• Korean Journal of Microbiology
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• v.54 no.4
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• pp.463-464
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• 2018

Tamlana sp. UJ94 isolated from seawater can degrade alginate. To identify the genomic basis of this activity, the genome was sequenced. The genome was composed of 4,116,543 bp, 3,609 coding sequences, and 35.2 mol% G + C content. A BLASTp search predicted the presence of 9 alginate lyases as well as 6 agarases, 5 amylases, 4 carrageenases, 1 cellulase, 4 pectate lyases, and 7 xylanases, indicating its ability to degrade diverse polysaccharides. The genome of strain UJ94 is a source of polysaccharide-degrading enzymes for bioconversion processes.

• Microbiology and Biotechnology Letters
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• v.43 no.2
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• pp.105-111
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• 2015

An alginate degrading enzyme from the Vibrio crassostreae PKA 1002 strain was used to hydrolyze the water extract of Sargassum thunbergii. To obtain the optimum degrading conditions for the S. thunbergii water extract, the mixture of the water extract and enzyme was incubated at 30℃ for 0, 3, 6, 12, and 24 h, and its alginate degrading ability was measured by reducing sugar and viscosity. A temperature of 30℃ for a period of 6 h was found to be the optimal condition for the enhancement of the alginate’s degrading ability. The pH of the enzymatic hydrolysate was not significantly different from that of the water extract. Overall lightness decreased, but redness and yellowness increased after enzymatic hydrolysis. Total phenolic compounds did not differ between the water extract and the enzymatic hydrolysate. DPPH radical scavenging activity and the reducing power of the enzymatic hydrolysate were lower than those of the water extract. However, the chelating effect of the enzymatic hydrolysate (80.08% at 5 mg/ml) was higher than that of the water extract (62.29%). These results indicate that the enzymatic hydrolysate possesses an anti-oxidant activity by way of the action of the chelating effect.

• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1169-1176
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• 2007

Genes encoding proteins responsible for limonene catabolism were cloned from a limonene-degrading microorganism, Enterobacter cowanii 6L, which was isolated from citron (Citrus junos) peel. The 8.6, 4.7, and 7.7 kb fragments (CD3, CD4, and CD6) of E. cowanii 6L chromosomal DNA that confer to E. coli the ability to grow on limonene have been cloned and their corresponding DNA sequences were determined. Nine open reading frames (ORFs) were identified, and the four ORFs (921 bp of CD3-2; 1,515 bp of CD4-1; 1,776 bp of CD6-1; and 1,356 bp of CD6-2) that encode limonene hydroxylase were confirmed by independently expressing these genes in E. coli. FAD and NADH were found to stimulate the hydroxylation reaction if added to cell extracts from E. coli recombinants, and multiple compounds (linalool, dihydrolinalool, perillyl alcohol, (${\alpha}-terpineol$, and ${\gamma}-terpineol$) were the principal products observed. Our results suggest that the isolate E. cowanii 6L has a broad metabolic capability including utilization of limonene. This broad metabolic ability was confirmed by identifying four novel limonene hydroxylase functional ORFs in E. cowanii 6L.

• Proceedings of the Korean Environmental Health Society Conference
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• 2002.04a
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• pp.9-12
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• 2002

Diffusive transport of volatile organic compounds(VOCs) and their degradation by bacteria in unsaturated soils are couple by poorly understood mass transfer kinetics at the gas/water interface. Determination of the fate of VOCs in unsaturated soil is necessary to evaluate the feasibility of natural attenuation as a VOC remediation strategy. The objective of this study was to develop a mechanistically based mathematical model that would consider the interdependence of VOC transport, microbial activity, and sorptive interaction in a moist, unsaturated soil. Because the focus of the model was on description of natural attenuation, the advective VOC transport that is induced in engineered remediation processes such as vapor extraction was not considered. The utility of the model was assessed through its ability to describe experimental observations form diffusion experiments using toluene as a representative VOC in well-defined soil columns that contained a toluene degrading bacterium, Pseudomonas Putida, as the sole active microbial species. The coefficient for gas-liquid mass-transfer, K$\sub$LA/, was found to be a key parameter controlling the ability of bacteria to degrade VOCs. This finding indicates that soil size and geometry are likely to be important parameters in assessing the possible success of natural attenuation of VOCs in contaminated unsaturated soils.

• Journal of environmental and Sanitary engineering
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• v.19 no.4 s.54
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• pp.19-24
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• 2004

The objective of this study was to develop a mechanistically based mathematical model that would consider the interdependence of VOCs transport, microbial activity, and sorptive interactions in a moist, unsaturated soil. Because the focus of the model was on description of natural attenuation, the advective VOCs transport that is induced in engineered remediation processes such as vapor extraction was not considered. The utility of the model was assessed through its ability to describe experimental observations from diffusion experiments using toluene as a representative VOCs in well-defined soil columns that contained a toluene degrading bacterium, Pseudomonas putida G7 md Fl, as the sole active microbial species. The gas-liquid mass-transfer was found to be a key parameter controlling the ability of bacteria to degrade VOCs. This finding indicates that soil size and geometry are likely to be important parameters in assessing the possible success of natural attenuation of VOCs in contaminated unsaturated soils. Therefore we found that Pseudomonas putida G7 and Fl were very effective to remove of refractory pollutants such as toluene in soil by Bio-filter

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.807-810
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• 2008

Permeable reactive barriers containing Zero-valent iron (ZVI) are used to purify ground-water contaminants. One of the representative contaminant is trichloroethylene (TCE). ZVI can act as a reducing agent of TCE. When ZVI is oxidized to Ferric iron, TCE reduced to Ethene, which is non-harmful matter. As a ZVI becomes ferric iron, the reducing effect decreases and iron becomes unavailable. So, constant reduction of TCE requires the regular supply of reducing agent. So, we use Iron-reducing bacteria(IRB) to extend the TCE degrading ability. We perform three experiment DI water, DI water with medium, and DI water with medium and IRB. By the experiment we try to found the dissolve ability.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.1
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• pp.17-23
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• 2004

The semi-active suspension system is getting widely adopted in passenger vehicles for its ability to improve ride comfort over the passive suspension system while not degrading driving safety. A key to the success is to develop practical controllers that yield performance enhancement over the passive damper under various driving conditions. To this end, several control strategies have been studied and evaluated in this research in consideration of practical aspects such as nonlinearity and dynamics of the damper. From simulation results. it has been observed that, with the proposed control schemes, ride comfort can be significantly upgraded while suppressing degradation of driving safety.

• Journal of Environmental Science International
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• v.7 no.4
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• pp.473-480
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• 1998

The bacterial strain JE-1 degrading and utilizing Congo Red as a sole carbon source was isolated from dye-contaminated soul and Identified as Enterobacter species. Enterobacter sp. JE-1 had the highesc decolorization ability when It was cultured In the medium containing 0.05% $NH_4N0_3, 0.05% K_2HP0_4, 0. 03%$ $MgSO_4$, $7H_2O$, 0.025% Congo Red, initial pH 7.0 at $30^{\circ}C$, respectively Enterobacter sp. n-1 had the relatively high substrate specificity. The dye decolorizing activity was exclusively extracellular. The expected metabolic intermediates of Congo Red by Enterobacter sp.15-1 were analyzed by GC/MS. As a result. metabolic products like hauadecanoic acid, 1, 2, 3-triphenylcyclopropene, aliphatic hydrocarbons butylester were detected. Benzldine 616 not detected.

• Journal of Microbiology and Biotechnology
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• v.1 no.1
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• pp.1-5
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• 1991

Sulfate-reducing bacteria have been isolated from soil and their abilities to degrade dibenzothiophene (DBT) were compared with those of type cultures. Among the strains tested a soil isolate M6 showed the highest ability to degrade DBT. Isolate M6 was characterized as a mesophilic obligatory anaerobe. The morphology of the bacterium was vibrioid with the size of $0.4-0.7{\;}\mu\textrm{m}{\;}by{\;}1.0-1.5{\;}\mu\textrm{m}$. Gram reaction was negative and nonsporulating. Desulfoviridin is present. Lactate, pyruvate, ethanol and malate supported growth of the bacterium in the presence of sulfate. Sulfate, sulfite, thiosulfate and sulfur served as electron acceptors for growth. Hydrogenase was present. The mol% of guanine and cytosine of DNA was determined as 56%. The bacterium produced viscous material. From these results, the isolate M6 was identified as Desulfovibrio desulfuricans.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.9
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• pp.1250-1260
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• 2010

Mycotoxins are secondary metabolites produced by fungi. These toxins pose serious health concerns to animals as well as human beings. Biodegradation of these mycotoxins has been considered as one of the best strategies to decontaminate food and feedstuffs. Biodegradation employs the application of microbes or enzymes to contaminated food and feedstuffs. Ruminants are considered to be resistant to the adverse effects of mycotoxins presumably due to the biodegrading ability of rumen microbes compared to mono-gastric animals. Therefore, rumen microbial source or microbial enzyme could be a great asset in biological detoxification of mycotoxins. Isolation and characterization of pure culture of rumen microorganisms or isolation and cloning of genes encoding mycotoxin-degrading potential would prove to have overall beneficial impact in the food and feed industry.