressive increase of Ni concentrations in the roots and shoots. Ni content was higher in the shoots than in the roots. In the presence of nickel, radish exhibited an antioxidative defense mechanism, as evidenced by the elevated malondialdehyde(MDA), showing that nickel is an efficient inducer of lipid peroxidation. Exposure of radish to elevated concentrations of nickel was accompanied by an increase in the proline content. Supplemental histidine in the presence of Ni ameliorated metal-induced growth inhibition and lipid peroxidation. Combinations of Ni and histidine resulted in a significant decline in proline content compared with Ni stress alone, indicating that histidine may provide protection against the adverse effect of Ni stress. From the results it is suggested that histidine is an efficient chelator by complexing metal ion within the plant and may playa role in nickel tolerance implicated in metal detoxification.

• 한국환경농학회지
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• 제16권2호
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• pp.142-148
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• 1997

중금속오염폐수처리에의 미생물 이용 가능성을 검토하기 위하여 중금속에 강한 내성을 지님과 동시에 균체내 중금속 축적능력이 우수한 중금속 내성균을 분리하여 competing ion, 대사저해제 등과 같은 외부 요인에 따른 균체내 중금속 축적변화를 조사한 결과는 다음과 같다. 중금속을 처리한 용액중 양이온인 $Al^{3+}$이온과 음이온인 $CO_3\;^{2-}$ 및 $PO_4\;^{2-}$이온이 competing ion으로 존재할 경우 중금속 내성균의 균체내 중금속 축적은 크게 감소되었으나, 그외 다른 양이온들과 음이온들에 대해서는 거의 영향을 받지 않았다. Cd, Zn 및 Cu 내성균주의 Cd, Zn 및 Cu 축적은 대사저해제에 의하여 크게 감소되었으나, Pb 내성균주에 의한 Pb 축적은 거의 영향을 받지 않는 것으로 나타나 Cd, Zn 및 Cu 내성균주의 Cd, Zn 및 Cu 축적은 에너지 의존적인 과정으로서 물질대사와 관련되어 있는 것으로 생각되었으며, Pb 내성균주의 Pb 축적은 에너지 비의존적인 과정으로서 물질대사와 관련이 별로 없는 물리적인 과정에 의하여 축적되는 것으로 생각되었다. 각 중금속 내성균주들은 해당 중금속 축적능력에 비하여 낮았으나 타 중금속들의 축적능력도 있었으며, 여러가지 중금속들을 동일 농도로 복합처리 하였을 경우 해당 중금속들의 축적능력이 타 중금속들에 비하여 매우 높게 나타나 각 중금속 내성균주들의 해당 중금속 축적은 선택적인 과정에 의하여 축적되는 것으로 생각되었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권4호
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• pp.9-18
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• 2012

This study was carried out to leach valuable metal ions from the mine waste ore using the adapted indigenous bacteria. In order to tolerance the heavy metals, the indigenous bacteria were repeatedly subcultured in the adaptation-medium containing $CuSO_4{\cdot}5H_2O$ for 3 weeks and 6 weeks, respectively. As the adaptation experiment processed, the pH was rapidly decrease in the adaptation-medium of 6 weeks more than the 3 weeks. The result of bioleaching with the adapted bacteria for 42 days, the pH value of leaching-medium in the 3 weeks tend to increased, whereas the pH of the 6 weeks decreased. In decreasing the pH value in the adaptation-medium and in the leaching-medium, it was identified that the indigenous bacteria were adapted $Cu^{2+}$ the ion and the mine waste ores. The contents of Cu, Fe and Zn in the leaching solution were usually higher leached in 6 weeks than 3 weeks due to the adaptation. Considering the bioleaching rates of Cu, Fe and Zn from these leaching solutions, the highest increasing the efficiency metal ion were found to be Fe. Accordingly, it is expected that the more valuable element ions can be leached out from the any mine waste, if the adapted bacteria with heavy metals will apply in future bioleaching experiments.

• Journal of Microbiology and Biotechnology
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• 제33권7호
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• pp.895-908
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• 2023

Disposal of waste containing heavy metals into the environment is a major threat to human health and can result in toxic or chronic poisoning in aquatic life. In the current study, metal-resistant Raoultella ornithinolytica was isolated from metal-contaminated samples collected from the Tanjaro River, located southwest of Sulaymaniyah, Iraq. R. ornithinolytica was identified by partial amplification of 16S rRNA. The uptake potency of heavy metals was assessed using inductively coupled plasma-optical emission spectroscopy (ICP-OES) and indicated that R. ornithinolytica removed 67, 89, 63.4, 55.6, 56.5, 65, and 61.9% of Cd, Pb, Cr, Ni, Zn, Co, and Fe, respectively. These removal rates were influenced by temperature, pH, and contact time; at 35℃ and pH 5 with a change in the incubation time, the reduction rate improved from 89 to 95% for Pb, from 36.4 to 45% for Cu, and from 55.6 to 64% for Ni. Gene analysis indicated that R. ornithinolytica contained pbrT, chrB, nccA, iroN, and czcA genes, but the pcoD gene was absent. Energy-dispersive X-ray spectroscopy (EDS) images showed evidence of metal ion binding on the cell wall surface with different rates of binding. Transmission electron microscopy (TEM) detected different mechanisms for metal particle localization; cell surface adsorption was the main mechanism for Pb, Zn, and Co uptake, while Cd, Ni, and Fe were accumulated inside the cell. The current study describes, for the first time, the isolation of R. ornithinolytica from metal-contaminated water, which can be used as an eco-friendly biological expedient for the remediation and detoxification of metals from contaminated environments.

• 한국미생물·생명공학회지
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• 제7권4호
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• pp.183-190
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• 1979

아연 광산 지역의 오이와 토양으로 부터 cadmium 내성균의 분리를 시도하여 강도 cadmium 내성균인 17 균주를 순수 분리했다. 강도 cadmium 내성균인 C-7 균주에 대하여 미생물학적 성질과 세포내의 cadmium 축적에 대하여 검토했다. 본 내성균, C-7은 Erwinia sp. 고정되었으며 2,800ppm의 cadmium에 내성을 나타내는 고도 cadmium 내성균이었다. 본내성균은 cadmium 100 ppm의 농도에 무첨가시의 생육과 거의 같은 증식을 나타냈으나500ppm 이상의 농도에서는 유도기가 연장되며 1,000 ppm 이상의 농도에서는 증식이 조지되었다. 본 내성균은 cadmium 이외의 중금속에 대해서도 내성을 나타냈다. 고도 cadmium 내성균인 Erwinia sp. C-7 균은 50ppm의 C$d^{2+}$ 함유 배지에 28$^{\circ}C$, 24시간 진탕배양하므로 배지중의 cadmium을 57.2%, 28.60 mg /g dry cell의 cadmium을 군체내에 축적하였다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2023년도 춘계학술대회
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• pp.105-105
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• 2023

Heavy metals, including lead (Pb) toxicity, are increasing in soil and are considered toxic in small amounts. Pb contamination is mainly caused by industrialization - smelting, mining. Agricultural practices - sewage sludge, pests and urban practices - lead paint. It can seriously damage and threaten crop growth. Pb can adversely affect plant growth and development by affecting the photosystem, cell membrane integrity, and excessive production of reactive oxygen species (ROS) such as hydrogen peroxide (H₂O₂)andsuperoxide(O₂.-). NO is produced via enzymatic and non-enzymatic antioxidants to scavenge ROS and lipid peroxidation substrates in terms of protecting cells from oxidative damage. Thus, NO improves ion homeostasis and confers resistance to metal stress. Our results here suggest that exogenous NO may aid in better growth under lead stress. These enhancements may be aided by NO's ability in sensing, signaling and stress tolerance in plants under heavy metal stress in combination with lead stress. Our results show that GSNO has a positive effect on soybean seedling growth in response to axillary pressure and that NO supplementation helps to reduce chlorophyll maturation and relative water content in leaves and roots following strong burst under lead stress. GSNO supplementation (200 µM and 100 µM) reduced compaction and approximated oxidative damage of MDA, proline and H₂O₂. Under plant tension, a distorted appearance was found in the relief of oxidative damage by ROS scavenging by GSNO application. In summary, modulation of these NO, PCS and prolongation of metal past reversing GSNO application confirms the detoxification of ROS induced by toxic metal rates in soybean. In summary, these NO, PCS and metal traditionally sustained rates of reverse GSNO application confirm the detoxification of ROS induced by toxic metal rates in soybean.

• Bulletin of the Korean Chemical Society
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• 제32권10호
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• pp.3592-3596
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• 2011

A novel poly(vinylchloride)-based membrane sensor using $N^1$,$N^3$,$N^5$-tris(2-(2,3-dihydroxybenzylamino)-ethyl)cyclohexane-1,3,5-tricarboxamide (CYCOENCAT, L) as ionophore has been prepared and explored as $Fe^{3+}$ selective electrode. The membrane electrode composed of ionophore, poly(vinylchloride) and o-nitropheyloctyl ether in the optimum ratio 4:33:63 gave excellent potentiometric response characteristics, and displayed a linear log[$Fe^{3+}$] versus EMF response over a wide concentration range of $1.0{\times}10^{-5}-1.0{\times}10^{-1}$ M with super nernstian slope of 28.0 mV/decade and the detection limit of $8.0{\times}10^{-6}$ M. The proposed ion selective electrode showed fast response time (< 15 s), wide pH range (3.0-7.0), high non-aqueous tolerance (up to 20%) and adequate long life time (120 days). It also exhibited very good selectivity for $Fe^{3+}$ relative to a wide variety of alkali, alkaline earth, transition and heavy metal ions. Further, the analytical applicability of the sensor was tested as an indicator electrode in the potentiometric titration of $Fe^{3+}$ with EDTA.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.144-144
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• 2017

Micronutrients such as zinc (Zn), iron (Fe), manganese (Mn) have important roles for development and growth in plants but it also have roles in animals and humans. In previous studies, a Korean weedy rice, KH2J was selected to have tolerance to heavy metal, lead (Pb) compared with a cultivar, Milyang23. To identify QTLs for micronutrients concentration in grain, an F2 population (120 plants) were developed from a cross between KH2J and an indica rice cultivar, Milyang23. To measure the concentration of eight ions, Zn, Fe, Mn, Pb, calcium (Ca), copper (Cu), cadmium (Cd) and arsenic (As), grains were collected and digested with 65% nitric acid, and the ion contents were measured using inductively coupled plasma mass spectrometry. A total 27 putative quantitative trait loci (QTLs) were detected on 12 chromosomes by single point analysis and 22 putative QTLs were detected by composite interval mapping. The co-locations of QTL for Zn, Fe and Mn were observed on chromosome 5. The QTLs for Cd, Cu and Zn were co-localized on chromosome 10, and QTLs for Zn, As and Mn was on chromosome 12. The Zn concentration in F2 generation showed significant correlation with concentrations of As (r = -0.4), Cu (r = 0.5) and Fe (r = 0.2) (P < 0.01). Also, the Ca concentration was significantly related with Mn and Fe concentrations (P < 0.01). Fine mapping of these QTLs is underway to analyze their functional relationship.