• Journal of Microbiology and Biotechnology
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• 제15권5호
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• pp.946-951
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• 2005

Biodegradation of the endocrine-disrupting chemical di-n-butyl phthalate (DBP) was investigated using a bacterium, Pseudomonas fluorescens B-1, isolated from mangrove sediment. The effects of temperature, pH, salinity, and oxygen availability on DBP degradation were studied. Degradation of DBP was monitored by solid-phase extraction using reversed-phase HPLC and UV detection. The major metabolites of DBP degradation were identified as mono-n-butyl phthalate and phthalic acid by gas chromatography-mass spectrometry (GC-MS) and a pathway of degradation was proposed. Degradation by P. fluorescens B-1 conformed to first-order kinetics. Degradation of DBP was also tested in seawater by inoculating P. fluorescens B-1, and complete degradation of an initial concentration of $100{\mu}g/l$ was achieved in 144 h. These results suggest that DBP is readily degraded by bacteria in natural environments.

• 한국식물병리학회지
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• 제14권1호
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• pp.13-18
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• 1998

The use of bioluminescence as a sensitive marker for the detection of Pseudomnas sp. in the rhizosphere was investigated. Transposon Tn4431 which contains a promoterless luciferase operon and tetracycline resistant gene was used. This transposon, present on a suicide vector (pUCD623) in E. coli HB101, was mated with spontaneous rifampicin mutant of Pseudomonas fluorescens B16, a plant growth promoting rhizobacteria (PGPR), and then rifampicin and tetracycline resistant survivors were isolated. Twenty tow mutants wer isolated from the conjugants between E. coli HB101 and P. fluorescens B16. One of these, B16::Tn4431 (L22) recombinant which glowed brightly in the dark was selected for analysis. The cucumber seeds inoculated with L22 were grown in moisten two layers of filter paper and nonsterile soil contained in half cut PVC pipe. The roots were removed from the filter paper and PVC pipe, then placed on the 1/2 LB media plates. The plates were incubated at room temperature for 16 hr. L22 could successfully be detected in the rhizoplane by using the ordinary negative camera film (ASA100-400) with 30 minutes exposure under dark condition. The root colonizing ability and the plant growth promoting effect of L22 were not reduced compared to the untreated bacteria and wild type. L22 was superior to will type.

• 한국환경농학회지
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• 제20권1호
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• pp.50-56
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• 2001

부패된 콩이나 콩나물에 존재하는 33종$(K-1{\sim}K-33)$의 각종 미생물로부터 콩나물 부패에 관여하는 세균(K-17)과 진균(K-28)을 각각 1종류씩 분리하였으며, 이들은 각각 Erwinia carotovora와 Fusarium sp.로 동정하였다. 콩나물 부패균에 길항하는 미생물은 각종 토양 균원시료로부터 분리한 350여종의 세균을 이용하여 콩나물 부패세균인 K-17 균주와 진균인 K-28 균주에 각각 길항력을 나타내는 J-232 세균을 최종 선발하였다. 길항균 J-232는 Pseudomonas fluorescens로 동정되었다. 콩나물 부패균 E. carotovora K-17과 Fusarium sp. K-28의 배양액으로 재배한 콩나물은 시루 아랫부분이 부패하였으나, 길항균 P. fluorescens J-232는 PDA 한천배지에서도 부패균들의 생육을 억제하였을 뿐만아니라 길항균 배양여액을 단독으로 콩나물재배에 처리할 경우에도 시루 내 콩나물은 부패되지 않았다. 콩나물 부패균 E. carotovora K-17과 Fusarium sp. K-28의 배양액에 길항균 P. fluorescens J-232의 배양액을 원액 또는 500배까지 희석하여 침지한 후 재배한 콩나물도 전혀 부패되지 않았으며 생육이 약간 촉진되는 경향이었다.

• 농업과학연구
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• 제40권1호
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• pp.27-34
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• 2013

본 연구는 원유의 내냉성 미생물의 계절별 분포에 관해 조사하기 위해서 수행하였다. 내냉성 미생물은 최적 생장온도가 $30^{\circ}C$ 근처이지만, $7^{\circ}C$ 이하에서도 생존가능한 균으로 Pseudomonas, Achromobacter, Aeromonas 속 등이 있다. 원유로부터 분리한 총 내냉성 미생물 균수는 다른 계절에 비해 겨울철 원유에서 $3.0{\times}10^4$ CFU/mL로 가장 높은 수준으로 검출되었고, 다른 지역에 비해 B 지역에서 $2.4{\times}10^5$ CFU/mL로 유의적으로 높은 균수가 측정되었다(p<0.05). 분리한 총 706개의 균을 동정한 결과는 Gamma-proteobacteria 강이 전체의 81.02%로 가장 우세하였고, 그 중 Pseudomonas 속이 32.34%로 가장 높은 검출 빈도수를 나타내었으며, 특히 Pseudomonas fluorescens가 39.46%로 가장 우세하였다. 동정된 내냉성 미생물의 지역별 분포는 A 지역은 12개의 Acinetobacter johnsonii, B 지역은 21개의 Pseudomonas fluorescens, C 지역은 13개의 Enterobacter amnigenus, D 지역은 19개의 Psychrobacter maritimus, E 지역은 19개의 Acinetobacter johnsonii, F 지역은 8개의 Acinetobacter haemolyticus, G 지역은 20개의 Pseudomonas fluorescens, H 지역은 9개의 Acinetobacter johnsonii, I 지역은 17개의 Pseudomonas mucidolens가 높은 검출 빈도수를 나타내었다.

• 한국균학회지
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• 제20권2호
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• pp.109-117
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• 1992

운동성을 띠는 5가지 부생균과 1종류의 식물병원세균으로 Agrobacterium radiobacter, Bacillus subtilis, B. polymyxa, Pseudomonas aeruginosa, P. fluorescens 및 Xanthomonas malvacearum을 공시하여 이들 세균이 Cochliobolus sativus 분생포자, Fusarium oxysporum f. sp. ciceri의 후막포자, Macrophomina phaseolina의 균핵 및 Phytophthora drechsleri f. sp. cajani 난포자의 분비물에 미치는 화학주성을 서로 다른 무생물적 조건하에서 실험하였다. 균의 분비물의 농도와 세균세포의 끌리는 유인사이에는 정상관$(r=0.76{\sim}0.89)$이 있었다. 유사한 결과로서 화학주성반응과 배양간격에서도 통계적인 정상관이 있다$(r=0.82{\sim}0.95)$. 세균의 화학주성반응은 온도와 pH에 크게 영향을 받는다. 최적 화학주성을 나타내는 온도로서 A. radiobacter는 $25^{\circ}C$, B. polymyxa, P. aerugionosa, p. fluorescens and X. madracearum은 $30^{\circ}C$이었고, B. subtilis는 $35^{\circ}C$가 최적이었다. 최대 화학주성을 나타내는 분비물의 주성은 pH7이고 pH3과 11에서는 buffer와 같았다. 시험용 모세관에 유인물질이나 buffer 중 어느 종류가 채워져도 유인물질이 있는 시험관에 연결되면 세균은 주성이 나타난다는 것이 증명되었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.445-448
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• 2002

The Pseudomonas fluorescens KCTC 1767, a selected and identified as potential candidate for stereo-specific resolution of rac-ketoprofen ethyl ester, was systematically investigated in order to induce the high level expression and detailed characterization of the expressing enzyme esterase. We cloned the esterase gene from chromosomal DNA of Pseudomonas fluorescens KCTC 1767 by PCR with two synthetic primers that desinged for simple purification. The recombinant esterase from Pseudomonas fluorescens KCTC 1767 exibited a high conversion rate and enantioselectivity to the (S)-ketoprofen ethyl ester as expected. The enzyme was easily purified to homogeniety by using a metal chelating affinity chromatography as a protein with poly histidine taq, and thus obtained 0.6 mg of protein from a 100 mL culture broth in a single step. The purified enzyme was steadily stable at the pH range from 7.0 to 10. The activity was also retained to be about 70% after the preincubation at $40^{\circ}C$ but over $50^{\circ}C$ lost the activity completely. The molecular mass of the esterase was estimated to be about 43 kDa on SDS-PAGE, and an identical result was also shown in gel filteration chromatography. The specific activity was calculated 27 mM/mg-protein/min by using the rac-ketoprofen ethly ester as a substrate.

• 한국식품영양학회지
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• 제9권3호
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• pp.275-280
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• 1996

For the selection of powerful antagonistic bacterium for biological control of Ewinia sp. causing vegetable soft rot, two excellent strains (54, 565) were selected from 1, 196 strains of bacteria which were isolated from rhizospere in vegetable root rot suppressive soil. Selected 2 strains were identified to be a species to Pseudomonas fluorescens S4 and pseudomonas fluorescens S65 (PS65). The highest of inhibitory activity was produced in 523 synthetic broth medium at pH 7.0 and 25t during 3 ethyl-Al-folpet, and the antibiotics such as vancomycin, perucillin and lincomycin, only PS4 was resistant to erythromycin.

• Journal of Microbiology
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• 제39권4호
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• pp.338-342
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• 2001

Pseudomonas fluorescens SM11 is a naphthalene-degrading strain whose dissimilatory genes are cho-mosomally encoded. We have cloned the 2.9 kb Sal I fragment harboring genes for the naphthalene-degrading upper pathway. The nucleotide sequences were determined to be nahQ, napA, and partial regions of nahE genes. The nahQ encods a protein of 188 amino acid residues with a deduced molec-ular wight of 20.8kDa. The high homology with other proteins suggests that NAhQ may be an active and useful protein whtich gives as selective advantage to naphthalene degradatin. Transposase(TnpA)encodes a polypetide chain with a molecular mass of 41.8kDa consisting of 376 amino acid residues. The deduced anino acid sequence of tnpA revealed 96% idenitity with putative transposase of P. stutzeri OX1,. It was assumed that transposase plays an important role in the evloution of the catabloic-path way in the regulation of nah expression.

• 한국토양비료학회지
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• 제33권4호
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• pp.275-282
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• 2000

고추 시설 재배지 토양, 근권과 근면등으로부터 형광성 pseudomonads를 분리한 후 이들 중 35균주에 대해 계통 분석을 실시하였다. 계통 분석에 이용된 분류키는 165 rDNA의 일부 염기서열로, 종 수준에서 분류동정을 실시하였다. 고추재배지로부터 분리된 형광성 pseudomonads중 P. putida group으로 분류된 균주는 17균주 였으며, 이들은 주로 비근권 토양으로부터 분리되었다. 이들은 4개의 소그룹 (subgroup I, II, III, IV)으로 분류되었으며, 소그룹 I, IV에 속한 균주는 P putida의 표준균주가 속한 소그룹 II, III의 균주와는 분류학적으로 뚜렸히 구분되는 독특한 균주들이었다. P. fluorescens로 분류된 균주는 15균주였으며, 나머지 3균주는 P. fluorescens와 P. chloraphis의 중간 그룹으로 분류되었다. 근권으로부터 분리된 균주는 대부분 P. fluorescns로 분류되었으며, 이들의 유전적 유연관계는 매우 높게 나타났다. 본보의 결과에 비추어 볼 때, 고추의 근계는 P. fluorescens의 특정 균주에 의해 정착되는 것으로 생각되었다.

• 한국미생물·생명공학회지
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• 제48권2호
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• pp.223-229
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• 2020

The application of plant-growth-promoting rhizobacteria (PGPR) supports the growth of plants in contaminated soil while ureolytic bacteria can immobilise heavy metals by carbonate precipitation. Thus, dual treatment with such bacteria may be beneficial for plant growth and bioremediation in contaminated soil. This study aimed to determine whether the PGPR Pseudomonas fluorescens could work in synergy with ureolytic bacteria to assist with the remediation of cadmium (Cd)- and lead (Pb)-contaminated soils. Pot experiments were conducted to grow radish plants in Cd- and Pb-contaminated soils treated with PGPR P. fluorescens and the results were compared with dual inoculation of P. fluorescens combined with ureolytic Staphylococcus epidermidis HJ2. The removal rate of the metals from the soil was more than 83% for Cd and Pb by the combined treatment compared to 17% by PGPR alone. Further, the dual treatment reduced the metal accumulation in the roots by more than 80%. The translocation factors for Cd and Pb in plant tissues in both treatments remained the same, suggesting that PGPR combined with the carbonate precipitation process does not hamper the transfer of essential metal ions into plant tissues from the soil.