• Korean Journal of Microbiology
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• v.38 no.4
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• pp.254-259
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• 2002

A psychrotrophic bacterium was isolated from Antarctic marine sediment and identified as Shewanella sp. species based on the biochemical properties and 16S rRNA sequence, and designated as Shewanella sp. L93. Extracellular protease produced by this strain was purified through ammonium sulfate precipitation, High-Q column chromatography, first gel permeation chromatography, BioScale Q2 ion exchange chromatography and second gel permeation chromatography, and basic properties of this enzyme were investigated.

• Microbiology and Biotechnology Letters
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• v.26 no.5
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• pp.413-419
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• 1998

Aryl acylamidase [EC 3.5.1.13] present in an acetaminophen-assimilating Pseudomonas sp. has been purified to a homogeneity using series of ammonium sulfate fractionation, DEAE-Sephacel anion exchange, Phenyl-Sepharose CL-4B hydrophobic, and Sephadex G-100 gel-permeation chromatography. The molecular weight, which was estimated by gel-permeation filtration and sodium dodecyl sulfate polyacylamide gel electrophoresis, was about 57 kDa and 56 kDa, respectively, indicating that this enzyme is a monomeric protein. The optimum pH was 10.5 and the optimum temperature was 40$^{\circ}C$. After incubation of the enzyme at 50$^{\circ}C$ for 30 min, residual activity of the enzyme was 34% compared to its original activity. The Km values for acetaminophen and 4'-nitroactanilide were 0.10 mM and 0.11 mM, respectively.

• Korean Journal of Microbiology
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• v.37 no.3
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• pp.182-188
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• 2001

The glucoamylase was purified from the induced culture filtrate of hybrid between Saccharomycopsis sp. and Saccharomycopsis sp. made by nuclear transfer and characterized for some enzyme properties. The enzymewas purified 76-fold in an overall yield of 16% from the culture medium by ammonium sulfate fractionation,Sephadex G-150 gel permeation chromatography and DEAE-Sephadex A-50 ion exchage chromatography.The molecular weight of the purified glucoamylase was estimated to be 57.5 KDa on SDS-polyacrylamidegel electrophoresis and Sephadex G-150 gel permeation chromatography. The purified enzyme was active atpH-5.0 and $40^{\circ}C$. The Km value for soluble starch was 2.6 mg/ml. The enzymatic activity was stimulated inthe presence of TEX>$Ca^{2+}$, EDTA, $Co^{2+}$, $Mg^{2+}$, and $Mn^{2+}$

• Microbiology and Biotechnology Letters
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• v.13 no.2
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• pp.157-162
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• 1985

The cell cultures and crude extracts of Bacillus sphaericus 1593 K-5 and its mutant Spo-Dl216 were respectively bioassayed against Culex pipiens var. pollens mosquito larvae. The B. sphaeriucs 1593 K-5 showed toxic activity against the larvae. LC$_{50}$ values (cells/$m\ell$) was 2.6$\times$10$^2$. Also the LC$_{50}$ ($\mu\textrm{g}$ Protein/$m\ell$) of the crude extract was 10.26. However, B. sphaericus Spo-Dl216 didn't show toxic activity against the larvae. The soluble cytoplasmic toxin in broken B. sphaeriucs 1593k-5 cells was partially purified by gel permeation chromatography and ion exchange chromatography. Among the fractions of the gel permeation chromatography only a single fraction was found to be toxic. LC$_{50}$ values ($\mu\textrm{g}$ protein/$m\ell$) of the active fraction was 0.182. The active fraction of the gel permeation was subjected to ion exchange chromatography. Only a single fraction showed toxic activity and its LC$_{50}$ values ($\mu\textrm{g}$ protein/$m\ell$) was 0.02..02.

• Microbiology and Biotechnology Letters
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• v.17 no.1
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• pp.19-23
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• 1989

A sequential system composed of hydroxylapatite chromatography and gel permeation chromatography was developed to purify the IgM type monoclonal antibody against the colon cancer cell SC-1 from the ascitic fluid of mice injected with the murine hybridoma CH07E02. In the hydroxylapatite chromatographic step the band dilution could be reduced by controlling the gradient and flow rate of the eluent, the sodium phospate buffer, the optimum values for these variables being 5.82$\times$10$^{-3}$M/cm and 0.2$m\ell/\textrm{cm}^2$/min, respectively. A degree of purity better than 99.99% as judged from silverstaining of the SDS-PAGE bands, was obtained by adding the gel permeation chromatographic step in tandem.

• Elastomers and Composites
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• v.4 no.1
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• pp.56-61
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• 1969

• Korean Journal of Microbiology
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• v.23 no.4
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• pp.241-247
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• 1985

The objectives of this study were to isolate and identify ninhydrin positive substande(s) produced in the culture broth of Pseudomonas fluorescens. It was found that the NPS could stimulate bioconversion of furfural into furoic acid. In order to isolate the NPS from the culture broth, cell free filtrate was subjected to ion-exchange chromatography, gel-permeation and finally to cellulose column chromatography. The purified NPS was white amorphous power and very soluble in water, slightly soluble in methanol and very insoluble in organic solvents. UV, and IR absorption spectra. $^H$ and $^{13}C-NMR$ were measured in order to identify the chemical structure of the NPS.

• Journal of the Korean Wood Science and Technology
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• v.45 no.4
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• pp.471-481
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• 2017

As the molecular weight (MW) of urea-formaldehyde (UF) resins had a great impact on their properties, this work was conducted to study effect of analytical parameters of gel permeation chromatography (GPC) on the MW measurement of UF resins. GPC parameters such as flow rate, column, detector temperature, and sample injection temperature were selected to compare number-average molecular weight (Mn), weight-average molecular weight (Mw), molecular weight distribution (MWD) and polydispersity index (PDI) of two UF resins with different viscosities. As expected, UF resin with higher viscosity resulted in greater Mn and Mw than those of low viscosity UF resin. When the flow rate increased, both Mn and Mw of UF resins decreased and MWD became narrower. By contrast, both Mn and Mw increased and MWD became wide when the column, detector, and sample injection temperature increased. The column, detector, and sample injection temperature of $50^{\circ}C$ at a flow rate of $0.5m{\ell}/min$ resulted in the highest MW and broadest MWD for the GPC analysis. These results suggest that the apparent molecular size or a hydrodynamic radius of UF resin molecules dissolved in the mobile phase affect to Mn, Mw and MWD.

• Journal of Microbiology and Biotechnology
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• v.8 no.1
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• pp.92-95
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• 1998

Overproduction of Escherichia coli thiol peroxidase in the periplasmic space was achieved by locating the appropriate gene on a downstream region of the strong T7 promoter. E. coli strain BL21 carrying the recombinant plasmid pSK-TPX was induced by IPTG, lysed, and analyzed by SDS-polyacrylamide gel electrophoresis. A large amount of the overexpressed thiol peroxidase was located in the periplasmic space. A homogeneous thiol peroxidase was obtained from E. coli osmotic shock fluid by simple one-step gel permeation chromatography.

• Analytical Science and Technology
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• v.8 no.4
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• pp.465-468
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• 1995

Matrix assisted laser desorption ionization in mass spectrometry is a fast and accurate method to determine the molecular weight of natural and synthetic polymers. Unknown peptides such as elastase inhibitor and $\small{D}$-hydantoinase were analyzed using sinapinic acid as matrix and their molecular weights were compared with the results from protein sequencer and gel filtration chomatography, respectively. Synthetic polymers such as polyethyleneglycol, polypropyleneglycol, polydimethylsiloxane, and polystyrene were analyzed using matrices such as 2,5-dihydroxybenzoic acid, 4-hdroxyazobenzenecarboxylic acid, and 2-nitrophenyl octyl ether. Average molecular weights of polystyrene were compared with molecular weights by gel permeation chromatography.