• Journal of Microbiology and Biotechnology
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• 제28권2호
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• pp.330-337
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• 2018

Polycyclic aromatic hydrocarbons (PAHs), including naphthalene, are widely distributed in nature. Naphthalene has been regarded as a model PAH compound for investigating the mechanisms of bacterial PAH biodegradation. Pseudomonas sp. AS1 isolated from an arseniccontaminated site is capable of growing on various aromatic compounds such as naphthalene, salicylate, and catechol, but not on gentisate. The genome of strain AS1 consists of a 6,126,864 bp circular chromosome and the 81,841 bp circular plasmid pAS1. Pseudomonas sp. AS1 has multiple dioxygenases and related enzymes involved in the degradation of aromatic compounds, which might contribute to the metabolic versatility of this isolate. The pAS1 plasmid exhibits extremely high similarity in size and sequences to the well-known naphthalene-degrading plasmid pDTG1 in Pseudomonas putida strain NCIB 9816-4. Two gene clusters involved in the naphthalene degradation pathway were identified on pAS1. The expression of several nah genes on the plasmid was upregulated by more than 2-fold when naphthalene was used as a sole carbon source. Strains have been isolated at different times and places with different characteristics, but similar genes involved in the degradation of aromatic compounds have been identified on their plasmids, which suggests that the transmissibility of the plasmids might play an important role in the adaptation of the microorganisms to mineralize the compounds.

• Journal of Microbiology and Biotechnology
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• 제16권11호
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• pp.1819-1825
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• 2006

Four naphthalene-degrading bacteria (Pseudomonas sp. strains O1, W1, As1, and G1) were isolated feom pollutant-contaminated sites. Examination of their substrate utilization and analyses of key naphthalene-catabolic regulatory genes revealed that the pathway and regulation of naphthalene-degradation in all four strains resemble those of NAH7 from P. putida G7. Superoxide anion production, superoxide dismutase activity, and catalase activity during their growth on naphthalene-amended medium increased significantly, compared with those with glucose-amended medium. Addition of ascorbate, an antioxidant, or ferrous iron ($Fe^{2+}$) increased the growth rates of all tested microorganisms on naphthalene. Northern blot and HPLC analyses showed that both nahA gene expression and naphthalene degradation increased under those conditions. Our data suggest that naphthalene degradation can impose severe oxidative stress, and defenses against oxidative stress would play an important role in the metabolism of naphthalene.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.89-91
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• 2000

Polynuclear aromatic hydrocarbon (PAH) compounds are highly carcinogenic chemicals and common groundwater contaminants that are observed to persist in soils. The adherence and slow release of PAHs in soil is an obstacle to remediation and complicates the assessment of cleanup standards and risks. Biological degradation of PAHs in soil has been an area of active research because biological treatment may be less costly than conventional pumping technologies or excavation and thermal treatment. Biological degradation also offers the advantage to transform PAHs into non-toxic products such as biomass and carbon dioxide. Ample evidence exists for aerobic biodegradation of PAHs and many bacteria capable of degrading PAHs have been isolated and characterized. However, the microbial degradation of PAHs in sediments is impaired due to the anaerobic conditions that result from the typically high oxygen demand of the organic material present in the soil, the low solubility of oxygen in water, and the slow mass transfer of oxygen from overlying water to the soil environment. For these reasons, anaerobic microbial degradation technologies could help alleviate sediment PAH contamination and offer significant advantages for cost-efficient in-situ treatment. But very little is known about the potential for anaerobic degradation of PAHs in field soils. The objectives of this research were to assess: (1) the potential for biodegradation of PAH in field aged soils under denitrification conditions, (2) to assess the potential for biodegradation of naphthalene in soil microcosms under denitrifying conditions, and (3) to assess for the existence of microorganisms in field sediments capable of degrading naphthalene via denitrification. Two kinds of soils were used in this research: Harbor Point sediment (HPS-2) and Milwaukee Harbor sediment (MHS). Results presented in this seminar indicate possible degradation of PAHs in soil under denitrifying conditions. During the two months of anaerobic degradation, total PAH removal was modest probably due to both the low availability of the PAHs and competition with other more easily degradable sources of carbon in the sediments. For both Harbor Point sediment (HPS-2) and Milwaukee Harbor sediment (MHS), PAH reduction was confined to 3- and 4-ring PAHs. Comparing PAH reductions during two months of aerobic and anaerobic biotreatment of MHS, it was found that extent of PAHreduction for anaerobic treatment was compatible with that for aerobic treatment. Interestingly, removal of PAHs from sediment particle classes (by size and density) followed similar trends for aerobic and anaerobic treatment of MHS. The majority of the PAHs removed during biotreatment came from the clay/silt fraction. In an earlier study it was shown that PAHs associated with the clay/silt fraction in MHS were more available than PAHs associated with coal-derived fraction. Therefore, although total PAH reductions were small, the removal of PAHs from the more easily available sediment fraction (clay/silt) may result in a significant environmental benefit owing to a reduction in total PAH bioavailability. By using naphthalene as a model PAH compound, biodegradation of naphthalene under denitrifying condition was assessed in microcosms containing MHS. Naphthalene spiked into MHS was degraded below detection limit within 20 days with the accompanying reduction of nitrate. With repeated addition of naphthalene and nitrate, naphthalene degradation under nitrate reducing conditions was stable over one month. Nitrite, one of the intermediates of denitrification was detected during the incubation. Also the denitrification activity of the enrichment culture from MHS slurries was verified by monitoring the production of nitrogen gas in solid fluorescence denitrification medium. Microorganisms capable of degrading naphthalene via denitrification were isolated from this enrichment culture.

• 한국지하수토양환경학회지:지하수토양환경
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• 제14권6호
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• pp.45-52
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• 2009

나프탈렌 분해균주인 Pseudomonas aeruginosa CZ6을 오염된 토양에서 분리하였으며 분리된 균주는 결정상태의 나프탈렌에 부착하고 그 주변에 extracellular polymeric substance를 분비하는 특성을 가졌다. LB, YM과 MSM 배지를 사용하여 배지의 종류에 따른 biofilm 생성량을 측정한 결과, LB 배지에서 biofilm이 가장 많이 생성되는 것으로 나타났다. 나프탈렌을 기질로 한 배양조건에서 균주는 기질의 농도 영향을 크게 받지 않고 0.10% 기질, 150 rpm 조건에서 최적 배양조건은 $30^{\circ}C$, pH 7로 나타났다. 두 가지 토양에서 배지의 종류에 따른 나프탈렌의 분해특성을 관찰한 결과 초기에는 MSM 배지에서 나프탈렌이 가장 많이 분해가 되었다. 그러나 생물이용성이 제한을 받는 조건에서 LB 배지의 나프탈렌이 가장 빨리 제거가 되었다. 이런 결과는 biofilm의 형성과 extracellular polymeric substance 생성이 토양에 흡착된 잔류 나프탈렌의 생물학적 이용성을 향상시키기 때문인 것으로 사료된다.

• Journal of Applied Biological Chemistry
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• 제50권2호
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• pp.41-45
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• 2007

Polaromonas naphthalenivorans CJ2, responsible for naphthalene degradation at a coal tar contaminated site, was isolated on MSB agar media supplied with naphthalene vapor as the sole carbon source at $10^{\circ}C$. The strain is not isolated under the same isolation condition using the same soil sediment at $20^{\circ}C$ although its optimum temperature is about $20^{\circ}C$. In this work we explored the reason why strain CJ2 could not have been isolated on MSB agar with naphthalene vapor at $20^{\circ}C$. Dispersed CJ2 cells in PBS buffer formed colonies on MSB agar with naphthalene vapor at $10^{\circ}C$ with low naphthalene vapor pressure, but not at $20^{\circ}C$ with high naphthalene vapor pressure. However, streaked cells without resuspension grew on MSB agar with naphthalene vapor at $10^{\circ}C,\;20^{\circ}C$, and even $25^{\circ}C$. Investigation of scanning electron microscopy showed that CJ2 cells formed extracellular polysaccharide (EPS) capsules, which were released easily from CJ2 cells by just dispersion. Therefore, it is concluded that strain CJ2 is able to overcome the naphthalene toxicity by forming a capsule-type barrier around the cells although it is susceptible to naphthalene toxicity at high temperature.

• 한국미생물·생명공학회지
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• 제16권3호
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• pp.199-204
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• 1988

Naphthalene을 유일한 탄소원으로 이용하는 균을 분식 배양과 연속식 배양에 의해서 토양과 폐수로부터 분리하였다. 이 균은 Pseudomonas putida로 동정되었으며, 최적 pH와 온도는 각각 7.0과 3$0^{\circ}C$ 이었다. 분리된 균은 1,5-dihydroxynaphthalene을 naphthalene보다 더욱 잘 이용하였으며 benzoate와 salicylate도 이용하였다. 또한 catechol dl meta-분해경로를 통해서 분해되었으며, ampicillin, chloramphenicol, kanamycin, streptomycin에 대해서 강한 저항성을 지니고 있었으며, naphthalene의 분해에 관여하는 약 110kb 크기의 plasmid를 1개 지니고 있었다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.177-181
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• 2000

A lab-scale slurry reactor was developed for the treatment of contaminated sediments with polycyclic aromatic hydrocarbons (naphthalene, phenanthrene). In this system, range from 85 to 95% of PAHs with 2~3 rings were degraded within 11 days. Higher naphthalene degradation(94.05%) over phenanthrene degradation(87.07%) was probably due its higher solubility. Both compounds were not detected in aqueous phase after 7days and only 26.8% of naphthalene and 49.1% of phenanthrene were biodegraded. Removal TPH(Total Petroleum Hydrocarbon) concentration in solid after 11 days of treatment was 46%.

• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.270-273
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• 1994

Pseudomonas putida 3SK, which was constructed by the conjugal transfet of the $CAM::TOL^{*}$ plasmid of Pseudomonas putida CSnA and the NAH plasmid of Pseudomonas putida KCTC 2403 into n-alkane assimilating Pseudomonas putida KCTC 2405, showed a broad degradation spectrum and floc-forming ability. This strain degraded m-toluic acid, naphthalene, camphor and decane simultaneously. $Hg^{2+}$ at the concentration of 1 ppm in the minimal medium could not inhibit the growth of this strain. The degradation of m-toluic acid by Pseudomonas putida 3SK was not repressed by the easily utilizable compounds, such as glucose and succinate. But, the addition of formalin inhibited the growth of Pseudomonas putida 3SK. After the cultivation of this strain on the artificial wastewater containing m-toluic acid, naphthalene, camphor and decane for 24 hr, the initial COD value (1500) of the artificial wastewater was declined to 300.

• 한국미생물·생명공학회지
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• 제22권4호
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• pp.423-429
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• 1994

A bacterial strain which formed a distinct colony on agar plate containing naphthalene as a vapor phase and grew well ina liquid minimal medium was isolated and identified as Alcaligenes sp. A111. Optimum temperature and pH for the cultivation of Alcaligenes sp. A111 were 30$\cir$C and 7.0, respectively. Cell growth increased dramatically from 12 hours after inoculation and revealed a stationary phase at about 48 hours. Relative growth rate ($\mu$')increased hyperbolically depending on the conceration of naphthalene up to 500 ppm and reached to the maximum value pf 2.8/day, but $\mu$' didn't change within a range of 500~4000 ppm naphthalene. NH$_{4}$Cl or NH$_{4}$NO$_{3}$ was preferrd as a nitrogen source and a P : N ratio by weight og 6 : 1 was favorable to cell growth. Alcaligenes sp. A111 utilized the intermediates of degradation of naphthalene and showed tolerance to benzene, toluene, and octane. therefore, it is suggested that Alcaligenes sp. A111 could be effectively used for the biological treatment of wastewater containing naphthalene in the presence of some aromatic compounds.

• 생명과학회지
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• 제9권1호
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• pp.84-91
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• 1999

폐기름 유출지역에서 분리 동정된 미생물 Xl, X2, X3은 폐유나 그 주성분인 난분해성 물질들을 유일 탄소원으로 자랄 수 있었다. Naphthalene과 2-methyl naphthalene은 7일만에 약 80$\%$ 분해되었다. Hexane과 hexadecane은 거의 대부분 분해되며 60$\%$의 분해가 폐유에서 관찰되었다. 합성 계면활성제인 Triton X-100와 Tween 20은 세포의 성장과 분해에 오히려 저해함을 보였다. Xl, X2은 그람 음성을 X3은 그람 양성을 보이며 항생제 ampicillin에 저항성을 가진다. Xl의 30kb plasmid을 E.coli에 transform하여 유전공학적 활용 가능성을 보였다.