• Journal of Environmental Science International
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• v.6 no.2
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• pp.173-182
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• 1997

The bacterial strains, which utilizes 2,4,4'-trichloro-2'-hydroxydiphenyl ether(TCHDPE) as a sole carbon source, were isolated by selective enrichment culture from soil samples of industrial waste deposits. The bacterium that showed the highestt biodegradation activity was designated as EL-O47R The isolated strain EL-O47R was Identified as the genus Pseudomonas from the results of morphological, cultural, and biochemical tests. The optimum conditions of medium for the growth and the degradation of TCHDPE were TCHDPE 500 ppm, (NH4)2SO4 0.1% as the nitrogen source, initial pH 7.0±0.1, and 37℃, respectively. In this conditions, the regradation rate of TCHDPE was about 97%. Pseudomonas sp. EL-O47R was tested for resistance to several metal compounds and antibiotics. Pseudomonas sp. EL-O47R was moderately grown to Cd(NO3)2, ZnCl2, AgSO4, CuSO4 and HgCl2. This strain was sensitive to rifampicin and kanamycln but resistant to ampicillin, penicillin, tetracyclin and chloramphenlcol. Pseudomonas sp. EL-O47R was grown structurally related com- pounds and potential metabolites of TCHDPE, and has the stability on TCHDPE biodegradation.

• Microbiology and Biotechnology Letters
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• v.26 no.4
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• pp.352-357
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• 1998

Biodegradation of benzoate and m-toluate was investigated using a Pseudomonas sp. isolated in a continuous culture for 45 days with a step-wise increase of the subsrates. The optimum mixture ratio of benzoate and m-toluate was 75% and 25%, respectively. During 45-day culture, removal of benzoate and m-toluate, which was replaced 2,000 ppm on the 30th day were 94% and 79%, respectively, when COD removal rate was 80%. The enzymatic activity of catechol 1,2-dioxygenase increased and that of catechol 2,3-dioxygenase decreased as the concentration of m-toluate was increased. These results suggested that m-toluate induced enzyme activity for degradation of benzoate. The shape of isolated strain in the continuous culture was investigated with SEM and the results showed that the cell shape was more damage according to the higher concentration of aromatic hydrocarbons. Therefore, we suggested that the tolerance against aromatic hydrocarbons was related to not only enzymatic activity but also characteristic of cell membrane or cell wall.

• Journal of Korea Soil Environment Society
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• v.5 no.1
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• pp.97-108
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• 2000

A Gram-type negative bacteria that can utilize crude oil as the sole source of carbon and energy was isolated from an activated sludge of a local sewage treatment plant and identified tentatively as belonging to the genus Acinetobacter. The isolate could degrade n-alkanes and unidentified hydrocarbons in crude oil and utilize n-alkanes, hydrophobic substrates, as sole carbon and energy sources. n-Alkanes from tridecane (Cl3) to triacontane (C30) in crude oil were degraded simultaneously with no difference in degradation characteristics between the two close odd and even numbered alkanes in carbon numbers. The linear growth of the isolate and the degradation characteristics of Pr-alkanes suggested that the transport of substrates from the oil phase to the site where the substrates undergo the initial oxidation in microorganism might be the rate limiting in the biodegradation process of crude oil constituents. The remainder fraction of substrates after cultivation was considered to reflect the hydrocarbon inclusions in the cell mass, characteristics in Acinetobacter species, and to control the transport of substrates from crude oil phase. On the basis of the results, the isolate was considered to play an important role in the degradation study of hydrophobic environmental pollutants.

• Journal of Soil and Groundwater Environment
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• v.10 no.3
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• pp.46-51
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• 2005

This study was to evaluate sorption and biodegradation rate affecting the natural dissipation of chlorinated volatile organic compounds (CVOCs) in surface soil. To show the effect of sorption and biodegradation on the natural dissipation of 1,1,1-trichloroethane (TCA), trichloroethylene (TCE) and tetrachloroethylene (PCE), three types of vial experiments were employed; (1) sterilized, (2) non-sterilized, (3) non-sterilized/substrate enriched. Also three moisture contents was applied to find the moisture effect in each vial; (1) wilting point (12%, w/w), (2) field capacity (29%, w/w), (3) saturation (48%, w/w). The results suggested that keeping the soil moisture content at field capacity was desirable for TCA and TCE natural dissipation in the vial study.

• Journal of Microbiology and Biotechnology
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• v.27 no.7
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• pp.1306-1315
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• 2017

DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane) is one of the organic synthetic pesticides that has many negative effects for human health and the environment. The purpose of this study was to investigate the synergistic effect of mixed cutures of white-rot fungus, Pleurotus ostreatus, and biosurfactant-producing bacteria, Pseudomonas aeruginosa and Bacillus subtilis, on DDT biodegradation. Bacteria were added into the P. ostreatus culture (mycelial wet weight on average by 8.53 g) in concentrations of 1, 3, 5, and 10 ml ($1ml{\approx}1.25{\times}10^9$ bacteria cells/ml culture). DDT was degraded to approximately 19% by P. ostreatus during the 7-day incubation period. The principal result of this study was that the addition of 3 ml of P. aeruginosa into P. ostreatus culture gave the highest DDT degradation rate (approximately 86%) during the 7-day incubation period. This mixed culture combination of the fungus and bacteria also gave the best ratio of optimization of 1.91. DDD (1,1-dichloro-2,2-bis(4-chlorophenyl) ethane), DDE (1,1-dichloro-2,2-bis(4-chlorophenyl) ethylene), and DDMU (1-chloro-2,2-bis(4-chlorophenyl) ethylene) were detected as metabolic products from the DDT degradation by P. ostreatus and P. aeruginosa. The results of this study indicate that P. aeruginosa has a synergistic relationship with P. ostreatus and can be used to optimize the degradation of DDT by P. ostreatus.

• Journal of Soil and Groundwater Environment
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• v.21 no.1
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• pp.94-103
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• 2016

Landfarming that supplies aerobic biodegradation condition to indigenous microbes in soils is a biological remediation technology. In this research, volatilization and biodegradation rate by indigenous microbes in the soil contaminated with total petroleum hydrocarbons (TPH) were measured. Soils were contaminated with diesel artificially and divided into two parts. One was sterilized by autoclave to remove indigenous microorganism and the other was used as it was. Various moisture contents and number of tillings were applied to the soil to find out proper condition to minimize volatilization and enhance bioremediation. Volatilization of TPH was inhibited and biodegradation was enhanced by increase on moisture content. Tilling was usually used to supply air for microbes, but tillings did not affect the growth of microbes in our study. Enough moisture content and proper aeration are important to control volatilization in landfarming. Also, TPH degradation was a function of the microbe counts (x₁), numbers of tilling (x₂), and moisture content (x₃) from the application of the response surface methodology. Statistical results showed the order of significance of the independent variables to be microbe counts > numbers of tilling > moisture content.

• Journal of Animal Environmental Science
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• v.6 no.3
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• pp.133-140
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• 2000

This study was carried out to determine a suitable mixing rate to utilize the PDF as a bedding materials at the pigpens and investigate the effect of substitute processed dustproof fly-ash(PDF) on the odor. In proportion to the increase of substitute rate of the PDF, the utilizable period was extended, and there was a little change of the moisture in the bedding materials. At all the treatment of PDF, there was the significant effect on the maggots and parasites but it didn\`t hinder in the biodegradation. According to highly mixing rate, PDF decreased in the noxious gas ($NH_3$ and $H_2$S) emission. In conclusion, the mixing rate of 30% or above this substituted level will increase replacement terms, and reduce the sawdust cost and the pollutions of breed pigs.

• Journal of Food Hygiene and Safety
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• v.11 no.3
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• pp.165-170
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• 1996

The biodegradation of high concentration of benzoate by enrichment culture with Pseudomonas sp. was investigated. During 50 days continuous culture, average of removal rate of benzoate and COD were 90% and 83%, respectively. And the enzymatic activity of catechol 2,3-dioxygenase was determined in the continuous culture but not Catechol 1,2-dioxygenase. On the other hand, Pseudomonas sp in the culture was investigated with SEM and the result was revealed that the cell shape was more demage according concentration of benzoate.

• 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.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.7 s.144
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• pp.1027-1036
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• 2005

Based on the correlation analysis result of preceding research, the biodegradabilities of cellulose fibers were closely related to the moisture regain of the samples, which reflects the hydrophilicity and internal structure of the fibers. In addition to this factor, it was expected that the biodegradation conditions influence the biodegradability of fibers. In this study, widely used cellulose fibers including cotton, rayon, and acetate were used. The biodegradabilities of cellulose fibers were measured by soilburial test, and then the degradation behaviors based on each condition were compared. Moreover, the effects of degradation conditions such as humidity of the soil were investigated. Changes in the internal structure of samples were also observed by X-ray analysis according to the soil burial time. It was shown that humidity of soil facilitated the degradation of cotton, rayon, and acetate fibers, showing higher degradation rate with higher humidity in soil. This effect was shown to be much greater in the fibers of high moisture regain such as cotton and rayon. In respect of microstructure change, crystallinities and their crystal size of fibers decreased remarkably in the soil of higher humidity. It was revealed that degradation of crystalline area was more dependent on the soil humidity than that of amorphous area.