• Journal of Microbiology and Biotechnology
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• v.4 no.4
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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.

• Korean Journal of Microbiology
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• v.28 no.1
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• pp.71-75
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• 1990

The isolates biodigrading crude oil were examined to characterize thier properties. Isolates which were identified as Acinetobacter lwoffii G1, Klebsiella pneumoniae L25, Pseudomonas maltophilia N246, Xanthomonas campestris M12, and Xanthomonas sp. M28. The optimum concentration of crude oil was 0.15% for the bacterial growth. X. campestris M12, Xanthomonas sp. M28, and K. penumoniae L25 showed the maximal growth at the concentration of 3.5% sodium chloride, indicating that they were derived from sea water. Among the isolates, X. campestris M12, Xanthomonas sp. M28 specially utilized hexadecane and octane, and P. maltophilia N246 utilized octane with optimum concentration of 0.2-0.3% as sole carbon source. The utilization of components of saturate fraction by K. pneumoniae L25 was examined by gas-liquid chromatography. The short-chain saturates are used before the long chain ones although they almost disappear within 8 days of incubation at $30^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• v.11 no.1
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• pp.56-60
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• 2001

A kerosene fungus of Cladosporium resinae NK-1 was examined for its ability to degrade individual n-alkanes and aromatic hydrocarbons by gas chromatography-mass spectrometry, and its organic solvent-tolerance was investigated by making use of the water-organic solvent suspension culture method. It grew on a wide range of solvents of varying hydrophobicities and it was found to have tolerance to various kinds of toxic organic solvents (10%, v/v) such as n-alkanes, cyclohexane, xylene, styrene, and toluene. A hydrocarbon degradation experiment indicated that NK-1 had a greater n-alkane degrading ability compared to that of the other selected strains. C. resinae NK-1, which could utilize 8-16 carbon chain-length n-alkanes of medium chain-length as a carbon source, could not assimilate the shorter chain-length n-alkanes and aromatic hydrocarbons tested so far. The n-alkane degrading enzyme activity was found in the mycelial extract of the organism.

• Journal of Life Science
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• v.10 no.3
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• pp.300-306
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• 2000

Several bacterial strains utilizing crude oil as their sole carbon and energy source were isolated from polluted marine by crude oil. One of the strains, named KCL-2 showed strong degradation activity for crude oil. This strain was identified as a Klebsiella sp. based on the morphological, biochemical, and physiological characteristics. The optimum cultural conditions were as follows; $27^{\circ}C$~$37^{\circ}C$ for temperature and 7.0 for initial pH. Additionally, the optimal concentration of sodium chloride was 3.0%, confirming indicating that this strain was derived from sea water.The strain KCL-2 could use several kinds of n-alkane hydrocarbones from octadecane to octacosane as a sole carbon source. The emulsifying activity by KCL-2 was the highest after 3 days of cultivation under the condition of 3.0% sodium chloride, pH 7.0 and 32$^{\circ}C$. This strain had several criptic plasmids.

• Journal of Environmental Science International
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• v.8 no.4
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• pp.451-456
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• 1999

Microorganisms utilizing petroleum as substrate were screened from the seawater in Pusan coastal area. Among them, fifty strains utilized bunker-A oil as a sole carbon and energy source. Five of these fifty strains were selected to experiment this study. According to the taxonomic characteristics of its morphological, cultural and biochemical properties, the selected stains were named Pseudomonas sp. EL-12, Flavobacterium sp. EL-15, Acinetobacter sp. EL-18, Enterobacter sp. EL-27 and Micrococcus sp. EL-43, respectively. The optimal medium compositions and cultural conditions for assimilation of bunker-A oil by the selected strains were 1.5-2% bunker-A oil, 0.1% $NH_4NO_3$, 1-1.5% $MgSO_4$.$7H_2O$, 0.05-0.15% KCl, 0.1-0.15% $CaCl_2$.$2H_2O$, 2.5-3.5% NaCl, initial pH 8-9, temperature 3$0^{\circ}C$ and aeration, respectively. The utilization and degradation characteristics on the various hydrocarbons by the selected stains were showed that bunker oil, n-alkane and branched alkane compounds were highly activity than cyclic alkane and aromatic hydrocarbon compounds.

• Prospectives of Industrial Chemistry
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• v.24 no.2
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• pp.22-30
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• 2021

현재 인류는 플라스틱(plastic) 세상에 살고 있다. 의류, 식품, 주거 생활 곳곳에 플라스틱이 존재하며, 플라스틱이 없는 세상은 상상조차 할 수 없다. 하지만, 플라스틱 사용량 증가에 따른 폐플라스틱의 배출량의 증가는 심각한 환경문제들을 야기하여 생태계뿐만 아니라 인간에게도 위협이 되고 있다. 이를 해결하기 위한 방법으로 단순히 폐플라스틱의 처리에 그치지 않고, 이를 활용하여 새로운 고부가가치의 생성물을 제조하는 플라스틱 업사이클링(plastic upcycling) 시스템이 최근 주목을 받고 있으며, 현재 다양한 형태로 연구개발이 진행되고 있다. 그 중의 한가지로 본 기고문에서는 알칸 교차 복분해(cross alkane metathesis) 반응을 소개한다. 알칸 교차 복분해 반응은 수소화/탈수소화(hydrogenation/dehydrogenation) 반응과 올레핀 복분해(olefin metathesis) 반응으로 이루어져, 탈수소화 반응 후 생성된 이중결합 탄소를 갖는 두 개의 알켄 화합물이 자리바꿈을 통해 새로운 이중 결합을 형성하는 반응이다. 이 촉매반응 과정이 반복되면 저분자화된 새로운 알칸 화합물을 생성되는데, 이는 기존의 플라스틱 처리방식인 열분해 및 촉매 분해 공정보다 낮은 반응온도를 요구한다. 또한 이를 통해 상대적으로 높은 순도의 가솔린 및 디젤을 생성할 수 있기 때문에 폐플라스틱 처리 공정의 새로운 대안기술이 될 수 있다. 본 기고문에서 폐플라스틱 중 가장 큰 비중을 차지하는 폴리에틸렌을 처리하는 대안기술로써 알칸 교차 복분해 반응의 메커니즘과 및 촉매의 역할, 그리고 반응성에 영향을 주는 인자에 대해 기술한다.

• Journal of Life Science
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• v.9 no.2
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• pp.76-81
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• 1999

216 microorganisms which able to degrade wasted lubricant were isolated in the region of contaminated with wated lubricant such automobile repair shops, garages and gas stations in Taejon. Most activated strain among them is selected and used in this research. The microorganism in identified as Acinetobacter lwoffii 16C-1, which shows active growth and hydrocargon utilization withnormal alkane such as tetradecane, hexadecane and octadecane, and do not grow aromatic hydrocargons, cycloalkane, and branched alkane. In addition, A. lwoffii 16C-1 has resistance to heavy metals such as Ba, Li, Cr, and Mn more than 6.4mg/ml, and showed negligible tolerance against antibiotics. Effects of environmental conditions including concentration of wasted lubricnt, pH, NaCl concentration, nitrogen source and phosphate on microorganism growth and emulsification were studied. 2% of wasted lubricant, pH 7.0, 0-1% of NaCl, 0.2% of peptone, and 0.01% of K2HPO4 is turn out to be optimum condition. By the analysis of remaining oils, almost of hydrocarbons added to the media are removed by A. lwoffii 16C-1 at 30$^{\circ}C$ after 2 days of culture, which showed excellent oil degradation characteristics.

• Journal of Microbiology and Biotechnology
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• v.19 no.4
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• pp.339-345
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• 2009

We evaluated the activity and abundance of the crude-oil-degrading bacterium Nocardia sp. H17-1 during bioremediation of oil-contaminated soil, using real-time PCR. The total petroleum hydrocarbon(TPH) degradation rate constants(k) of the soils treated with and without H17-1 were $0.103\;d^{-1}$ and $0.028\;d^{-1}$ respectively. The degradation rate constant was 3.6 times higher in the soil with H17-1 than in the soil without H17-1. In order to detect and quantify the Nocardia sp. H17-1 in soil samples, we quantified the genes encoding 16S ribosomal RNA(16S rRNA), alkane monooxygenase(alkB4), and catechol 2,3-dioxygenase(23CAT) with real-time PCR using SYBR green. The amounts of H17-1 16S rRNA and alkB4 detected increased rapidly up to 1,000-folds for the first 10 days, and then continued to increase only slightly or leveled off. However, the abundance of the 23CAT gene detected in H17-1-treated soil, where H17-1 had neither the 23CAT gene for the degradation of aromatic hydrocarbons nor the catechol 2,3-dioxygenase activity, did not differ significantly from that of the untreated soil($\alpha$=0.05,p>0.22). These results indicated that H17-1 is a potential candidate for the bioaugmentation of alkane-contaminated soil. Overall, we evaluated the abundance and metabolic activity of the bioremediation strain H17-1 using real-time PCR, independent of cultivation.

• Microbiology and Biotechnology Letters
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• v.23 no.3
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• pp.255-262
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• 1995

Intact cells of Acinetobacter sp. T5-7 completely degraded trichloroethylene (TCE) following growth with phenol. This strain could grow on at least eleven aromatic compounds, e.g., benzaldehyde, benzene, benzoate, benzylalochol, catechol, caffeic acid, 2.4-D, p-hydroxybenzoate, phenol, protocatechuate and salicylate, and did grow on alkane, such as octane. But except phenol, other aromatic compounds did not induced TCE degradation. Phenol biotransformation products, catechol was identified in the culture media. However, catechol-induced cells did not degrade TCE. So we assumed that phenol hydroxylase was responsible for the degradation of TCE. The isolate T5-7 showed growth in MM2 medium containing sodium lactate and catechol rather than phenol, but did not display phenol hydroxyalse activity, suggesting induction of enzyme synthesis by phenol. Phenol hydroxylase activity was independent of added NADH and flavin adenine dinucleotide but was dependent on NADPH addition. Degradation of phenol produced catechols which are then cleaved by meta-fission. We identified catechol-2.3-dioxygenase by active staining of polyacrylamide gel.

• Journal of Environmental Health Sciences
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• v.28 no.5
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• pp.35-41
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• 2002

This study was conducted to evaluate the effect of initial concentration on pilot-scale composting of diesel-con-laminated soil. Sandy soi] was used in this study. Target contaminant, diesel oil, was spiked. at about 10,000, 25,000, and 50,000 mg TPH/kg of dry roil. Mit ratio of soil to sludge was 1:0.5 as wet weight basis. Removal efficiencies for initial concentrations of 12,966,23,894 and 51,042 mg TPH/kg were 90, 93 and 54％, respectively, during 33 days of composting. Normal alkanes in TPH ranged from 15 to 22％ in initial soils. Volatilization of individual normal alkane in 1,999 mg n-alkanes/kgwas completed within 4 days, while n-alkane compounds of Cl1-Cl4 in 5,270 and 9,836 mg n-alkanes/kg were volatilized continuously during 33 days of composing operation. The first order degradation rate con-stants for 12,966, 23,894, and 51,042 mg TPH/kg were 0.058, 0.076, and 0.022/day, and those for 1,997 5,270, and 9,836 mg n-alkanes/kg were 0.093, 0.100, and 0.019/day, respectively. Considering TPH removal rate, $CO_2$porduction rate, and dehydrogenase activity, the concentration of 51,042 mg TPH/kg inhibited biodegradation of diesel-composting.