• Korean Journal of Microbiology
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• v.55 no.2
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• pp.143-148
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• 2019

The synthesis of captopril as an important chiral drug in commerce needs expensive resolution process of racemic mixture. Microorganisms, producing a thermostable esterase that catalyzes the stereo-selective hydrolysis of methyl DL-${\beta}$-acetylthioisobutyrate (DL-ester) to D-${\beta}$-acetylthioisobutyric acid (DAT) were screened from soils. Among the strains tested, strain No CJ-317 and strain No CJ-187 with highest activity were selected as the best DAT producer. The newly isolated microorganisms were identified respectively, as Klebsiella pneumoniae and Pseudomonas putida. The cell activity of esterase from K. pneumoniae CJ-317 and P. putida CJ-187 were showed an optimal reaction activity at $75^{\circ}C$ and $60^{\circ}C$, respectively. Also the cell activity of K. pneumoniae CJ-317 was stable up to $80^{\circ}C$ for 1 h, while that of P. putida CJ-187 was not over $60^{\circ}C$. By varying the concentration of DAT in the reaction mixture, the cell activity of P. putida CJ-187 showed about 55% and 80% of product inhibition in the presence of 2.5% (w/v) and 5.0% of DAT respectively. K. pneumoniae CJ-317 had less product inhibition than P. putida CJ-187 by about 35% and 44% at the same concentrations respectively. The esterase of newly isolated K. pneumoniae CJ-317 could be useful for the stereo-selective hydrolysis of DL-ester to DAT.

• Korean Journal of Microbiology
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• v.25 no.2
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• pp.87-93
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• 1987

The properties of the plasmid pKU41 isolated from Pseudomonas putkda KU190 have been investigated, pKU41 was defined as an R plasmid having a transmissible ampicillin and tetracycline resistance determinant, and could be classified as a plasmid belonging to IncP-1 group according to incompatibility grouping.

• Korean Journal of Microbiology
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• v.27 no.4
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• pp.334-341
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• 1989

Toluate degradative plasmid from Pseudomonas cepacia SUB37 was determined to be molecular weight as $79.3\times 10^6$

• Microbiology and Biotechnology Letters
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• v.17 no.4
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• pp.321-326
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• 1989

Eighty two bacterial strains have been isolated from five different soil and sewage samples by selective enrichment culture on m-toluate minimal medium. Two of these were identified as Pseudomonas capacia, one as P. putida, one as Yersinia intermedia, and one as Flavobaeterium odoratum. P. cepacia SUB37 appeared to carry plasmid superficially similar to TOL plasmid previously described in p. putida mt-2 and other two plasmids from Flavobacterium odorutum and Y. intermedia larger than that of p. putida mt-2. p. cepacia SUB37 was sensitive to streptomycin but resistant to rifampicin. P. cepacia SUB37 carrying plasmid metabolizes the hydrocarbons to benzoate and toluates via the corresponding alcohols and aldehydes. By the curing experiment, it appears that P. cepacia SUB37 carries TOL plasmid encoding for the enzymes responsible for the catabolism of toluene and xylene via benzoate and the toluates and then by meta pathway in the process of degradation of aromatic hydrocarbons. p. cepacia SUB37 degraded m-toluate rapidly to be very low level when it was fully grown.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.341-342
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• 2001

High cell density cultivation of Pseudomonas putida is often necessary for the VOC removal bioreactor. Supplying the feeding solution of C and N sources could accelerate the growth of cells. We changed the component of feeding solution and feeding time. showing that P. putida could be grown to a high density.

• Korean Journal of Microbiology
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• v.24 no.1
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• pp.51-56
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• 1986

Eight strains of the bacteria capable of growing on salicylate as the sole carbon source were isolated form soil and river water. Three of these isolates were identified as Acinetobacter calcoaceticus (AcBl), Pseuomonas putida biotype B (PpB2), and P. putida biotype A (PpB3). Effects of temperature, pH and C source concentration on biodegradation of salicylate by PpB3 were wxamined. The optimum conditions were as follows; $30^{\circ}C$ for temperature, 7.0 for pH, and 10mM for C source concentration. Ultraviolet scanning spectrum of the salicylate was measured. The spectrum has two peaks at 225nm and 292nm. The spectra of the culture filtrates indicate that ring degradation of salicylate is accomplished.

• KSBB Journal
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• v.16 no.3
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• pp.286-289
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• 2001

A beterotrophic Pseudomonas putida B2 was used to treat of hydrogen sulfide containing gas. The experimental approach involved operating two indentical bench-scale biofilters with media consisting of a mixture of peatmoss, perlite and granular activated carbon(GAC). One column was seeded with Pseudomonas putida B2 and the other was left unseeded. The biofilter was operated for 16 days under EBRT for 20-40 sec, at a temperature of 25-30$^{\circ}C$ and a hydrogen sulfide concentration of 40-190 ppm. The biofilter inocculated with P.putida B2 exhibited high hydrogen sulfide removal efficiency, average of 95%, at a gydrogen sulfide concentration of 40-190 ppm (flow rate 3.6 L/min). However, at a shock loading of 190 ppm the biofiter showed a removal efficiency of 78.9% and the control only showed a removal efficiency of 31.6%. The critical load of this biofilter was 14.83 g/㎥hr, and the critical load of the control column was 4.93 g/㎥hr. These results suggest that P. putida B2 has the potential to be used as a $H_2S$ removal agent in a biofilter.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.3
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• pp.278-286
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• 1995

Phosphate-solubilizing microorganisms were isolated from agricultural area in Korea, and the solubilizing potential of microorganisms was evaluated in vitro. Of the several microorganisms Pseudomonas putida, Penicillium sp., and Aspergillus niger showed solubilization in all phosphatic compounds such as hydroxyapatite, tricalcium phosphate, aluminium phosphate and rock phosphate tested. Inorganic P solubilization was directly related to the pH drop by each microorganisms. Aspergillus niger was found to be more active in solubilizing phosphate than Pseudomonas putida and Penicillium sp.. The maximum concentration of phosphorus released from each of aluminium phosphate, hydroxyapatite and tri-calcium phosphate by Aspergillus niger in liquid culture was 776ppm, 665ppm and 593ppm, respectively when $KNO_3$ was added as nitrogen source. For rock phosphate, it was 411ppm with ammonium sulfate as nitrogen source.

• Korean Journal of Microbiology
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• v.29 no.4
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• pp.226-229
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• 1991

In our laboratory a R plasmid pKU10 was isolated from Pseudomonas and its characteristics were investigated. In this study, as a basic work to improve its utility as a cloning vehicle, restriction patterns of pKU10 were analyzed for other various restriction enzymes in addition to restriction evdonucleases previously examined. As a result, pKU10 DNA has two cleavage sites for ClaI and HpaI, and three sites for AvaI. The restriction map of pKU10 was supplemented with AvaI, ClaI, and HpaI. From the result of this experiment, the usefulness of PKU10 as a cloning vector in Pseudomonas will be enhanced by constructions of mini-plasmid or hybrid plasmids.

• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.678-682
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• 2005

The promoter region of a carbon starvation gene isolated from Pseudomonas putida was cloned and analyzed for its potential use for in situ bioremediation and bioprocessing. We constructed a recombinant plasmid pMKD101 by cloning the 0.65 kb promoter region of the gene into the promoter proving vector, pMK301, which contains the lacZ for ${\beta}$-galactosidase activity as a reporter gene. pMKD101 was transformed into the wild-type P. putida MK1, resulting in P. putida RPD101, and analyzed for ${\beta}$-galactosidase activity under different culture conditions. When RPD101 was grown on the minimal medium plus $0.1\%$ glucose as a sole carbon source in batch cultures, ${\beta}$-galactosidase activity was found to be 3.2-fold higher during the stationary phase than during the exponential phase. In chemostat cultures, ${\beta}$-galactosidase activity was found to be 3.1-fold higher at the minimal growth rate (dilution rate=$0.05\;h^{-1}$) than at the maximal growth rate (dilution rate=$0.173;h^{-1}$). The results suggest that a carbon starvation promoter can be utilized to maximize the expression of a desired gene under nutrient limitation.