• Journal of Microbiology
• /
• 제35권1호
• /
• pp.53-60
• /
• 1997

Pseudomonas sp. P20 and Pseudomonas sp. DJ-12 isolated from the polluted environment are capable of degrading biphenyl and 4-chlorobiphenyl (4CB) to produce benzoic acid and 4-chlorobenzoic acid (4CBA) respectively, by pcbABCD-encoded enzymes. 4CBA can be further degraded by Pseudomonas sp. DJ-12, but not by Pseudomonas sp P20. However, the meta-cleavage activities of 2, 3-dihydroxybiphenyl (2, 3-DHBP) and 4-chloro-2, 3-DHBP dioxygenases (2, 3-DHBD) encoded by pcbC in Pseudomonas sp. P20 were stronger than Pseudomonas sp. DJ-12. In this study, the pcbC gene encoding 2, 3-DHBD was cloned from the genomic DNA of Pseudomonas sp. P20 by using pKT230. A hybrid plasmid pKK1 was constructed and E. coli KK1 transformant was selected by transforming the pKK1 hybrid plasmid carrying pcbC into E. coli XL1-Blue. By transferring the pKK1 plasmide of E. coli KK1 into Pseudomonas sp. DJ-12 by conjugation, a recombinant strain Pseudomonas sp. P20, Pseudomonas sp. DJ-12, and the recombinant cell assay methods. Pseudomonas sp. DJ12-C readily degraded 4CB and 2, 3-DHBP to produce 2-hydroxy-6-oxo-6-phenylhexa-2, 4-dienoic acid (HOPDA), and the resulting 4CBA and benzoic acid were continuously catabolized. Pseudomonas sp. DJ12-C degraded 1 mM 4CB completely after incubation for 20 h, but Pseudomonas sp. P20 and Pseudomonas sp. DJ-12 showed only 90% and Pseudomonas sp. DJ-12 had, but its degradation activity to 2, 3-DHBP, 3-methylcatechol, and catechol was improved.

• Journal of Microbiology
• /
• 제35권4호
• /
• pp.290-294
• /
• 1997

4-Chlorobiphenyl-degrading Pseudomonas sp. DJ-12 was able to degrade 4-chlorobenzoate(4CBA), 4-iodobenzoate, and 4-bromobenzoate completely under aerobic conditions. During. the degradation of 4CBA by Pseudomonas sp. DJ-12, chloride ions were released by dechlorination and 4-hydroxybenzoate was produced as an intermediate metabolite. The NotI-KNA fragments of pKC157 containing dechlorination genes hybridized with the gene encoding 4CBA:CoA dehalogenase of Pseudomonas sp. CBS3 which is responsible for the hydrolytic dechlorination of 4CBA. These results imply that Pseudomonas sp. DJ-12 degrades 4CBA to 40hydroxybenzoate via dechlorination as the initial step of its degradativ pathway. The genes responsible for dechlorination of 4CBA were found to be blcated on the chromosomal DNA of Pseudomonas sp. DJ-12.

• 미생물학회지
• /
• 제40권2호
• /
• pp.121-126
• /
• 2004

4-chlorobiphenyl (4CB)의 분해균주인 Pseudomonas sp. strain DJ-12의 16S rDNA의 염기서열을 분석한 결과 Comamonas sp. strain DJ-12로 재분류 되었다. Pseudomonas sp. strain DJ-12로부터 4CB의 분해결과 생성되는 2,3-dihydroxybiphenyl을 계속 분해하는데 관여하는 pcbC1Dl 유전자를 이미 보고된 바 있다. 이번 연구에서는 Comamonas sp. strain DJ-12로부터 4CB 분해에 관여하는 pcbABC2D2 유전자를 클로닝하여 염기서열을 분석하였다. PcbAB 및 pcbCD 유전자들의 염기서열은 48, 65％, 추정 아미노산 서열은 33, 42％의 낮은 유사도를 보였다. 본 연구에서 얻어진 pcbC2D2 유전자는 이미 보고만 pcbCIDl 유전자와 염기의 개수와 서열의 유사도가 서로 다름을 보여 주었다. Comamonas sp. strain DJ-12의 두 가지 pcbCD유전자들은 Southern hybridization 결과에서도 유사성을 보이지 않았으며, 서로 다른 위치에 존재함을 보여주었다. 그러나 2,3-dihydroxybiphenyl의 분해 특성은 동일하였다. 이와 같은 결과는 Comamonas sp. strain DJ-12 균주가 2조의 pcbCD 유전자를 가지고 있다는 것을 의미하는 것이다.

• 미생물학회지
• /
• 제32권2호
• /
• pp.126-131
• /
• 1994

4-Chlorobiphebyl(4CB)를 분해한 Pseudomonas sp. DJ-12가 가지고 있는 pcbABCD 유전자를 Escherichia coli에 클로닝한 결과, 재조합 균주인 E. coli CU1과 CU101은 모두 Pseudomonas sp. DJ-12에서와 같이 4CB를 분해하여 2,3-dihydrozybiphenyl(2,3-DHBP)을 생성하는 탈염소화 기능을 보여주었다. 특히 pcbAB를 포함하는 재조합 플라스미드인 pCU101을 가지고 있는 E. coli CU101은 Pserudomonas sp. DJ-12에서와 같이 4CB로부터 4-chlorobenzoic acid를 생성하지 않고 2, 3-DHBP만을 생성하는 탈염소화 기능을 보여주었다. 그러므로 Pseudomonas sp. DJ-12의 염색체 DNA로부터 클로닝한 약 2.2kb의 pcbAB 유전자는 4CB로부터 2,3-DHBP만을 생성하는 탈염소화기능을 가지고 있음이 밝혀졌다.

• Journal of Microbiology and Biotechnology
• /
• 제12권3호
• /
• pp.417-422
• /
• 2002

Gene fusions were constructed by the transcriptional fusion of the dnaK promoter of pseudomonas sp. DJ-12 or E. coli to the lux or luc marker gene. The dnaKp-DJ::luxCDABE bioluminescent fusion in the biosensor using the Pseudomonas sp. DJ-12 dnaK promoter exhibited about 5-fold more extensive response to ethanol than that of dnaKp-EC::luxCDABE. The bioluminescent response of the dnaK-DJ::luc fusion to ethanol was much weaker than those of the other fusions. The biosensor harboring the dnaKp-DJ::luCDABE fusion was examined for its bioluminescence production based on exposure to aromatic compounds, such as biphenyl, 4-chlorobiphenyl (4CB), 4-hydroxybenzoate (4HBA), and catechol. In particular, the bioluminescence produced by the dnaKp-DJ::luxCDABE fusion was most sensitive to 1 mM biphenyl and 4CB when exposed for 80 min, and the responses were also very strong to other aromatics. Therefore, the biosensor bearing the dnaKp-DJ::luxCDABE fusion would appear to be the most useful for the detection of aromatics and other pollutants.

• Journal of Microbiology and Biotechnology
• /
• 제8권6호
• /
• pp.692-695
• /
• 1998

Pseudomonas sp. DJ-12 was able to degrade 4-chlorobenzoate by hydrolytic dechlorination to produce 4-hydroxybenzoate and chloride ion. The fcbABC genes responsible for the hydrolytic dechlorination were cloned from the chromosomal DNA of the organism. The genes were found to be organized in the order fcbB-fcbA-fcbC, but there was an intergenic space between the fcbA and fcbC genes.

• Journal of Microbiology
• /
• 제37권3호
• /
• pp.123-127
• /
• 1999

A Pseudomonas sp. strain DJ-12 isolated by 4-cholrobiphenyl enrichment culture technique is capable of utilizing 4-hydroxybenzoic acid as a sole source of carbon and energy. The bacterium catabolized 4-hydroxybenzoic acid through the intermediate formation of protocatechuic acid, which was further metabolized. The cell free extracts of pseudomonas sp. DJ-12, grown on 4-hydroxybenzoic acid showed higher activities of 4-hydroxyenzoate 3-hydroxylase and protocatechuate 4,5-dioxygenase, but the activity of catechnol 2,3-dioxygenase was lower. The results suggest that 4-hydroxybenzoic acid is catabolized via protocatechuic acid rather than catechol or gentisic acid in this bacterium and that the protocatechuic acid formed was metabolized through a metacleavage pathway by protocatechuate 4,5-dioxygenase.

• 한국미생물·생명공학회지
• /
• 제21권2호
• /
• pp.150-156
• /
• 1993

The 2,3-dihydroxybiphenyl(2,3-DHBP) dioxygenase, the product of pcbC gene, was purified from the biphenyl and 4-chlorobiphenyl degrading Pseudomonas sp. DJ-12 by the methods of acetone precipitation, DEAE-Sephadex A-50 ion exchange chromatography, and Sephadex G-150 gel filtration chromatography. The enzyme was estimated to be about 260 kilodaltons in molecular weight and to be consisted of eight subunits. The Km value of the enzyme was 61 nM to 2,3-DHBP and the highest activity of the enzyme was observed at pH 8 and 30C.

• 미생물학회지
• /
• 제35권2호
• /
• pp.139-145
• /
• 1999

방향족 탄화수소 화학물질들은 자연계에 오염되면 미생물에 의한 분해가 미미하여 장기 축적됨으로써 생명체에 독성을 나타낸다. 이러한 방향족 탄화수소가 준치사 수준의 농도로 미생물에 노출되면 stress-shock 단백질을 합성하거나 세포 구성물질에 생화학적 변화가 일어나 적응현상이 나타나게 된다. 본 연구에서는 Pseudomonas sp. DJ-12를 여러 가지 농도의 catechol 로 처리했을 때 나타나는 stress-shock 단백질의 합성양상과 함께 세포의 형태와 생존을 위한 내성의 변화를 연구하였다. Pseudomonas sp. DJ-12는 0.5~1mM 의 catechol 이 6시간 배양 후 60% 이상이 분해되었으나, 3mM 도는 그 이상의 농도에서는 전혀 분해되지 않앗고 생존 세포수는 30시간 처리 했을 때부터 \10^2$ cell/ml 또는 그 이상이 사멸되었다. DnaK는 1mM 이상의 catechol 로 10분간 처리할 때 유도 생성되었고, GroEL은 0.5 mM 이상에서 생성되었다. 10mM 의 catechol로 처리한 Pseudomonas sp. DJ-12 의 세포는 세포벽에 구멍이 생겼으며 간균의 형태가 일그러지는 변화가 관찰되었다. 준치사 농도인 1mM의 catechol 이나 benzoate 또는 4-chlorobenzoate 로 전처리한 Pseudomonas sp. DJ-12는 stress-shock 단백질이 합성되었을 뿐 아니라, 치사 농도인 10mM 의 catechol에서 tolerance를 나타내었다.

• Journal of Microbiology and Biotechnology
• /
• 제9권4호
• /
• pp.422-428
• /
• 1999

Aromatic hydrocarbons can be utilized as carbon and energy sources by some microorganisms at lower concentrations. However, they can also act as stresses to these organisms at higher concentrations. Pseudomonas sp. DJ-12 is capable of degrading 0.5 mM concentration of benzoate and 4-chlorobenzoate (4CBA). In this study, the exposure of Pseudomonas sp. DJ-12 to the pollutant stresses of benzoate and 4CBA at various concentrations was comparatively studied for its cellular responses, including survival tolerance, degradability of the aromatics, and morphological changes. Pseudomonas sp. DJ-12 utilized 0.5 to 1.0mM benzoate and 4CBA as carbon and energy sources for growth. However, the organism could not degrade the aromatics at concentrations of 3 mM or higher, resulting in reduced cell viability due to the destruction of the cell envelopes. Pseudomonas sp. DJ-12 cells produced stress-shock proteins such as DnaK and GroEL when treated with benzoate and 4CBA at concentrations of 0.5mM, or higher as sublethal dosage; Yet, there were differing responses between the cells treated with either benzoate or 4CBA. 4CBA affected the degradability of the cells more critically than benzoate. The DnaK and GroEL stress-shock proteins were produced either by 1mM benzoate with 5 min treatment or by higher concentrations after 10min. The proteins were also induced by 0.5mM 4CBA, however, it needed at least 20min treatment or longer. These results indicate that the chlorination of benzoate increased the recalcitrance of the pollutant aromatics and changed the conditions to lower concentrations and longer treatment times for the production of stress-shock proteins. of stress-shock proteins produced by the aromatics at sublethal concentrations functioned interactively between the aromatics for survival tolerance to lethal concentrations.