• 제목/요약/키워드: biphenyl degradation

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Roles of the meta- and the ortho-Cleavage Pathways for the Efficient Utilization of Aromatic Hydrocarbons by Sphingomonas yanoikuyae Bl

  • Jeongmin Song;Junghee Sung;Kim, Young-Min;Gerben J. Zylstra;Kim, Eungbin
    • Journal of Microbiology
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    • 제38권4호
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    • pp.245-249
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    • 2000
  • Catabolic pathways for the degradation of various aromatics by Sphingomonas yanoikuyae Bl are intertwined, joining at the level of substituted benzoates, which are further degraded vita ring cleavage reactions. The mutant strain EK497, which was constructed by deleting a large DNA region containing most of the genes for biphenyl, naphthalene, m-xylene, and m-toluate degradation, was unable to grow on all of the aromatics tested except for benzoate as the sole source of carbon and energy.S. yanoikuyae EK497 was found to possess only catechol ortho-ring cleavage activity due to deletion of the genes for the meta-cleavage pathway. Wild-type S. yanoikuyae Bl grown on benzoate has both catechol orthoand meta-cleavage activity. However, m-xylene and m-toluate, which are metabolized through methylbenzoate, and biphenyl, which is metabolized through benzoate, induce only the meta-cleavage pathway, suggesting the presence of a substrate-dependent induction mechanism.

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중위도 산림토양에서 분리한 부식질 분해능이 있는 Pseudomonas kribbensis CHA-19의 유전체 염기서열 초안 (Draft genome sequence of humic substances-degrading Pseudomonas kribbensis CHA-19 from temperate forest soil)

  • 김덕규;이형석
    • 미생물학회지
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    • 제55권2호
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    • pp.177-179
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    • 2019
  • 미국 뉴저지주 중위도 산림토양에서 부식산(천연 복합유기화합물인 부식질의 주요 구성성분) 분해능이 있는 세균 균주 Pseudomonas kribbensis CHA-19를 분리하였으며, 이후 또 다른 토양 유기물인 리그닌과 리그닌 유래의 페룰산(ferulic acid)과 바릴린산(vanillic acid)의 분해능을 확인하였다. 부식질 초기 저분자화 효소(예, dye-decolorizing peroxidase와 laccase-like multicopper oxidase)와 부식질 유래의 다양한 저분자 분해산물들을 분해하는 효소(예, vanillate O-demethylase와 biphenyl 2,3-dioxygenase)를 탐색하기 위해 CHA-19 게놈염기서열을 분석하였다. 최종 확보한 효소유전자 정보는 토양세균의 부식질 분해경로 제안에 사용되었다.

Isolation and Characterization of Pseudomonas sp. P2 Degrading Polychlorinated Biphenyls (PCBs)

  • Kim, Jung Ho;Sang Ki Choi;Moon Ki Park;Young Ho Kim;Seung Kyo Suh;Cheol Joo Woo;Heui Dong park
    • Journal of Microbiology and Biotechnology
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    • 제6권3호
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    • pp.167-172
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    • 1996
  • The bacterial strain P2 degrading polychlorinated biphenyls (PCBs) was isolated from the soil around the Shinchun stream in Taegu after enrichment culture in a media containing biphenyl as the sole carbon source. The isolate was identified as a strain of Pseudomonas sp. based on its morphological and physiological characteristics. The optimal conditions of initial pH of media and temperature for growth were 7.0 and $30^{\circ}C$, respectively. Degradation of biphenyl and PCBs was confirmed by GC during the culture of Pseudomonas sp. P2 in a media containing them at a concentration of 500 mg/I. It was observed that Pseudomonas sp. P2 could degrade 97.0$%$ of biphenyl and 60.0$%$ of PCBs after 160 h culture.

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Versatile Catabolic Properties of Tn4371-encoded bph Pathway in Comamonas testosteroni (Formerly Pseudomonas sp.) NCIMB 10643

  • Kim, Jong-Soo;Kim, Ji-Hyun;Ryu, Eun-Kyeong;Kim, Jin-Kyoo;Kim, Chi-Kyung;Hwang, In-Gyu;Lee, Kyoung
    • Journal of Microbiology and Biotechnology
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    • 제14권2호
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    • pp.302-311
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    • 2004
  • Comamonas testosteroni (formerly Pseudomonas sp.) NCIMB 10643 can grow on biphenyl and alkylbenzenes $(C_2-C_7)$ via 3-substituted catechols. Thus, to identify the genes encoding the degradation, transposon-mutagenesis was carried out using pAG408, a promoter-probe mini-transposon with a green fluorescent protein (GFP), as a reporter. A mutant, NT-1, which was unable to grow on alkylbenzenes and biphenyl, accumulated catechols and exhibited an enhanced expression of GFP upon exposure to these substrates, indicating that the gfp had been inserted in a gene encoding a broad substrate range catechol 2,3-dioxygenase. The genes (2,826 bp) flanking the gfp cloned from an SphI-digested fragment contained three complete open reading frames that were designated bphCDorfl. The deduced amino acid sequences of bphCDorfl were identical to 2,3-dihydroxybiphenyl 1,2-dioxygenase (BphC), 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate hydrolase (BphD), and OrfI, respectively, that are all involved in the degradation of biphenyl/4-chlorobiphenyl (bph) by Ralstonia oxalatica A5. The deduced amino acid sequence of the orfl revealed a similarity to those of outer membrane proteins belonging to the OmpW family. The introduction of the bphCDorfl genes enabled the NT-l mutant to grow on aromatic hydrocarbons. In addition, PCR analysis indicated that the DNA sequence and gene organization of the bph operon were closely related to those in the bph operon from Tn4371 identified in strain A5. Furthermore, strain A5 was also able to grow on a similar set of alkylbenzenes as strain NCIMB 10643, demonstrating that, among the identified aromatic hydrocarbon degradation pathways, the bph degradation pathway related to Tn4371 was the most versatile in catabolizing a variety of aromatic hydrocarbons of mono- and bicyclic benzenes.

pKT230 벡터를 이용한 Pseudomonas sp. P20의 2,3-Dihydroxybiphenyl Dioxygenase 유전자의 클로닝

  • 김지영;김치경;가종억;민경희;박용근
    • 한국미생물·생명공학회지
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    • 제24권6호
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    • pp.657-663
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    • 1996
  • Pseudomonas sp. P20 isolated from the polluted environment is capable of degrading biphenyl and 4-chlorobiphenyl. The pcbABCD genes responsible for degradation of biphenyl and 4-chlorobiphenyl were cloned using pBluescript SK(+) from the chromosomal DNA of Pseudomonas sp. P20 to construct pCK1 and pCK102, harbouring pcbABCD and pcbCD, respectively. The 2, 3-DHBP dioxygenase gene, pcbC, was cloned again from pCK102 by using pKT230 which is known as a shuttle vector and pKK1 hybrid plasmid was constructed. The E. coli KK1 transformant obtained by transforming the pKK1 into E. coli XL1-Blue showed 2, 3-DHBP dioxygenase activity. The specific 2, 3-DHBP dioxygenase activity of E. coli KK1 was similar to that of the E. coli CK102, but much higher than those of the natural isolates, Pseudomonas sp. DJ-12 and Pseudomonas sp. P20.

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Pseudomonas sp. DJ-12 pcbAB 유전자의 Escherichia coli에서의 클로닝 및 발현 (Cloning and Expression of pcbAB Genes from Pseudomonas sp. DJ-12 in Escherichia coli)

  • 한재진;성태경;김치경
    • 미생물학회지
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    • 제31권2호
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    • pp.129-134
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    • 1993
  • 4-Chlorobiphenyl(4CB) 과 biphenyl 을 분해하는 Pseudomoas sp. DJ-12 의 pcbAB 는 분해초기 단계에 작용하는 4-chlorobiphenyl dioxygenase 와 dihydrodiol dehydrogenase 효소를 생산하는 유전자들이다. 이 유전자를 E. coli XL1-Blue 에 플로닝하여 CU101 형질전환체를 얻었다. CU101 의 pCU101 재조합 plasmid 에 클로닝된 pcbAB 유전자는 크기가 약 2.2 kb 이고 3 개의 Hind III 제한효소 위치가 있었으며, 독자적인 promoter 를 가지고 있었다. CU101 에 대하여 biphenyl 을 기질로 하여 생성된 대사산물을 resting cell assay 를 한 결과 2, 3-dihydroxybiphenyl 이 검출되어 pcbAB 유전자들이 E. coli 에서 잔 발현된다는 것을 의미하였다. 그러나 dechlorination 작용은 pcbAB 유전자와 관계없이 4AB 의 개환과정 후 생성된 4-chlorobenzoate 에서 일어나는 것으로 해석된다.

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Biodegradation of Phenanthrene by Sphingomonsa sp. Strain KH3-2

  • Shin, Su-Kyuong;Oh, Young-Sook;Kim, Sang-Jin
    • Journal of Microbiology
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    • 제37권4호
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    • pp.185-192
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    • 1999
  • A phenanthrene-degrading bacterium was isolated from an oil-spilled intertidal sediment sample and identified as Sphingomonas sp. KH3-2. The strain degraded polycyclic aromatic compounds such naphthalene, fluorene, biphenyl, and dibenzothiophene. When strain KH3-2 was cultured for 28 days at 25C, a total of 500 ppm of phenanthrene was degrated with a concomitant production of biomass and Folin-Ciocalteau reactive aromatic intermediates. Analysis of intermediates during phenanthrene degradation using high-performance liquid chromatography and gas chromatography/mass spectrometry indicated that Sphingomonas sp. KH3-2 primarily degrades phenanthrene to 1-hydroxy-2-naphthoic acid (1H2NA) and further metabolizes 1H2NA through the degradation pathway of naphthalene.

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PCBs의 광화학적 연구: NaOH 및 휴믹산 (humic acid, HA)에 의한 분해특성 (Effects of NaOH and Humic Acid on the UV Photolysis of PCBs)

  • 신혜승;김재현
    • 한국환경보건학회지
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    • 제40권2호
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    • pp.147-156
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    • 2014
  • Objectives: This study was carried out to examine whether the apparent photolysis with or without sensitizers [NaOH and humic acid (HA)] was prompted photodegradation of polychlorinated biphenyl (PCB) in aqueous solution. Methods: PCBs photodegradation occurred using fluorescence black lamps at ${\lambda}_{max}=300nm$. PCB congeners were exposed in 10 ppm HA or 0.05N NaOH solutions, to investigate the decreasing profile of PCB concentration with time. The PCBs were then analyzed by gas chromatography/mass spectrometry (GC-MS). Reductive degradation profile of PCB congeners in the presence of both sensitizers under oxygen-saturated protic conditions was described using the wind-rose diagrams. Results: Use of HA or NaOH decreased PCB concentration with time in the dark and on irradiation, indicating that photolysis underwent through reductive dechlorination through energy transfer and possibly with reactive oxygens. The dechlorination was marked by a chromatographic shift, observed in the GC-MS plots. Therefore it is logical to assume that increasing the dose of sensitizers would increase the photodegradation rates of PCBs. The half-lives of pentachloro-PCB (penta-3) in 0.05N NaOH and 10 ppm HA were estimated at about 47 hours and 39 hours, respectively, under the same experimental conditions of photolysis. It was found that the rate of photolysis of pentachloro-PCB in aqueous solution followed apparent first-order kinetics compared to other congeners. Conclusion: Photochemical degradation (using 328 nm UV light) of penta- and hexa-PCBs in HA or alkaline solution is a viable method for pretreatment method. The results are helpful for the further comprehension of the reaction mechanism for photolytic dechlorination of PCBs in aquatic system.

Isolation and Characterization of Comprehensive Polychlorinated Biphenyl-Degrading Bacterium, Enterobacter sp. LY402

  • Jia, Ling-Yun;Zheng, Ai-Ping;Xu, Li;Huang, Xiao-Dong;Zhang, Qing;Yang, Feng-Lin
    • Journal of Microbiology and Biotechnology
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    • 제18권5호
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    • pp.952-957
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    • 2008
  • A Gram-negative bacterium, named LY402, was isolated from contaminated soil. 16S rDNA sequencing and measurement of the physiological and biochemical characteristics identified it as belonging to the genus Enterohacter. Degradation experiments showed that LY402 had the ability to aerobically transform 79 of the 91 major congeners of Aroclor 1242, 1254, and 1260. However, more interestingly, the strain readily degraded certain highly chlorinated and recalcitrant polychlorinated biphenyls (PCBs). Almost all the tri- and tetra-chlorobiphenyls (CBs), except for 3,4,3',4'-CB, were degraded in 3 days, whereas 73% of 3,4,3',4'-, 92% of the penta-, 76% of the hexa-, and 37% of the hepta-CBs were transformed after 6 days. In addition, among 12 octa-CBs, 2,2',3,3',5,5',6,6-CB was obviously degraded, and 2,2',3,3',4,5,6,6'- and 2,2',3,3',4,5,5',6'-CB were slightly transformed. In a metabolite analysis, mono- and dichlorobenzoic acids (CBAs) were identified, and parts of them were also transformed by strain LY402. Analysis of PCB degradation indicated that strain LY402 could effectively degrade PCB congeners with chlorine substitutions in both ortho- and para-positions. Consequently, this is the first report of an Enterobacteria that can efficiently degrade both low and highly chlorinated PCBs under aerobic conditions.

Purification and Characterization of 2,3-Dihydroxybiphenyl 1,2-Dioxygenase from Comamonas sp. SMN4

  • Lee, Na-Ri;Lee, Jang-Mi;Min, Kyung-Hee;Kwon, Dae-Young
    • Journal of Microbiology and Biotechnology
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    • 제13권4호
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    • pp.487-494
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    • 2003
  • 2,3-Dihydroxybiphenyl 1,2-dioxygenase (23DBDO), an enzyme of the biphenyl biodegradation pathway encoded by the bphC gene of Comnmonas sp. SMN4, was expressed and purified using column chromatographies. SDS-PAGE of purified 23DBDO showed a single band with a molecular mass of 32 kDa, which was consistent with the data from the gel filtration chromatography (GFC). The purified enzyme exhibited a maximum 23DBDO activity at pH 9.0 and was stable at pH 8.0. The enzyme showed maximum activity at $40^{\circ}C$ and maintained activity at $30^{\circ}C$ for 24 h. Kinetic parameters represented by Michaelis-Menten constants such as $K_m\;and\;V_{max}$ values for various substrates were determined by Lineweaver-Burk plots: The purified enzyme 23DBDO from Comamonas sp. SMN4 had the highest catalytic activity for 2,3-dihydroxybiphenyl and 3-methylcatechol, and had very poor activity with catechol and 4-methylcatechol.