• Journal of Microbiology and Biotechnology
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• v.7 no.4
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• pp.237-241
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• 1997

Two isolated strains, Comamonas testosteroni CPW301 and Arthrobacter ureafaciens CPR706, were able to use 4-chlorophenol (4-CP) as a sole carbon and energy source. CPW301 was found to degrade 4-CP via a meta-cleavage pathway in which the chloro-substituent was eliminated even when 4-chlorocatechol was cleaved by the catechol 2, 3-dioxygenase. In contrast, CPR706 removed chloride from 4-CP prior to the ring-fission reaction, producing hydroquinone as a transient intermediate during 4-CP degradation. CPR706 exhibited much higher tolerance for 4-CP than CPW301, which was indicated by the maximum degradable concentration and degradation rate.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.5
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• pp.282-287
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• 2007

Chloroanilines are aromatic amines used as intermediate products in the synthesis of herbicides, azo-dyes, and pharmaceuticals. 3,4-dichloroaniline (DCA) is the degradation product of some herbicides (diuron, propanil, and linuron) and of trichlorocarbanilide, a chemical used as an active agent in the cosmetic industry. The compound, however, is considered a potential pollutant due to its toxicity and recalcitrant property to humans and other species. With the increasing necessity for bioremediation, we sought to isolate bacteria that degraded 3,4-DCA. A bacterium capable of growth on 3,4-DCA as the sole carbon source was isolated from seaside sediment using a dilution method with a culture enriched in 3,4-DCA. The isolated strain, YM-7 was identified to be Pseudomonas sp. The isolated strain was also able to degrade other chloroaniline compounds. The isolated strain showed a high level of catechol 2,3-dioxygenase activity on exposure to 3,4-DCA, suggesting that this enzyme is an important factor in 3,4-DCA degradation. The activity toward 4-methylcatechol was 53.1% that of catechol, while the activity toward 3-methylcatechol, 4-chlorocatechol and 4,5-chlorocatechol was 18.1, 33.1, and 6.9%, respectively.

• Journal of Environmental Science International
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• v.22 no.9
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• pp.1089-1095
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• 2013

The degradation of 3-chlorophenol(3-CP) by various AOPs(Advanced Oxidation Processes) including the ultraviolet / hydrogen peroxide, the Fenton and the ultraviolet(UV)-Fenton process has been conducted. The highest removal efficiency for 3-CP in the aqueous phase was obtained by the UV-Fenton process among the AOPs. In the UV-Fenton process, The removal efficiency of 3-CP decreased with increasing pH in the range of 3 to 6, and it decreased with increasing initial concentration. As the intermediates of 3-CP by UV-Fenton reaction, 3-chlorocatechol, 4-chlorocatechol, and chlorohydroquinone were detected thus the degradation pathways were proposed.

• Journal of Microbiology
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• v.38 no.3
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• pp.183-186
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• 2000

Several types of bioluminescent reporter strains have been developed for the detection and monitoring of pollutant aromatics contaminating the environment. In this study, a bioluminescent reporter strain, E. coli SHP3, was constructed by fusing the luc gene of firefly luciferase with the promoter of pcbC responsible for the meta-cleavage of aromatic hydrocarbons. the bioluminescence expressed by the luc gene in the reporter was well triggered by the promoter when it was exposed to 2,3-dihydroxybiphenyI (2,3-DHBP) at 0.5 to 1 mM concentrations. The bioluminescent response was more extensive when the reporter strain was exposed to 5 mM catechol and 2 mM 4-chlorocatechol. These different types of bioluminescent responses by E. coli SHP3 appeared to be characterized by the nature of the aromatics to stress. Since E. coli SHP3 responded to 2,3-DHBP quite sensitively, this reporter strain could be applied for detecting some catecholic pollutants.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.1
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• pp.31-38
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• 2013

The degradation of 4-chlorophenol(4-CP) by various AOPs(Advanced Oxidation Processes) with continuous feeding of $H_2O_2$, including the ultraviolet/hydrogen peroxide, the Fenton and the photo-Fenton process has been investigated. The photo-Fenton process showed the highest removal efficiency for degradation of 4-chlorophenol than those of other AOPs including the Fenton process and the combined UV process with continuous feeding of $H_2O_2$. In the photo-Fenton process, the optimal experimental condition for 4-CP degradation was obtained at pH 3. Also the 4-CP removal efficiency increased with decreasing of the initial 4-CP concentration. 4-chlorocatechol and 4-chlororesorcinol were identified as photo-Fenton reaction intermediates, and the degradation pathways of 4-CP in the aqueous phase during the photo-Fenton reaction were proposed.

• Journal of Microbiology and Biotechnology
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• v.8 no.1
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• pp.96-100
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• 1998

Pseudomonas sp. S-47 degraded 4-chlorobenzoate (4CBA) to 4-chlorocatechol (4CC) that was subsequently ring-cleaved to form 5-chloro-2-hydroxymuconic semialdehyde. These intermediate compounds were identified by GC-mass spectrometry and UV-visible spectrophotometry. 5-chloro-2-hydroxymuconic acid converted from 5-chloro-2- hydroxymuconic semialdehyde (5C-2HMS) was dechlorinated to produce 2-hydroxypenta-2,4-dienoic acid (2HP-2,4DA) by the strain. These results indicate that Pseudomonas sp. S-47 degrades 4CBA to 2HP-2,4DA via a novel pathway including the meta-cleavage of 4CC and dechlorination of 5C-2HMS.

• Journal of Microbiology
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• v.35 no.3
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• pp.188-192
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• 1997

The strain of S-47 degrading 4-chlorobenzoic acid (4CBA) was isolated from Ulsan chemical industrial complex by enrichment cultivation with 1 mM 4CBA. The strain was Gram-negative rod and grew optimally at 30.deg.C and pH 7 under aerobic condition, so that the organism was identified as a species of Pseudomonas. Pseudomonas sp. S-47 degraded 4-chlorobenzoic acid to produce a yellow-colored meta-cleavage product, which was confirmed to be 5-chloro-2-hydroxymuconic semialdehyde (5C-2HMS) by UV-visible spectrophotometry. 5C-3HMS was proved trometry. This means that Pseudomonas sp. S-47 degraded 4CBA via 4-chlorocatechol to 5C-2HMS by meta-cleavage reaction and then to 5C-2HMA by 5C-2HMS dehydrogenase.

• Archives of Pharmacal Research
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• v.15 no.4
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• pp.360-364
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• 1992

Methylcatechol 2, 3-dioxygenase encoded in pWWO megaplasmid of Pseudomonas putida mt-2 has been cloned and overexpressed in Escherichia coli. This enzyme gene has been localized inside 2. 3-kb XhoI fragment derived from the pWWO megaplasmid. Analysis of enzyme activity and SDS-PAGE showed that the cloned methylcatechol 2, 3-dioxygenase gene in E. coli was about 100 fold overexpressed compared with the parental gene in P. putida mt-2 (pWWO). The cloned enzyme exhibited higher ring-fission activity to catechol than catechol derivatives including 3-methylcatechol, 4-methylcatechol, and 4-chlorocatechol.

• Korean Journal of Microbiology
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• v.36 no.1
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• pp.26-32
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• 2000

Catechol 2,3-dioxygenase was purified from recombinant strain E. coli CNU312 carrying the tomB gene which was cloned from toluene-degrading Burkholderia cepacia G4. The purification of this enzyme was performed by acetone precipitation, Sephadex G-75 chromatography, electrophoresis and electro-elution. The molecular weight of native enzyme was about 140.4 kDa and its subunit was estimated to be 35 kDa by SDS-PAGE. It means that this enzyme consists of four identical subunits. This enzyme was specifically active to catechol, and$K_(m)$ value and $V_(max)$value of this enzyme were 372.6 $\mu$M and 39.27 U/mg. This enzyme was weakly active to 3-methylcatechol, 4-methylcatechol, and 4-chlorocatechol, but rarely active to 2,3-DHBP. The optimal pH and temperature of the enzyme were pH 8.0 and $40^{\circ}C$. The enzyme was inhibited by $Co^(2+)$, $Mn^(2+)$, $Zn^(2+)$, $Fe^(2+)$, $Fe^(3+)$, and $Cu^(2+)$ ions, and was inactivated by adding the reagents such as N-bromosuccinimide, and $\rho$-diazobenzene sulfonic acid. The activity of catechol 2,3-dioxygenase was not stabilized by 10% concentration of organic solvents such as acetone, ethanol, isopropyl alcohol, ethyl acetate, and acetic acid, and by reducing agents such as 2-mercaptoethanol, dithiothreitol, and ascorbic acid. The enzyme was inactivated by the oxidizing agent $H_(2)$$O_(2)$, and by chelators such as EDTA, and ο-phenanthroline.

• Korean Journal of Microbiology
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• v.38 no.4
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• pp.275-275
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• 2002

Pseudomonas sp. S-47 is capable of catabolizing 4-chlorobenzoate (4CBA) as carbon and energy sources under aerobic conditions via the mesa-cleavage pathway. 4CBA-dioxygenase and 4CBA-dihydrodiol dehydrogenase (4CBA-DD) catalyzed the degradation af 4CBA to produce 4-chlorocatechol in the pathway. In this study, the xylL gene encoding 4CBA-DD was cloned from the chromosomal DNA of Pseudomonas sp. S-47 and its nucleotide sequence was analyzed. The xylL gene was found to be composed of 777 nucleotide pairs and to encode a polypeptide of 28 kDa with 258 amino acid residues. The deduced amino acid sequence of the dehydrogenase (XylL) from strain S-47 exhibited 98% and 60% homologies with these of the corresponding enzymes, Pseudomonas putida mt-2 (XyIL) and Acinetobacter calcoaceticus (BenD), respectively. However, the amino arid sequences show 30% or less homology with those of Pseudomonas putida (BnzE), Pseudomonas putida Fl (TodD), Pseudomonas pseudoalcaligenes KF707 (BphB), and Pseudomonas sp. C18 (NahB). Therefore, the 4CBA-dihydrodiol dehdrogenase of strain S-47 belongs to the group I dehydrogenase involved in the degradation of mono-aryls with a carboxyl group.