• Korean Journal of Plant Tissue Culture
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• v.28 no.1
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• pp.53-58
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• 2001

To develop herbicide-resistant cucumber plants (Cucumis sativus L. cv Green Angle) embryogenic suspension cultures were co-cultured with Agrobacterium tumefaciens strain LBA4404 carrying a disarmed binary vector pGA-bar. The T-DNA region of this binary vector contains the nopalin synthase/neomycin phosphotransferase Ⅱ (npt Ⅱ) chimeric gene for kanamycin resistance and the cauliflower 35S/phosphinothricin acetyltransferase (bar) chimeric gene for phosphinothricin (PPT) resistance, After co-cultivation for 48 h, embryogenic calli were placed on maturation media containing 20 mg/L PPT. Approximately 200 putatively transgenic plantlets were obtained in hormone free media containing 40 mg/L PPT. Northern blot hybridization analysis confirmed the expression of the bar gene that was integrated into the genome of five transgenic plants. Transgenic cucumber plants were grown to maturity. Mature plants in soil showed tolerance to the commercial herbicide (Basta) of PPT at the manufacturer's suggested level (3 mL/L).

• Journal of Plant Biotechnology
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• v.39 no.3
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• pp.140-145
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• 2012

The flowering locus T (FT) gene, of which expression will be controlled at high temperature by heat shock promoter (it printed as to HSproFT), was introduced into spray-type chrysanthemum (Dendranthema grandiflorum (Ramat.) Kitamura) 2 cultivars ('Pink PangPang' and 'Pink Pride' by co-cultivation with Agrobacterium tumefaciens strain C58C1 harboring pCAMBIA2300 containing the HSproFT gene. After leaf segments of the 2 cultivars were infected with the A. tumafaciens with C58C1 as explants, shoots were regenerated from the explants cultured on the $1^{st}$ selection medium (MS basal salts + 1.0 mg/L BA, 0.5 mg/L IAA + 10 mg/L kanamycin + 0.7% plant agar, pH 5.8). The shoots were transferred into the $2^{nd}$ selection medium (MS basal salts + 1.0 mg/L BA, 0.5 mg/L IAA + 20 mg/L kanamycin + 0.7% plant agar, pH 5.8). One hundred seventeen plantlets from 'Pink PangPang' and 5 ones from 'Pink Pride' were confirmed as transformants by PCR analysis. Twenty six of the transformants and non-transformants were acclimatized and established well in a green house. Eights of 26 transgenic lines showed flower bud 1.7~10 days earlier than nontransgenic plants, and 24 of them flowered 1~6 days earlier than non- transgenic plants. The shape and color of flower of all HSproFT-transgenic lines were not different with those of non- transgenic plants.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.373-379
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• 2002

By using DL-acetonitrile as enzyme inducer, 90 bacteria were isolated from a field soil. Among the isolated strains, the strain WJ-003 showed the highest activity for production of D-lactic acid from DL-lactonitrile, and was partially identified as Pseudomonas sp. The production condition of D-lactic acid from DL-lactonitrile using resting cells as an enzyme source was optimized as follows: the reaction mixture contained 10 mM of DL-lactonitrile, 20 g of wet cells in 11 of 20 mM potassium phosphate buffer (pH 7.0) and the reaction was carried out at $30^{\circ}C$. After 18 h of reaction, 0.843 g/l of D-lactic acid was produced which corresponded to a conversion ratio of 93.7% and an optical purity of 99.8%. Additionally, when 10 mM of DL-lactonitrile was added once more to the reaction mixture at 14 h, 1.64 g/1 of D-lactic acid was produced after 28 h. In this experiment, the conversion ratio was 91.1% and optical purity 99.8%.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.1
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• pp.26-39
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• 2007

In recent years, rate control is an important technique in real time video communication applications using H.264/AVC. Many existing rate control algorithms employ the quadratic rate-distortion model, which is determine the target bits for each P frame. In this paper, a new rate control algorithm for transmission of H.264/AVC video bit stream through CBR(Constant Bit Rate) channel is proposed. The proposed algorithm predicts an adaptive QP(Quantization Parameter) for improving video distortion, due to high motion and abruptly scene change, which target bit rate and MAD(Mean of Absolute Difference) for current frame considering image complexity variance between previous and current frames. Additionally, it uses frame skip technique to maintain bit stream within a manageable range and protect buffer from overflow or underflow. Experimental results show that the proposed method gives a quality improvement of about 0.5dB when compared to previous rate control algorithm. Also our proposed algorithm encodes the video sequences with less frame skipping compared to the existing rate control for H.264/AVC.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.387-389
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• 1997

Effect of concentrations of wheat flour and glucose on the sponge fermentation of soda cracker by the mixed lactic acid bacteria of L. brevis, L. fermentum and L. plantarum was investigated. When glucose was added to the wheat flour solution, pH was higher and TTA (total titrable acid) was lower as compared with the medium without glucose. This results suggested that glucose in the solution stimulate cell growth but inhibit the production of organic acids. With increasing of wheat flour concentration, pH decreased and TTA increased during the sponge fermentation of soda cracker.

• Korean Chemical Engineering Research
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• v.44 no.5
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• pp.476-482
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• 2006

This paper studied the recovery of organic acid from organic acid salt by using bipolar membrane electrodialysis. Acetic acid and lactic acid was used as for organic acid. Organic acid concentration, sodium hydroxide concentration and pH values were measured at various current density. Organic acid salt was effectively converted to organic acid and sodium hydroxide. Based on the experimental results, mathematical models were developed, in which time changes in ion balance were considered. Model predictions of organic acid concentration, sodium hydroxide concentration and pH values were in good agreement with the experimental data.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.1
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• pp.78-86
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• 2012

In this study, dark fermentative hydrogen production (DFHP) from acid pretreated microalgal biomass was optimized with via statistical experimental design. Acid concentration and reaction time were varied from 0.1 to 3% (v/w) and 10 to 60 min with substrate concentration of 76 g dry cell weight (dcw)/L and initial pH of 7.4, respectively. During the fermentation, pH was not controlled. The optimal condition was found that at $H_{2}$ yield reached to 37.3 mL $H_{2}/g$ dcw at 1.2% HCl and 48 min. Through regression analysis, it was found that $H_{2}$ yield was well fitted by a quadratic polynomial equation ($R^{2}$=0.95). HCl concentration was the most significant factor influencing DFHP. The results of ANOVA verify that HCl concentration was the most significant factor influencing DFHP.

• Journal of Plant Biotechnology
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• v.33 no.1
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• pp.33-37
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• 2006

Bottle gourd (Lagenaria siceraria Standl.) has been used as a rootstock for the watermelon cultivation because of better growth ability at low temperature and avoidance from contamination of the soil disease. Since the genetic source for the elite rootstock is limited in nature, the genetic engineering method is inevitable to develop new lines especially to obtain the functionally important or multi-disease resistant bottle gourd. Recently, our lab has set up a successful system to transform the bottle gourd. in order to monitor the transformation process, GFP gene is used. Cotyledons of the inbred line 9005, 9006 and G5 were used to induce the shoot under the selection media with MS + 30 g/L sucrose + 3.0 mg/L BAP + 100 mg/L kanamycin + 500 mg/L cefotaxime + 0.5 mg/L $AgNO_3$, pH 5.8. The shoot was developed from the cut side of the explants after 3 weeks on the selection media. The shoot was incubated in the rooting media with 1/2 MS + 30 g/L sucrose + 0.1 mg/L IAA + 50 mg/L kanamycin + 500 mg/L cefotaxime, pH 5.8 and moved to pot for acclimation. Although the shoot development rate was depended on the genotype, the G5 was the best line to be transformed. Monitoring GFP expression from the young shoot under microscope could make the selection much easier to distinguish the transformed shoot from the non-transformed shoots.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.102-111
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• 2016

The goal of this study was to characterize the BrDSR (Drought Stress Resistance in B. rapa) gene and to identify the expression network of drought-inducible genes in Chinese cabbage under drought stress. Agrobacterium-mediated transformation was conducted using a B. rapa inbred line ('CT001') and the pSL100 vector containing the BrDSR full length CDS (438 bp open reading frame). Four transgenic plants were selected by PCR and the expression level of BrDSR was approximately 1.9-3.4-fold greater than that in the wild-type control under drought stress. Phenotypic characteristics showed that BrDSR over-expressing plants were resistant to drought stress and showed normal growth habit. To construct a co-expression network of drought-responsive genes, B. rapa 135K cDNA microarray data was analyzed to identify genes associated with BrDSR. BrDSR was directly linked to DARK INDUCIBLE 2 (DIN2, AT3G60140) and AUTOPHAGY 8H (ATG8H, AT3G06420) previously reported to be leaf senescence and autophagy-related genes in plants. Taken together, the results of this study indicated that BrDSR plays a significant role in enhancement of tolerance to drought conditions.

• Applied Biological Chemistry
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• v.47 no.1
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• pp.33-40
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• 2004

Thermodynamic properties of ubiquitin transient folding intermediate were studied by measuring folding kinetics in varying temperatures and denaturant concentrations. Through quantitative kinetic modeling, the equilibrium constant, hence folding free energy, between unfolded state and intermediate state in several different temperatures were calculated. Using these values, the thermodynamic parameters were estimated. The heat capacity change $({\Delta}C_p)$ upon formation of folding intermediate from unfolded state were estimated to be around 80% of the overall folding reaction, indicating that ubiquitin folding intermediate is highly compact. At room temperature, the changes of enthalpy and entropy upon formation of the intermediate state were observed to be positive. The positive enthalpy change suggests that the breaking up of the highly ordered solvent structure surrounding hydrophobic side-chain upon formation of intermediate state. This positive enthalpy was compensated for by the positive entropy change of whole system so that formation of transient intermediate has negative free energy.