• Applied Biological Chemistry
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• v.21 no.1
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• pp.1-10
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• 1978

In an effort to elucidate degradation mechanisms of an acetanilide herbicide, Butachlor, by soil microorganisms, a common soil fungus, Chaetomium globosum which is known to be powerful was selected and incubated in a Butachlor-contained medium. The results obtained from the resulting metabolites are as follows: (1) Dechlorination from Butachlor occurred very easily, remaining almost constant after 180 hrs. of incubation. (2) More than 10 metabolites were isolated and characterized, of which the metabolites, m/e 205, 177, 223, 182, and 206 were the main products. (3) In this paper, the structures and pathways of formation of metabolites, m/e 206, 182, 223, 225, and 189 were tentatively proposed.

• Applied Biological Chemistry
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• v.29 no.2
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• pp.182-189
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• 1986

Alachlor, 2-chloro-2',6'-diethyl-N-(methoxymethyl) acetanilide produced four major degradation products, when incubated under an upland soil condition for 80 days. They include 8-ethyl-2-hydroxy-N-(methoxymethyl)-1,2,3,4-tetrahydroquinoline (m/z 221), N-hydroxyacetyl-2,3-dihydro-7-ethylindole (m/z 205), 2-hydroxy-2',6'-diethyl-N-(methoxymethyl) acetanilide (m/z 251), and 9-ethyl-1,5-dihydrol-(methoxymethyl)-5-methyl-4,1-benzoxazepin-2 (3H)-one (m/z 249). The products turned out to be a little different from those obtained under the flooded paddy soil condition used in the previous paper. The plausible pathways for the degradation were proposed.

• Applied Biological Chemistry
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• v.32 no.3
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• pp.315-320
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• 1989

Bacteria utilizing naphthalene as a sole carbon source for growth were isolated and identified and code named as Acinetobacter calcoaceticus R-88, Pseudomonas testosteroni R-87 and Pseudomonas putida R-89. Among these isolates, A. calcoaceticus R-88 found most effective in utilizing naphthalene. The optimal pH, temperature and concentration of naphthalene was 7.0, $30^{\circ}C$ and 10mM, respectively. The strain degraded naphthalene to salicylic acid as an intermediate. And the strain showed to be resistant to ampicillin, tetracyclin, chloramphenicol and kanamycin. A. calcoaceticus R-88 harbored plasmid DNA which was believed to be involved in naphthalene degradation.

• Microbiology and Biotechnology Letters
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• v.17 no.3
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• pp.236-240
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• 1989

The isolated bacterial strain 1K1 able to grow on extremely high concentration of toluene was morphologically and physiologically best described as Pseudomonas putida. This strain could grow on at least eight aromatic compounds, e.g., benzene, benzoate, phenol, o-cresol, m-cresol, toluene, m-tolunte, and xylene, but did not Brow on alkanes, such as hexane, octane, decane, and cyclohexane. Strain 1K1 could grow on above 95% toluene, but it could not grow on above 1% of other aromatic compounds. In the point of survival, strain 1K1 was resistant to high concentration of alkanes, appreciably resistant to toluene and xylene, and damaged by to other aromatic compounds. Strain 1K1 which grew on high concentration of toluene had irregular cell shape in comparing with normal cell shape of the genus Pseudomonas. Strain 1K1 was shown to have at least two aromatic compound dissimilation pathway, one for benzoate and the other for toluene.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1057-1072
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• 2018

In this study, micro-sized $CeO_2$ particles were synthesized by spray pyrolysis, and EG(ethylene glycol) and CA(citric acid) as organic additives were added to obtain hollow and porous particle during spray pyrolysis, and characteristics of obtained ceria were investigated according to the amount of added organic additives. Spray pyrolysis, postheat and ball-milling were combined to give 6 paths. $CeO_2$ nano-sized particle was obtained by the path which has sequence of Spray Pyrolysis with 0.5 M of EG and CA${\rightarrow}$Post-heat${\rightarrow}$Ball-milling${\rightarrow}$Post-heat among 6 paths. The average particle size(24 nm with standard deviation of 3.8 nm) of $CeO_2$ nano-sized particle by TEM analysis is close to the primary particle size(20 nm) which was calculated by Debye-Scherrer equation. To investigate the morphological characteristics and structure of the synthesized nanoparticle powders, SEM(Scanning Electron Microscopy), XRD(X-Ray Diffractometer) and TEM(Transmission Electron Microscopy) were used.

• Journal of Life Science
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• v.31 no.10
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• pp.954-959
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• 2021

Apoptosis is an important mechanism that regulates cellular populations to maintain homeostasis, and the caspases, a family of cysteine proteases, are key mediators of the apoptosis pathway. Caspase-8 is an initiator caspase of the extrinsic apoptotic pathway, which is initiated by extracellular stimuli. Caspase-8 have two conserved domains, N-terminal tandem death effector domains (DED) and C-terminal two catalytic domain, which are important for this extrinsic apoptosis pathway. In extrinsic apoptosis pathway, death receptors which members of TNF superfamily are activated by binding of death receptor specific ligands from cell outside. After the activated death receptors recruit adaptor protein Fas-associated death domain protein (FADD), death domains (DD) of death receptor and FADD bind to each other and FADD combined with death receptor recruits procaspase-8, a precursor form of caspase-8. The DED of FADD and procaspase-8 bind to one another and FADD-bound procaspase-8 is activated by cleavage of the prodomain. This death receptor-FADD-caspase-8 complex called death inducing signaling complex (DISC). Cellular FLICE-inhibitory proteins (c-FLIPs) regulate caspase-8 activation by acting both anti- and pro-apoptotically, and caspase-8 activation initiates the activation of executioner caspases such as caspase-3. Finally activated executioner caspases complete the apoptosis by acting critically DNA degradation, nuclear condensation, plasma membrane blebbing, and the proteolysis of certain caspase substrates.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.6
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• pp.751-758
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• 2019

This study tested various assumptions that simplified the configuration of the numerical model for unsaturated zone's contaminant transport to simulate the pathway to exposed point. This study investigated the contaminant migration through in the pollutant exposure pathway of vadoze zone for risk assessment of the contaminated site. For the purpose, generic scenarios as well as contaminant-based scenarios were simulated using the numerical code for transport of the contaminant in the pathway. The finite-difference one-dimensional transport with adsorption and biodegradation were considered, and it also assumed that the initial concentration was also depleted over time. The results of the generic-scenario show that as the groundwater infiltration rate decreases, the longer the path from the source to the groundwater level, the lower the concentration at the point of inflow into the groundwater level. In particular, in the case of high biodegradation rate and rapid depletion of pollutant sources, statistically outliers were found in the simulated results and generic scenarios was good at prediction.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.4
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• pp.49-56
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• 2003

The strain Ralstonia eutopha JMP134 (formerly Alcaligenes eutrophus JMP134) can degrade trichloroethylene(TCE) through a chromosomal phenol-dependent pathway. The phenol hydroxylase was previously found to be a single responsible enzyme for TEC degradation. Here, we demonstrate that a recombinant bacterium, R. eutopha AEK301, one of Tn5-induced mutants of JMP134 containing a recombinant plasmid pYK3011, degrades TCE in the absence of inducer, phenol and in the presence of various carbon sources. Complete removal of TCE ($50{\mu}M$) was observed in minimal medium containing only 0.05% ethanol as a carbon source within 24 hours. The bacterium removed $200{\mu}M$ of TCE to below detectable level within two days under non-selective pressure. When TCE concentration was increased up to $400{\mu}M$, the degradation had been continued until two days, then ceased with removal of 70% of detectable TCE.

• Korean Journal of Environmental Agriculture
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• v.29 no.4
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• pp.388-395
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• 2010

In order to decrease level of an organophosphorus fungicide, tolclofos-methyl, from in situ ginseng cultivating soil, we isolated a tolclofos-methyl degrading bacteria from ginseng cultivating soil samples. The bacterial strain removed tolclofos-methyl around 95% after 3 days incubation with complete liquid media. The strain was identified as Sphingomonas sp. by 16S rDNA sequence comparison, and designated as Sphingomonas sp. 224. Through the GC-MS analysis, Sphingomonas sp. 224 was proposed to have an initiative degradation pathway generating the metabolite such as 2,6-dichloro-4-methyl phenol compound from tolclofos-methyl. In addition, Sphingomonas sp. 224 was confirmed representing the effective degrading capability to tolclofosmethyl in situ soil.

• Korean Journal of Environmental Agriculture
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• v.6 no.2
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• pp.1-11
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• 1987

The degradation of two chemicals seem to be clearly affected by soil microbial activity in submerged soil $conditions(30{\pm}1^{\circ}C)$. The Active ingredient of Diazinon disappeared about 5 times faster than that of Dursban. By Applying 300% higher concentrations of both chemicals. under the above soil conditions, however, degradation was retarded by about one day. Some of the metabolites of Diazinon were as follows: 0.0-diethyl phosphorothioate and sulfotep as hydrolytic products, and diazoxon, 0.0-diethyl-0-[2-(1-hydroxy-1, 1-dimethyl)-6-methyl]-pyrimidinyl phosphorothioate and 2-isopropyl-6-methyl-pyrimidine-4-one as degradation products of monooxygenase. But 0. 0-diethyl phosphorothioate was the only methabolite of Dursban.