• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.374-377
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• 2000

A strain of Pseudomonas sp. BCNU 154 was isolated from contaminated soil with orangic solvents as the sole source of carbon and energy. It utilized an exceptionally wide aromatic substrates. The strain BCNU 154 was able to utilize toluene, p-xylene, ethylbenzene, cumene, as the only carbon and energy source. When toluene or p-xylene was used as the sole carbon and energy source, the compound was rapidly degraded with significant increase in biomass concentruction. The biodegradation of this compound was observed when ethylbenzene or cumene was supplied on the carbon source and energy source, which may be a candidate extremophilic bacterium for the bioremediation technology.

• Journal of Life Science
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• v.21 no.5
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• pp.700-705
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• 2011

Using enrichment procedures, we isolated organic solvent-tolerant Bacillus sp. BCNU 5005 from waste water and soil in the Ulsan industrial plant region. BCNU 5005 had a maximum similarity of 98% with B. subtilis and was designated as B. subtilis based on phylogenetic analyses using 16S rDNA sequences. Generally, most bacteria and their enzymes are destroyed or inactivated in the presence of high concentrations of organic solvents. However, the lipase activity of B. subtilis BCNU 5005 was very stable in the presence of various kinds of solvents (25%, v/v) except chloroform, ethylbenzene and decane. Furthermore, BCNU 5005 was determined to have a degradative ability towards organic solvents. This organic solvent tolerant Bacillus sp. BCNU 5005 could be used as a new potential resource for biotransformation and bioremediation.

• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.1005-1012
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• 2020

Acid mine drainage (AMD) has been a serious environmental issue that threatens soil and aquatic ecosystems. In this study, an acid-tolerant sulfate-reducing bacterium, strain S4, was isolated from the mud of an AMD storage pond in Vietnam via enrichment in anoxic mineral medium at pH 5. Comparative analyses of sequences of the 16S rRNA gene and dsrB gene involved in sulfate reduction revealed that the isolate belonged to the genus Desulfovibrio, and is most closely related to Desulfovibrio oxamicus (with 99% homology in 16S rDNA sequence and 98% homology in dsrB gene sequence). Denaturing gradient gel electrophoresis (DGGE) analyses of dsrB gene showed that strain S4 represented one of the two most abundant groups developed in the enrichment culture. Notably, strain S4 was capable of reducing sulfate in low pH environments (from 2 and above), and resistance to extremely high concentration of heavy metals (Fe 3,000 mg/l, Zn 100 mg/l, Cu 100 mg/l). In a batch incubation experiment in synthetic AMD with pH 3.5, strain S4 showed strong effects in facilitating growth of a neutrophilic, metal sensitive Desulfovibrio sp. strain SR4H, which was not capable of growing alone in such an environment. Thus, it is postulated that under extreme conditions such as an AMD environment, acid- and metal-tolerant sulfate-reducing bacteria (SRB)-like strain S4 would facilitate the growth of other widely distributed SRB by starting to reduce sulfate at low pH, thus increasing pH and lowering the metal concentration in the environment. Owing to such unique physiological characteristics, strain S4 shows great potential for application in sustainable remediation of AMD.

• Journal of Korean Society on Water Environment
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• v.40 no.1
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• pp.11-18
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• 2024

Recently, enhanced in situ bioremediation using slow substrate release techniques has been actively researched for managing TCE-contaminated groundwater. This study conducted a lab-scale batch reactor experiment to evaluate the feasibility of natural attenuation for TCE dechlorination using microsized corn-oil droplet (MOD) as an activator considering the following three factors: 1) TCE dechlorination in the presence or absence of MOD; 2) TCE dechlorination in the presence or absence of inactivator of native microbial activity; and 3) MOD concentration effects on TCE dechlorination. Batch reactors were constructed using site groundwater and soil in which Dehalococcoides bacteria were present. Without MOD, TCE was decomposed into dichloroethylene (DCE). However, other by-products of TCE dechlorination were not detected. With MOD, DCE, vinyl chloride (VC), and ethylene (ETH) were sequentially observed. This result confirmed that MOD effectively supplied electrons to complete dechlorination of TCE to ETH. However, when an excess of MOD was provided, it formed unfavorable conditions for anaerobic digestion because dechlorination reaction did not proceed while propionic acid was accumulated after DCE was generated. Therefore, if an appropriate amount of MOD is supplied, MOD can be effectively used as a natural reduction activator to promote biodegradation in an aquifer contaminated by TCE.

• Journal of Soil and Groundwater Environment
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• v.8 no.3
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• pp.37-44
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• 2003

Fuel oxygenates, such as Methyl tertiary Butyl Ether (MTBE) is additive in gasoline used to reduce air pollution. Gasoline components and fuel additives can leak: form underground storage tanks. MTBE is far more water soluble than gasoline hydrocarbons like BTEX then it travels at essentially the same velocity as groundwater. MTBE in drinking water causes taste and odor problems. Therefore, the purpose of the this study is to examine the ability of ground tire to sorb MTBE in water. The study consisted of running both batch and column tests to determine the sorption capacity, the required sorption equilibration time, and the flow through utilization efficiency of ground tire. The batch test result indicated that ground tire can attain equilibrium sorption capacities about 0.5 mg of MTBE. The result of column test indicate that ground tire has on the 36% utilization rate. Finally, it is clear that ground tire represented an attractive and relatively inexpensive sorption medium for a MTBE. Authors thought that to determine the economic costs of ground tire utilization, the cost to sorb a given mass of contaminant by ground tire will have to be compared to currently accepted sorption media. The cost comparison will also have to include regeneration and disposal cost.

• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.174-179
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• 2006

Bacterium capable of using biphenyl as a sole source of carbon and energy were isolated from soil, and based on the results of 16S rDNA sequence, strain BK10 identified as a Sphingobium yanoiktiyae. The optimum cultural conditions were as follows; $NH_4NO_3$ 1g, $K_2HPO_4$ 1g, $MgSO_4{\cdot}7H_2O$ 0.5g, $CaCO_3$ 0.2 g per 1 liter of distilled water. The Sphingobium yanoikuyae BK10 strain was completely utilized biphenyl in mineral salt media containing biphenyl at concentration 500 $\mu$g/ml of biphenyl as a sole carbon and energy source within 48 hours. Optimumal pH and temperature for biphenyl degradation and cell growth of strains were 6.0$\sim$8.0 and 20$\sim$50$^{\circ}C$, respectively. Especially, at 30$^{\circ}C$, cell-growth were higher than other temperature. Cell grown on biphenyl has been shown to have a higher removal rate for biphenyl than grown on sucrose. This study shows that Sphingobium yanoikuyae BK10 strain had a high biodegradation capability of biphenyl and can be simulate a candidate compounds the bioremediation of PCBs (Polychlorinated biphenyl) contaminant soil and water.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.273-278
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• 2007

As a model compound of PAHs (polycyclic aromatic hydrocarbons) phenanthrene has been regarded as a toxic material, mutagen and carcinogen in various animals. Biodegradation conditions of phenanthrene such as pH, temperature, shaking speed, stabilizer and cofactor of degrading enzymes were investigated with Trametes versicolor and its transformant T. versicolor MrP1 in YMG medium, minimal medium and soil microcosm. T. versicolor MrP1 can overexpress mrp gene encoding Mn-repressed peroxidase that is involved in fungal degradation. Biodegradations of phenanthrene by T. versicolor and T. versicolor MrP1 were optimally performed in conditions of weak-acid (pH 6.0), $30^{\circ}C$, shaken culture and medium containing 5 mM veratryl alcohol or tryptophan. In these optimal conditions, biodegradation of phenanthrene by T. versicolor MrP1 is 31% higher than that of wild type strain in a minimal medium for 20 days. Biodegradation of phenanthrene by T. versicolor MrP1 was also higher than that of wild type in soil microcosm. T. versicolor MrP1 can be a excellent candidate for the bioremediation of PAHs contaminated environments.

• Economic and Environmental Geology
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• v.36 no.5
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• pp.349-356
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• 2003

As industrial activities are growing, pollutants found in the contaminated land are getting diverse. Some contaminated areas are subject to mixed wastes containing both organic and inorganic wastes such as hydrocarbon and heavy metals. This study concerns with the influence of the degradation of organic pollutants on the coexisting heavy metals, expecially for As. As mainly exists as two different oxidation state; As(III) and As(V) and the conversion between the two chemical forms may be induced by organic degradation in the soil contaminated by mixed wastes. We operated microcosm in an anaerobic chamber for 60 days, using sandy loam. The soils in the microcosm are artificially contaminated both by tetradecane and As, with different combination of As(III) and As(V); As(III):As(V) 1:1, As(III) only and As(V) only. Although not systematic, ratio of As(III)/As(Total) increase slightly at the later stage of experiment. Considering complicated geochemical reactions involving oxidation/reduction of organic materials, Mn/Fe oxides and As, the findings in the study seem to indicate the degradation of the organics is connected with the As speciation. That is to say, the As(V) can be reduced to As(III) either by direct or indirect influence induced by the organic degradation. Although Fe and Mn are good oxidising agent for the oxidation of As(III) to As(V), organic degradation may have suppressed reductive dissolution of the Fe and Mn oxides, causing the organic pollutants to retard the oxidation of As(III) to As(V) until the organic degradation ceases. The possible influence of organic degradation on the As speciation implies that the As in mixed wastes may be have elevated toxicity and mobility by partial conversion from As(V) to As(III).

• Korean Journal of Plant Resources
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• v.18 no.2
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• pp.251-259
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• 2005

Three different floras(M. sinsinsis, A. vulgaris, Robinia pseudo-acacia) were collected from the granite(GR) and coal bearing shale area(CB) and analysed for their heavy metal elements with the representative soils. Regardless of the flora species, the CB were high in average contents. Among the correlation relationships, the CB were more distinctive than the GR, and the A. vulgaris showed higher correlations than the M. sinsinsis. In the same soils, the A. vutgaris showed high contents than the M. sinsinsis and Robinia pseudo-acacia, and the M. sinsinsis were high relative to the Robinia pseudo-acacia. In the comparisons of the flora, root parts were high in most of the elements except for Zn. In the soils, the CB were high in most of elements while As and Mo showed different contents between the GR and CB. In the comparison between soil and flora, soils of the GR were high in the V and Sc contents and low in Zn and Cu, while those of the CR were high in the Cr, V and Sc contents, and low in the Zn contents, Comparing with the soil contents, the M, sinsinsis in the GR were similar to Co and V contents while, in the CB, the M. sinsinsis were similar to the Ni, Cr, Co, Zn, Mo contents, and the Robinia pseudo-acacia were similar to the Ni, Zn, Cu contents. Overall results suggested that the M. sinsinsis and A. vulgaris should be eligible for the bioremediation of the soils polluted by heavy metal such as the CB.

• Journal of Soil and Groundwater Environment
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• v.10 no.1
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• pp.35-42
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• 2005

This research was investigated the applicability of the biofiltration technology for the removal of volatile organic carbons (VOCs) produced from the bioremediation of oil contaminated soil. Diesel was used as surrogate for oil and, two types of biofilter systems made of ceramic and polymer media were compared for the removal efficiencies of diesel VOCs at different inlet concentrations and space velocity (SV) conditions. During the first 30-d operation, the removal efficiencies of the biofilter packed with polymer and the biofilter packed with ceramic were investigated at constant SV of $153\;h^{-1}$ When inlet concentrations of diesel VOCs were below 10 ppmv, the average removal efficiencies of the polymer biofilter and the ceramic biofilter were average $67\%\;and\;75\%$, respectively. When the inlet concentration increased to 30 ppmv, the VOC removal efficiency in the polymer biofilter was $80\%$, while the average removal efficiency in the ceramic biofilter was $60\%. Effect of the inlet concentration and SV on the removal efficiency of total diesel VOCs was investigated. As SV increased from $153\;h^{-1}$ to $204\;h^{-1}$ and $306\;h^{-1}$, the removal efficiency of total diesel VOCs was decreased gradually. The average removal efficiency of the biofilter packed with polymer carrier was decreased from $82\%\;to\;80\%\;and\;77\%$. The biofilter packed with polymer carrier showed that the removal efficiency of benzene and toluene were maintained within the range of $81\%\~86\%$. In contrast, for the biofilter packed with ceramic carrier, when SV increased from $153\;h^{-1}$ to $204\;h^{-1}$ and $306\;h^{-1}$, the removal efficiency of benzene decreased from $87\%\;to79\%\;and\;74\% . respectively. The removal efficiency of toluene decreased from $80\%\;to\;77\%\;and\;76\%$ at SV of $153\;h^{-1},\;204\;h^{-1}\;and\;306\;h^{-1}$, and $306\;h^{-1}$, respectively.