• Microbiology and Biotechnology Letters
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• v.16 no.4
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• pp.327-333
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• 1988

For optimal production of recombinant human interleukin-2 (IL-2) in E. coli the effect of fermentation conditions on cell growth, IL-2 production, and stability of recombinant cells were investigated. Among the complex nutrients tested in this work, yeast extract, peptone and corn steep liquor were found to be effective for recombinant cell growth. The recombinant cells were maintained stably under repression condition (3$0^{\circ}C$), but the stability of recombinant cells were drastically reduced upon induction of IL-2 expression (42$^{\circ}C$) even under the selection pressure. Addition of antibiotics to the culture medium resulted in the cell growth inhibition without significant improvement in recombinant stability. When the expression of IL-2 gene was induced at different growth phases, highest IL-2 production was achieved by the induction of IL-2 at the middle-exponential growth phase. It was found that the production of IL-2 significantly inhibited the cell growth and the ex-pression of other genes in the plasmid.

• Journal of Ginseng Research
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• v.40 no.4
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• pp.453-461
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• 2016

Background: This study aims to describe the characterization of Paenibacillus polymyxa GBR-1 (GBR-1) with respect to its positive and negative effects on plants. Methods: The morphological characteristics of GBR-1 were identified with microscopy, and subjected to Biolog analysis for identification. Bacterial population and media optimization were determined by a growth curve. The potential for GBR-1 as a growth promoting agent, to have antagonistic activity, and to have hydrolytic activity at different temperatures was assessed. The coinoculation of GBR-1 with other microorganisms and its pathogenicity on various stored plants, including ginseng, were assessed. Results: Colony morphology, endospore-bearing cells, and cell division of GBR-1 were identified by microscopy; identification was performed by utilizing the Biolog system, gas chromatography of fatty acid methyl esters (GC-FAME). GBR-1 showed the strongest antagonistic activity against fungal and bacterial pathogens. GBR-1 cell numbers were relatively higher when the cells were cultured in brain heart infusion (BHI) medium when compared with other media. Furthermore, the starch-hydrolytic activity was influenced by GBR-1 at higher temperature compared to low temperatures. GBR-1 was pathogenic to some of the storage plants. Coinoculation of GBR-1 with other pathogens causes differences in rotting on ginseng roots. A significant growth promotion was observed in tobacco seedlings treated with GBR-1 suspensions under in vitro conditions, suggesting that its volatile organic compounds (VOCs) might play a role in growth promotion. Conclusion: The results of this study indicate that GBR-1 has both positive and negative effects on ginseng root and other stored plants as a potential biocontrol agent and eliciting in vitro growth promotion.

• Microbiology and Biotechnology Letters
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• v.23 no.5
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• pp.593-598
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• 1995

The cultural conditions of Bullera singularis were optimized for the efficient production of galactooligosaccharide (GOS), Optimum temperature was 25$\circ$C, pH was 6.0, inoculum size was over 5% (v/v), initial lactose concentration was over 5% (w/v). The GOS production increased with microbial growth. Maximum amount of 72% (w/w) GOS was obtained from the optimized medium (5% lactose and 0.75% yeast extract) in 70 hours. Seven types of GOS (3 of dimer, 2 of trimer, 1 of tetramer, and 1 of pentamer) were identified by two-dimensional TLC. A new mechanism of GOS production is proposed based on the metabolism of carbon source.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.617-621
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• 2002

In order to optimize the carrot hairy root culture for SOD production, a fed-batch culture of hairy roots was performed in a bioreactor. Maximum SOD activity was obtained when the hairy roots were transferred to the MS medium containing 110 g/1 concentration of sucrose. By controlling the sucrose concentration (70 g/1 sucrose for growth and 110 g/1 sucrose far production, respectively) In a two-stage fed-batch culture, 29 g/1 of the hairy roots was obtained based on the final dry mass. The volumetrically determined SOD activity and productivity in the fed-batch culture were about 6 times higher than those from the flask culture containing sucrose at 30 g/1 concentration.

• Journal of Microbiology and Biotechnology
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• v.18 no.12
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• pp.1919-1926
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• 2008

Statistical experimental designs; involving (i) a fractional factorial design (FFD) and (ii) a central composite design (CCD) were applied to optimize the culture medium constituents for production of a unique antifreeze protein by the Antartic micro algae Chaetoceros neogracile. The results of the FFD suggested that NaCl, KCl, $MgCl_2$, and ${Na}_{2}{SiO}_{3}$ were significant variables that highly influenced the growth rate and biomass production. The optimum culture medium for the production of an antifreeze protein from C. neogracile was found to be Kalle's artificial seawater, pH of $7.0{\pm}0.5$, consisting of 28.566 g/l of NaCl, 3.887 g/l of $MgCl_2$, 1.787 g/l of $MgSO_4$, 1.308 g/l of $CaSO_4$, 0.832 g/l of ${K_2}{SO_4}$, 0.124 g/l of $CaCO_3$, 0.103 g/l of KBr, 0.0288 g/l of $SrSO_4$, and 0.0282 g/l of ${H_3}{BO_3}$. The antifreeze activity significantly increased after cells were treated with cold shock (at $-5^{\circ}C$) for 14 h. To the best of our knowledge, this is the first report demonstrating an antifreeze-like protein of C. neogracile.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.140-143
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• 2005

This study was concerned with the optimization of liquid culture conditions for mycelial growth and polysaccharide production and its physicochemical properties in Cordyceps militaris. The one factor at a time method was adopted to investigate the effects of medium composition, environmental factors and C/N ratio. Among the these varialbles, glucose 80g/L, yeast extract 10g/L, $MgSO_4{\cdot}7H_{2}O\;0.5g/L$, $KH_{2}PO_4\;0.5g/L$ were proved to be the most suitable carbon, nitrogen, and mineral sources, respectively. The optimal temperature, initial pH, working volume were identified to be $24^{\circ}C$, 7.0 and 100ml, respectively. Under the optimal conditions, the strategies in shake flask culture and 5L jar fermentor led to mycelial growth of 29.43 g/L, 28.88g/L and polysaccharide production of 2.53g/L, 6.38 g/L, respectively. Among the phisicochemical properties, relative concentrations(w/v) of total sugar, uronic acid, protein and hexoseamine were identified to be 74.07%, 1.13%, 0.91%, and 0.46%, respectively. The fraction of neutral and acidic polysaccharide were identified to be 81.9% and 18.1%, respectively.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.6-10
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• 2001

The production of chitosan from the mycelia of Absidia coerulea was studied to improve cell growth and chitosan productivity. Culture conditions were optimized in batch cultivation (pH 4.5, agitator speed of 250 rpm, and aeration rate of 2 vvm) and the maximum chitosan concentration achieved was 2.3g/L under optimized conditions. Continuous culture was carried out successfully by the formation of new growth spots under optimized conditions, with a chitosan productivity of 0.052g/L(sup)-1 h(sup)-1, which is the highest value to date, and was obtained at a dulution rate of 0.05h(sup)-1. Cell chitosan concentrations reached about 14% in the steady state, which is similar to that achieved in batch culture. This study shows that for the continuous culture of Absidia coerulea it is vital to control the medium composition.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.36-36
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• 2018

Soybean is the important crop in Asian countries as protein source, oil production and animal feed. Improving soybean using genetic transformation is the principal tool in nowadays. Developing herbicide resistant transgenic soybean plants through Agrobacterium-mediated transformation has been worked in many previous studied. However, the transformation efficiency is still low. Many attempts try to find the optimum media condition for plant regeneration after infection. After transformation, the plant regeneration is very important condition to promote growth of transgenic plant. In this study, we optimized a regeneration condition for two Korean soybean cultivar, Dawonkong and Pungsannamulkong using cotyledon, cotyledonary nodes and hypocotyl as explant. The results showed that shoot regeneration of cotyledonary nodes on B5 medium containing 2 mg/L 6-benzylaminopurine showed the highest percentage of regeneration in Dawonkong (75.8%) while Pungsannamulkong presented high number of shoots 2.12 shoots per explant. For transformation condition, co-cultivation in 7 days showed a high number of GUS positive expression. Most of explants can survived under media including 5 mg/L of glufocinate which refers phosphinotricin for 2-week selection. Washing with 400 mg/L of cefotaxime in several times and selection in plant regeneration media with 400 mg/L of cefotaxime can prevent bacteria growth, effectively.

• Journal of Life Science
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• v.21 no.9
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• pp.1205-1213
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• 2011

The optimal concentrations of salts in medium for cell growth and the production of carboxymethylcellulase (CMCase) by a recombinant E. coli JM109/DL-3 were established using two statistical methods: orthogonal array method (OAM) and response surface method (RSM). The analysis of variance (ANOVA) of data based on OAM indicated that $K_2HPO_4$ gave maximum sum of square (S) and percentage contribution (P) for cell growth as well as production of CMCase. The optimal concentrations of $K_2HPO_4$, NaCl, $MgSO_4{\cdot}7H_2O$, and $(NH_4)_2SO_4$ in medium for cell growth extracted by Qualitek-4 (W32b) Software were 10.0, 1.0, 0.2, and 0.6 g/l, respectively, whereas those for the production of CMCase by E. coli JM109/DL-3 were 5.0, 1.0, 0.4, and 0.6 g/l. The analysis of variance (ANOVA) resulting from RSM indicated that a highly significant salt for cell growth was $K_2HPO_4$ ("probe>F" less than 0.0001), whereas $K_2HPO_4$ and $MgSO_4{\cdot}7H_2O$ were significant for the production of CMCase. The optimal concentrations of $K_2HPO_4$, NaCl, $MgSO_4{\cdot}7H_2O$, and $(NH_4)_2SO_4$ for cell growth extracted by Design Expert Software were 7.44, 1.08, 0.22, and 0.88 g/l, respectively, whereas those for production of CMCase were 5.84, 0.69, 0.28, and 0.54 g/l. The optimal concentrations of salts and their influences on cell growth and production of CMCase extracted by OAM were almost the same as those by RSM. Production of CMCase by a recombinant E. coli JM109/DL-3 under optimized concentration of salts was 1.93 times higher than that by Bacillus amyloliquifaciens DL-3.

• Journal of the Korean Society of Tobacco Science
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• v.2 no.2
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• pp.20-37
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• 1980

Among the 34 strains of Nicotinophiles selected in the previous experiments, strain NCT27 identified with Pseudomonas putida and strain NCT30 identified with Arthrobacter oxydans biotype nan thus were Investigated for optimization of growth conditions for nicotine degradation and other cultural characteristics. The compositions of optimized medium were to be following: $KH_2PO_4$ 2.Ogr, KCI 5.Ogr, $MgSO_4$.$7H_2O$ 20mg, $MnSO_4$.$6H_2O$ 0.2mg, $FeSO_4$.$7H_2O$ 1.Omg, Col$^{++}$ (Cobalt Acetate),2.O$\gamma$, N1$^{++}$ (NiSO4,6H2O) 0.5$\gamma$, and yeast extract 80mg per liter. The optimum initial concentrations of nicotine for growth were 0.4% for Pseudomonas and 0.1% for Arthrobacter, respectively. The optimum temperature and pH were 3$0^{\circ}C$ and 7.0 for both of strains. The pH of culture medium of Pseudomonas was changed from acidic condition to basic one in going from the logarithmic growth phase to the stationary growth phase. In contrast with Pseudomonas, it remained constant in case of Arthrobacter. The growth of Arthrobacter was completely inhibited in the nicotine concentration of 0.7&. However, Pseudomonas could grow even in the nicotine concentration of 1.0%. Moreover, it could grow successfully in the tobacco extract media as well as media containing carbon and nitrogen sources other than nicotine. The maximum rates of nicotine degradation were to be 1.22 gr./hr./liter for Pseudomonas and 0.186 gr./hr./liter for Arthrobacter, respectively.