• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.323-326
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• 2002

Oxygen uptake characteristics of soil microcosm added by hydrocarbon degrading bacteria screened from polluted site in Korea was studied. The degradation of TPH was enhanced by additon of nononionic surfactants. The amount of oxygen consumed was decreased at higher concentration. The degradation rate of hydrocarbon was decreased by increasing the hydrcarbon concentration.

• KSBB Journal
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• v.18 no.6
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• pp.529-535
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• 2003

We studied degradation effects of hydrophobic substrate such as kerosene and diesel by adding a biosurfactant originated from Pseudomonas aeruginosa F722 and chemical surfactants (Tween 80 and detergent) with aeration. The surface tensions of the biosurfactant, Tween 80 and detergent were 30mN/m, 39mN/m and 31mN/m, respectively. When the concentration of biosurfactant added in C-medium was 0.01 and 0.15%(w/v), the ratios of hydrocarbon degradation were 94.3％ and 94.2% respectively. It was 6.2%(w/v) higher than when the concentrations of added biosurfactant were 0.05, 0.1 and 0.2％. The degradation ratios of the chemical surfactants (Tween 80 and detergent) were 94.5％ and 93.5％ respectively. The effects of the biosurfactant and chemical surfactants were similar on the degradation ratio in mixtures of kerosene and diesel. However, the population of viable p. aeruginosa F722 at the end of the cultivation period was twice as higher in the biosurfactant than that in the chemical surfactant. We also studied the effect of aeration (0.5vvm) on the degradation ratio. The biosurfactant addition experiment was conducted with 0.5vvm air, 35$^{\circ}C$, 150rpm, pH 8.0, 3days, 1.0% (w/v) substrate. When p. aeruginosa F722 and 0.15%(w/v) biosurfactant were added, the degradation ratio of hydrocarbon was 94.8％. Without p. aeruginosa F722, it was 68%. Thus, with aeration, the degradation ratio of hydrocarbon was increased by 26.8％. In addition, the cultivation time was shortened by 1/3. The degradation ratios of hydrocarbon in shaking culture (cultivation time; 3days) and stationary culture (cultivation time; 10days) were 94.8 and 93.7％ respectively. Thus, the addition of biosurfactant and aeration enhanced the degradation of hydrocarbon originated kerosene and diesel.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.297-300
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• 2004

The various microbial tests were performed to determine bioremediation agent capacity for eight strains isolated from the oil contaminated regions. Two tests for isolated strains were conducted such as cell hydrophobicity and emulsifying activity. The biodegradation of SHM (saturated hydrocarbon mixture) and AHM (aromatic hydrocarbon mixture) with the strains also was carried out. The strains having higher cell hydrophobicity and emulsifying activity degraded petroleum oil effectively. The degradation capacity for SHM was represented more than 90% in YS-7 and WLH-1 of isolated strains, and KH3-2 were capable of degrading AHM. Especially, WLH-1 as yeast was shown more than two or three times in the degradation capacity of automobile engine lubricants and the biomonitoring results of contaminated soil for residual oil degrading test showed that the hydrocarbon biodegradation was increased in the second treatment by this strain.

• KSBB Journal
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• v.15 no.3
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• pp.247-253
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• 2000

This study was aimed to enhance polycyclic aromatic hydrocarbon(PAHS) biodegradation rate by repeated-batch treatment using immobilized cells of Phanerochaete chrysosporium. In the repeated-batch operations with 30 mg/L of pyrene the maximum degradation rate was 6.58 mg/L day. As the number of batches increased the concentration of immobilized cells significantly decreased and the degradation rate and specific acitivity gradually increased to a maximum value and then decreased. To have PAH degradation activity and cell mass recovered one batch of cultivation using the growth medium instead of the PAH-degrading medium was carried in the course of repeated-batch operations. This maximum degradation rates of pyrene and anthracene were 4.29 and 4.46 mg/L$.$day respectively. Overall the rate of PAH degradation could be enhanced 2.5-30 folds by using immobilized cells compared to the case of using suspended cells.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.12
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• pp.1656-1667
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• 1997

Condensing heat transfer characteristics of hydrocarbon refrigerants are experimentally investigated. Single component hydrocarbon refrigerants (propane, isobutane, butane and propylene) and binary mixtures of propane/isobutane and propane/butane are considered as test fluids. Local condensing heat transfer coefficients of selected refrigerants are obtained from overall conductance measurement. Average heat transfer coefficients at different mass fluxes and heat transfer rates are shown and compared with those of R22. Pure hydrocarbon refrigerants have higher values of heat transfer coefficient than R22. It is also found that there is a heat transfer degradation for hydrocarbon mixtures due to composition variation during condensation. Measured condensing heat transfer coefficients are compared with predicted values by available correlations. An empirical correlation for pure and mixed hydrocarbon is developed, and it shows good agreement with experimental data.

• Molecules and Cells
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• v.43 no.11
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• pp.935-944
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• 2020

Aryl hydrocarbon receptor nuclear translocator (ARNT) plays an essential role in maintaining cellular homeostasis in response to environmental stress. Under conditions of hypoxia or xenobiotic exposure, ARNT regulates the subset of genes involved in adaptive responses, by forming heterodimers with hypoxia-inducible transcription factors (HIF1α and HIF2α) or aryl hydrocarbon receptor (AhR). Here, we have shown that ARNT interacts with DDB1 and CUL4-associated factor 15 (DCAF15), and the aryl sulfonamides, indisulam and E7820, induce its proteasomal degradation through Cullin-RING finger ligase 4 containing DCAF15 (CRL4^DCAF15) E3 ligase. Moreover, the two known neo-substrates of aryl sulfonamide, RNA-binding motif protein 39 (RBM39) and RNA-binding motif protein 23 (RBM23), are not required for ARNT degradation. In line with this finding, aryl sulfonamides inhibited the transcriptional activities of HIFs and AhR associated with ARNT. Our results collectively support novel regulatory roles of aryl sulfonamides in both hypoxic and xenobiotic responses.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.94-94
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• 1998

No Abstract, See Full Text

• Proceedings of the Microbiological Society of Korea Conference
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• 2008.05a
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• pp.49-50
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• 2008

• Journal of Microbiology and Biotechnology
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• v.19 no.7
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• pp.651-657
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• 2009

Shifts in the activity and diversity of microbes involved in aliphatic and aromatic hydrocarbon degradation in contaminated soil were investigated. Subsurface soil was collected from a gas station that had been abandoned since 1995 owing to ground subsidence. The total petroleum hydrocarbon content of the sample was approximately 2,100 mg/kg, and that of the soil below a gas pump was over 23,000 mg/kg. Enrichment cultures were grown in mineral medium that contained hexadecane (H) or naphthalene (N) at a concentration of 200 mg/l. In the Henrichment culture, a real-time PCR assay revealed that the 16S rRNA gene copy number increased from $1.2{\times}10^5$to $8.6{\times}10^6$with no lag phase, representing an approximately 70-fold increase. In the N-enrichment culture, the 16S rRNA copy number increased about 13-fold after 48 h, from $6.3{\times}10^4$to $8.3{\times}10^5$. Microbial communities in the enrichment cultures were studied by denaturing gradient gel electrophoresis and by analysis of 16S rRNA gene libraries. Before the addition of hydrocarbons, the gas station soil contained primarily Alpha- and Gammaproteobacteria. During growth in the H-enrichment culture, the contribution of Bacteriodetes to the microbial community increased significantly. On the other hand, during N-enrichment, the Betaproteobacteria population increased conspicuously. These results suggest that specific phylotypes of bacteria were associated with the degradation of each hydrocarbon.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.578-581
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• 2001

A treatability study was conducted using a hydrocarbon-contaminated soil for the oPtimization of bioremediation strategy best fit to a given set of contamination. The applicability of nutrients, biosurfactant, and oil-degrading microorganisms were examined by monitoring $CO_2$ evolution and oil degradation The addition of inorganic nutrients in the form of slow released fertilizer accelerated the initial rate of $CO_2$ evolution by a factor of 3. The application of oil-degrading microorganisms did not significantly increased $CO_2$ evolution or biodegradation efficiency. Application of a commercial biosurfactant was most effect in terms of the total $CO_2$ evolution and the oil degradation rate. The results indicate that $CO_2$ evolution measurement was found to be a simple and reliable countermeasure of crude oil hydrocarbon mineralization for the rapid determination of the best-fit bioremediation strategy.