• Korean Journal of Microbiology
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• v.33 no.3
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• pp.193-198
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• 1997

Microorganisms capable of producing biosurfactant were isolated from oil-contaminated soils and seawater. Among them, the selected strain SW1 was identified as Pseudomonas sp. by taxonomical characteristic tests, and so tentatively named Pseudomonas sp. SWI. The optimal temperature and initial pH for biosurfactant production were TEX>30^{\circ}C.$ and 7.0, respectively. The optimal medium composilion for the production of biosurfactant by Pseudomonas sp. SW1 were hexadecane of 2.0%, yeast extract of 0.04%, $K_{2}HPO_4$ of 0.02%, $KH_2PO_4$ of 0.03% and $MgSO_4$ center dot $7H_2O$ of 0.04%, respectively. Under the above conditions, minimum wrface tension was 32 mN/m after incubation of 2 days. The biosurfactant was produced during initial stationary phase in the optimal medium. Pseudotnonas sp. SWl utilized various hydrocarbons such as Bunker oils, n-alkanes and branched alkanes as a sole carbon source.

• Microbiology and Biotechnology Letters
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• v.27 no.1
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• pp.41-45
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• 1999

A tentative composition and some properties of biosurfactants, type I and type II, from Pseudomonas sp. SW1 are described. Biosurfactant type I and II are soluble in water, dichloromethane, chloroform, and a mixture of chloroform and methanol, respectively. The UV absorption spectrum of biosurfactants showed three characteristic peaks in the range of 212, 250 and 365nm, respectively. As a result of IR spectroscopy, GC/MS analysis and biochemical analysis, biosurfactant type I was a polymeric biosurfactant containing carbohydrate, lipid and protein. The carbohydrate was characterized as rhamnose. The lipid part consists of $C_{14}-C_{23}$ fatty acid when analyzed by GC/MS. The biosurfactant type II was a rhamnolipid consisting of carbohydrate and lipid.

• Journal of Microbiology and Biotechnology
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• v.9 no.1
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• pp.56-61
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• 1999

Pseudomonas sp. SW1 grew and produced biosurfactants on 3% hexadecane as the energy and carbon source. As a result of biosurfactant synthesis, the surface tension of the medium was reduced from 72 dyne/cm to 30 dyne/cm. The properties of biosurfactants that were purified from Pseudomonas sp. SW1 were investigated. The purification procedure included acid precipitation from culture supernatant, silica gel G60 column chromatography, and Sephadex G-150 gel filtration. The biosurfactants were separated into two different types, viz., types I and II. Biosurfactant type Isignificantly reduced the surface tension of water from 72 to 27 dyne/cm at concentration levels above 30 mg/l. The surface tension of water was reduced to a minimum of approximately 30 dyne/cm by biosurfactant type II at concentration levels over 80 mg/l. The biosurfactants were effective in a wide range of pHs, at NaCl concentrations of up to 4%, at $CaCl_2$ concentration up to 100 mM, and at temperatures up to $200^{\circ}C$ for 8 h.

• Journal of Life Science
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• v.18 no.1
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• pp.84-90
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• 2008

Bacterial colonies which were able to oxidize the manganese were isolated from six soil samples in Byungchon area. Among them, one bacterial strain was selected for this study based on its high manganese oxidation activity. This selected bacterial strain was identified as Pseudomonas sp. MN5 through physiological-biochemical test and analysis of its 16s rRNA sequence. This selected bacterial strain was able to utilize fructose and maltose, but they doesn't utilizing various carbohydrates as a sole carbon source. Pseudomonas sp. MN5 showed a very sensitive to antibiotics such as kanamycin, chloramphenicol, streptomycin and tetracycline, but a high resistance up to mg/ml unit to heavy metals such as lithium, manganese and barium. Optimal manganese oxidation condition of Pseudomonas sp. MN5 was pH 7.5 and manganese oxidation activity was inhibited by proteinase K and boiling treatment. The manganese oxidizing protein produced by Pseudomonas sp. MN5 was purified by ammonium sulfate precipitation, HiTrap Q FF anion exchange chromatography and G3000sw $_{XL}$ gel filtration chromatography. By sodium dodecyl sulfate polyacrylamide gel electrophoresis, three manganese oxidizing protein with estimated molecular weights of 15 kDa, 46.7 kDa and 63.5 kDa were detected. Also, it was estimated that manganese oxidizing protein produced by Pseudomonas sp. MN5 were a kind of porin proteins through internal sequence and N-terminal sequence analysis.

• KSBB Journal
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• v.11 no.1
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• pp.37-45
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• 1996

Marine bacterial strain, highly effective agar degrading, was isolated from south sea of Korea and was identified as Pseudomonas sp. This strain was named Halophilic Pseudomonas sp. W7 and accumulated an extracellular agarase which showed a high level of enzyme activity in the presence of agar and agarose. This extracellular agarase was purified by anion-exchange chromatography and gel filtration. Purified agarase showed a single protein band upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis and its molecular weight was estimated to be about 89KDa. The agarase gene was cloned into Escherichia coli JM83 using the plasmid vector pUC19. DNA fragments(3.7, 3.0Kb) of Hind III-digested chromosomal DNA of Pseudomonas sp. W7 was inserted into the Hind III site of pUC19. Selected transformants, E. coli JM83/pSWl 000000and E. coli JM83/pSW3, produced agarase and this agarase was accumulated In the cytoplasmic space.

• Journal of Microbiology
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• v.41 no.2
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• pp.95-101
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• 2003

The lipase gene (lipA) and its activator gene (lipB) of Pseudomonas sp. SW-3 were cloned and sequenced. The lipB was found to be present immediately downstream of lipA. The deduced amino acid sequences of lipA and lipB showed a high level of homology to those of other lipases belonging to the family I.1 of bacterial lipases. When lipA was expressed in Escherichia coli using T7 promoter, an active lipase was produced in cells carrying both lipA and lipB, but not in cells harboring only lipA. Recombinant lipase (rPSL) overproduced in an insoluble form was solubilized in the presence of 8 M urea, purified in a urea-denatured form and refolded by removing urea in the presence of the Ca$\^$2+/ ion. rPLS had maximum activity at pH 8.0 and 50$^{\circ}C$, was stable at pHs from 7.0 to 9.0 and below 50$^{\circ}C$, and showed the highest activity toward the p-nitrophenyl ester of palmitate (Cl6).