• KSBB Journal
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• v.15 no.4
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• pp.342-345
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• 2000

A novel pre-purification method was developed for producing peroxidase to guarantee high purity and yield from plant cell cultures in large-scale process. This method was a simple and efficient procedure for the isolation and pre-purification of peroxidase from the biomass consisting of active clay treatment followed by cationic exchange chromatography. The use of active clay in the pre-purification process allows for rapid and efficient separation of peroxidase from interfering compounds and dramatically increases yield and purity of crude peroxidase for purification steps compared to alternative processes. This pre-purification process serves to minimize the buffer usage size and complexity of the HPLC operations for peroxidase purification. This process is readily scalable to a pilot plant and eventually to a production environment where mass production of material are expected to be produced.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.1
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• pp.12-16
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• 2004

Partitioning of human granulocyte-macrophage colony stimulating factor (hGM-CSF) was achieved in the aqueous two-phase systems (ATPSs) using a crude extract of transgenic tobacco cell suspension culture. This study examined the effects of polyethylene glycol (PEG) molecular weight and concentration and the effects of sodium phosphate concentration in different PEG/sodium phosphate systems on the partition coefficient, K. The best ATPS system was 5% PEG 8,000/1.6 M sodium phosphate after 2 h of incubation at room temperature. In this system, hGM-CSF was partitioned in the PEG-rich phase with a yield of 57.99% and K$\_$hGM-CSF/ of 8.12. In another system, 3% PEG 10,000/1.6 M sodium phosphate, hGM-CSF was also partitioned primarily in the top phase with a yield of 45.66% and K$\_$hGM-CSF/ of 7.64 after 2 h of incubation at room temperature.

• Elastomers and Composites
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• v.50 no.1
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• pp.30-34
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• 2015

Thermo-mechanical treatment process of a compressed open-cell rigid polyurethane foam (OC-RPUF), which was fabricated for the vacuum insulation panel (VIP), was studied to obtain an optimum condition for the dimensional stability by the relaxation of compressive stress. Thermo-mechanical deformation of the sample OC-RPUF was shown to occur from about $120^{\circ}C$. Yield stress of 0.36 MPa was shown at about 10% yield strain. And, densification of the foam started to occur from 75% compressive strain and could be continued up to max. 90%. Compression set of the sample restored after initial compression to 90% at room temperature was ca. 82%. Though the expansion occurred to about twice of the originally compressed thickness in case of temperature rise to $130^{\circ}C$, it could be overcome and the dimensional stability could be maintained if the constant load of 0.3 MPa was applied. As the result, a thermo-mechanical treatment process, i.e, annealing process at temperature of $130{\sim}140^{\circ}C$ for about 20 min as is the maximum compressed state at room temperature, should be required for dimensional stability as an optimum condition for the use of VIP core material.

• Journal of Ginseng Research
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• v.34 no.4
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• pp.321-326
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• 2010

Enzymatic treatment conditions for red ginseng residue (RGR) were investigated to apply RGR as a microbial medium. Polysaccharide hydrolyase and protease were screened to obtain high solid and carbohydrate yields, and a good degree of carbohydrate hydrolysis. The optimal dosage and reaction time for Viscozyme, the chosen polysaccharide hydrolyase, were found to be 1.0% (w/w) and 3 h, respectively. Of the tested proteases, Flavourzyme, whose optimal dosage was 0.5% (w/w), was selected. Co-treatment with the optimal dosages of Flavourzyme and Viscozyme increased solid yield, carbohydrate yield, and degree of carbohydrate hydrolysis by 76%, 65%, and 1,865%, respectively, over levels in non-treated RGR. The culture characteristics of Leuconostoc mesenteroides strain KACC 91459P grown in enzymatically hydrolyzed red ginseng residue (ERGR) and RGR suspensions were compared. After cultivation for 6 h, the viable cell counts of both cell suspensions rapidly increased to $1.3{\times}10^9$ colony-forming units (CFU)/g. Moreover, while the viable cell population drastically decreased to $2.4{\times}10^6\;CFU/g$ for cells grown in RGR medium, it was maintained in cells fermented in ERGR medium for 24 h.

• Corrosion Science and Technology
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• v.2 no.3
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• pp.109-116
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• 2003

It is well known that SSCC (sulfide stress corrosion cracking) is caused by drastic ingression of hydrogen during the service and accumulation of hydrogen near the potential crack initiation site in the material. It is important to characterize the hydrogen trapping behavior to evaluate the service performance of the high strength pipeline steels. In this study. the relationship between the hydrogen trapping behavior and SSCC susceptibility is evaluated in terms of alloy composition, microstructure and carbide behavior. The hydrogen trapping behavior was measured by electrochemical hydrogen permeation test cell (Devanathan cell). The SSCC susceptibility is evaluated by constant extension rate test and constant strain lest method. The hydrogen trapping behavior is affected greatly by microstructure and nature of carbide particles. The fine TiC, and NbC in the matrix of ferritic structure acts as strong irreversible trap sites whereas the bainitic structure acts as reversible trap site. The SSCC susceptibility is closely related to not only the hydrogen trapping behavior but also the loading condition. As the activity of reversible trap site increases, SSCC susceptibility decreases under static loading condition below yield strength, whereas SSCC susceptibility increases under dynamic loading condition or above yield strength. As the activity of irreversible trap site increases. SSCC susceptibility increases regardless of loading condition. It is cased by the mixed effect of dislocation on hydrogen diffusion and trapping behavior.

• Journal of Microbiology and Biotechnology
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• v.25 no.4
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• pp.452-458
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• 2015

The biocatalytic efficiency of recombinant Corynebacterium glutamicum ATCC 13032 expressing the secondary alcohol dehydrogenase of Micrococcus luteus NCTC2665 was studied. Recombinant C. glutamicum converts ricinoleic acid to a product, identified by gas chromatography/mass spectrometry as 12-ketooleic acid (12-oxo-cis-9-octadecenoic acid). The effects of pH, reaction temperature, and non-ionic detergent on recombinant C. glutamiucm whole cell bioconversion were examined. The determined optimal conditions for production of 12-ketooleic acid are pH 8.0, 35℃, and 0.05 g/l Tween80. Under these conditions, recombinant C. glutamicum produces 3.3 mM 12-ketooleic acid, with a 72% (mol/mol) maximum conversion yield, and 1.1 g/l/h volumetric productivity in 2 h; and 3.9 mM 12-ketooleic acid, with a 74% (mol/mol) maximum conversion yield, and 0.69 g/l/h maximum volumetric productivity in 4 h of fermentation. This study constitutes the first report of significant production of 12-ketooleic acid using a recombinant Corynebacterium glutamicum-based biocatalyst.

• YAKHAK HOEJI
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• v.33 no.6
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• pp.365-371
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• 1989

Microbiological conversion of sterols to 17-ketosteroids has been recognized as a source for commercial preparation of steroidal drugs. In order to develop bacterial strains and process with Brevibacterium lipolyticum IAM 1398 capable of converting cholesterol to 1,4-Androstadiene-3,17-dione (ADD) at about 27% yield, we studied on strain improvement, fermentation condition and whole cell immobilization. By using UV and/or NTG as mutagens, a mutant to convert cholesterol to ADD with higher yield than 60% was selected. Better production of ADD was manifested in the case of maltose used as a supplemental carbon source, and yeast extract or soytone as a nitrogen source. Addition of tween 80 (0.05%) as a surfactant beneficial for increasing the productivity. The optimal initial pH of the medium was 6.5 and optimal culture temperature was $30^{\circ}C$. Whole cell immobilization by using carrageenan, agar, alginate and acrylamide was carried out and the activity of conversion was tested. In the case of carrageenan and agar, immobilized cells were active for at least two cycles of fermentation.

• Journal of Korea Foresty Energy
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• v.21 no.1
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• pp.49-55
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• 2002

A comparative study on the structure of wood and charcoals was examined by scanning electron microscopy. Four species as Quercus variabilis $B_LUME$, Quercus mongozica $F_ISCH$ , Fraxinus rhynchcphylla $H_ANCE$ and Prunus sargentii $R_EHDER$ were used for this experiment. Cell dimensions of charcoals showed more higher shrinkage than those of wood. Shape of vessels was slightly changed due to become smaller in tangential diameter. Therefore, it was considered that the decrease of charcoal yield was caused by decrease of cell dimensions as well as loss of wood components.

• Journal of Korea Society of Waste Management
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• v.34 no.7
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• pp.685-696
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• 2017

This study focuses on computational particle fluid dynamics (CPFD) modeling for the fast pyrolysis of biomass in a conical spouted bed reactor. The CPFD simulation was conducted to understand the hydrodynamics, heat transfer, and biomass fast pyrolysis reaction of the conical spouted bed reactor and the multiphase-particle in cell (MP-PIC) model was used to investigate the fast pyrolysis of biomass in a conical spouted bed reactor. A two-stage semi-global kinetics model was applied to model the fast pyrolysis reaction of biomass and the commercial code (Barracuda) was used in simulations. The temperature of solid particles in a conical spouted bed reactor showed a uniform temperature distribution along the reactor height. The yield of fast pyrolysis products from the simulation was compared with the experimental data; the yield of fast pyrolysis products was 74.1wt.% tar, 17.4wt.% gas, and 8.5wt.% char. The comparison of experimental measurements and model predictions shows the model's accuracy. The CPFD simulation results had great potential to aid the future design and optimization of the fast pyrolysis process for biomass.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.2
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• pp.142-146
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• 2003

Three insect cell lines, Sf9, Sf21 and Tn5Bl-4, and four different kinds of serum free media (SFM), Sf 900 II, EX-CELL 420, EX-CELL 405 and Express Five, were used to compare the nutrient consumption, byproduct formation, production of recombinant protein and protease activity in suspension cultures. The Sf 900 II SFM was a ppropriate for the cell growth and protein production of the Sf9 and Sf21 cell lines. When the Tn5Bl-4 cell line was grown in the Express Five SFM, the specific growth rate was 1.6 fold higher than those of either the Sf9 or Sf21 cell lines. The glucose and glutamine consumption rates per cells, were 4 and 2.3 times higher than those of the Sf9 cell line, respectively. The overall yield coefficients of the lactate and ammoniumion were 2.8 and 1.5 times higher compared to those of the Sf9 cell line. respectively. The maximum specific ${\beta}$-galactosidase production rate was 4.5 fold that of the Sf9 cell line, a 3 times higher protease activity per cell.