• Journal of Plant Biotechnology
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• v.1 no.1
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• pp.1-7
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• 1999

Large-scale cultures of plant cell, tissue, and organ have been achieved by using BTBB. When different sized BTBBs (5 L, 20 L, 100 L, 300 L, and 500 L) were tested for the culture of yew cells (Taxus cuspidata Sieb. et Zucc.), cell growth increment reached to 94.5% in SCV after 24 days of culture with 30% of inoculation cell density. However, there were some variations in the production of taxol and its derivatives among the BTBBs of different size. Approximate 4 ㎎/l of taxol and 84 ㎎/l of total taxanes were obtained by using a 500L BTBB after 6 weeks of culture. With a 20L BTBB, about 20,000 cuttings of virus-free potatoes (cv. Dejima) could be obtained by inoculating 128 explants and maintaining 8 weeks under 16 hr light illumination. The frequency of ex vitro rooting of the cuttings revealed as more than 99% under 30% shade. By incorporating two-stage culture process consisting of multiple bulblet formation in solid medium and bulblet development in liquid medium, mass propagation of lily through bioreactor seemed to be possible. In the case of 'Marcopolo', the growth of mini-bulblets in BTBB was nearly 10 folds faster than that of the solid medium. Time course study revealed that maximum MAR yield of ginseng (Panax ginseng C. A. Meyer) in a 5 L and 20 L BTBB after 8 weeks of culture was 500 g and 2.2 ㎏, respectively. By cutting the MAR once and/or twice during the culture, the yield of root biomass could be increased more than 50% in fresh weight at the time of harvest. With initial inoculum of 500 g of sliced MAR in a 500 L BTBB, 74.8 ㎏ of adventitious root mass was obtained after 8 weeks of culture. The average content of total ginseng saponin obtained from small-scale and/or pilotscale BTBBs was approximately 1% per gram dry weight. Based on our results, we suggest that large-scale cultures of plant cell, tissue, and organ using BTBB system should be quite a feasible approach when compared with conventional method of tissue culture.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.4
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• pp.117-124
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• 2016

Stress is resistance to stimuli to destroy a balance of mind and body in order to maintain an original steady state : A type of response and avoidance. Mild stress, which happens in tension, has a positive effect to improve concentration, but most of stress is likely to be a main factor to damage health. This is because it causes physical ailments and psychological diseases (e.g., depression, anger, frustration, loneliness, and anxiety). The purpose of this study is to analyze the difference between two groups, daytime and night university students, on ego-state, stressors, and stress coping types to improve their academic achievement by reducing their stress. There were 266 university students, who participated in a survey from November 30, 2015 until September 30, 2016. The study employed three measuring instruments : Ego-gram, stressor scale, and stress coping type scale. All the collected data were analyzed through regression analysis and t-test. The results of the regression analysis showed no significant differences in ego-state, stressors, and stress coping types between two groups. However, the results of t-test showed significant difference between the two groups : In terms of ego-state, a CP (Critical Parent) average of the night university students was significantly higher than the daytime university students'. Also, there is a significant difference in employment, future issues, and economic issues : the daytime university students considered employment and future issues more serious, while the night university students had more mental burdens of economic issues. When it comes to coping stress types, there was no significant difference between the two groups.

• KSBB Journal
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• v.21 no.3
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• pp.188-193
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• 2006

A new type of biofilter, a rotating drum biotrickling filter(RDBF), was developed and operated for the removal of styrene from industrial waste gas. The porous polyurethane foam sheet was used as a packing materials for the RDBF and a pure culture of Gram-positive bacterium Brevibacillus sp. SP1 was used as an inoculum. The reactor showed a short start-up period of 18 days, during which uniform biofilms were developed on the packing. During a steady operation at an incoming styrene concentration of $200ppm_v$ and a retention time of 0.5 min, a high and stable removal of styrene over 95% was observed. The maximum elimination capacity was estimated to be $125g/m^3{\cdot}hr$. The outstanding performance was attributed to an efficient gas-liquid mass transfer and the appropriate supply of nutrient solution to the biofilm microorganisms on the packing by the rotation of the drum.

• Journal of Microbiology and Biotechnology
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• v.29 no.3
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• pp.410-418
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• 2019

To investigate a novel ${\beta}$-glucosidase from Bifidobacterium breve ATCC 15700 (BbBgl) to produce compound K (CK) via ginsenoside $F_2$ by highly selective and efficient hydrolysis of the C-3 glycoside from ginsenoside Rd, the BbBgl gene was cloned and expressed in E. coli BL21. The recombinant BbBgl was purified by Ni-NTA magnetic beads to obtain an enzyme with specific activity of 37 U/mg protein using pNP-Glc as substrate. The enzyme activity was optimized at pH 5.0, $35^{\circ}C$, 2 or 6 U/ml, and its activity was enhanced by $Mn^{2+}$ significantly. Under the optimal conditions, the half-life of the BbBgl is 180 h, much longer than the characterized ${\beta}$-glycosidases, and the $K_m$ and $V_{max}$ values are 2.7 mM and $39.8{\mu}mol/mg/min$ for ginsenoside Rd. Moreover, the enzyme exhibits strong tolerance against high substrate concentration (up to 40 g/l ginsenoside Rd) with a molar biotransformation rate of 96% within 12 h. The good enzymatic properties and gram-scale conversion capacity of BbBgl provide an attractive method for large-scale production of rare ginsenoside CK using a single enzyme or a combination of enzymes.

• Publications of The Korean Astronomical Society
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• v.15 no.spc2
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• pp.1-13
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• 2000

Through the coupling between the near-earth space environment and the polar ionosphere via geomagnetic field lines, the variations occurred in the magnetosphere are transferred to the polar region. According to recent studies, however, the polar ionosphere reacts not only passively to such variations, but also plays active roles in modifying the near-earth space environment. So the study of the polar ionosphere in terms of geomagnetic disturbance becomes one of the major elements in space weather research. Although it is an indirect method, ground magnetic disturbance data can be used in estimating the ionospheric current distribution. By employing a realistic ionospheric conductivity model, it is further possible to obtain the distributions of electric potential, field-aligned current, Joule heating rate and energy injection rate associated with precipitating auroral particles and their energy spectra in a global scale with a high time resolution. Considering that the ground magnetic disturbances are recorded simultaneously over the entire polar region wherever magnetic station is located, we are able to separate temporal disturbances from spatial ones. On the other hand, satellite measurements are indispensible in the space weather research, since they provide us with in situ measurements. Unfortunately it is not easy to separate temporal variations from spatial ones specifically measured by a single satellite. To demonstrate the usefulness of ground magnetic disturbance data in space weather research, various ionospheric quantities are calculated through the KRM method, one of the magneto gram inversion methods. In particular, we attempt to show how these quantities depend on the ionospheric conductivity model employed.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.5
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• pp.432-443
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• 2005

Microarray technology has contributed Significantly to the understanding of bacterial genetics and transcriptional regulation. One neglected aspect of this technology has been optimization of microarray-generated signals and quality of generated information. Full genome microarrays were developed for Clostridium acetobutylicum through spotting of PCR products that were designed with minimal homology with all other genes within the genome. Using statistical analyses it is demonstrated that Signal quality is significantly improved by increasing the hybridization volume. possibly increasing the effective number of transcripts available to bind to a given spot, while changes in labeled probe amounts were found to be less sensitive to improving signal quality. In addition to Q-RT-PCR, array validation was tested by examining the transcriptional program of a mutant (M5) strain lacking the pSOL1 178-gene megaplasmid relative to the wildtype (WT) strain. Under optimal conditions, it is demonstrated that the fraction of false positive genes is 1% when considering differentially expressed genes and 7% when considering all genes with signal above background. To enhance genomic-scale understanding of organismal physiology, using data from these microarrays we estimated that $40{\sim}55%$ of the C. acetobutylicum genome is expressed at any time during batch culture, similar to estimates made for Bacillus subtilis.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.3
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• pp.241-250
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• 2006

In the present study, a beach survey such as sand sizes, swim zone widths, and slopes of swash zone has been accomplished for 39 beaches along the Gangwon coastline. The data analysis presents that the swim zone width has a strong correlation with the sand size, showing that the swim zone width is reversely proportional to the 1.1 power of a grain size. The profile factor A has been analyzed using the beach profile form of $h=Ay^{2/3}$, where A was resulted to be proportional to the 0.77 power of a gram size.

• International Journal of Safety
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• v.9 no.1
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• pp.6-11
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• 2010

Thermal analysis, heating test on gram scale and simulation of exothermic behavior based on kinetic analysis has been conducted in order to evaluate thermal hazards of self-polymerization of MDI. The exothermic reactions of MDI are expected to be the polymerization which forms carbodiimide and carbon dioxide, dimerization and trimerization. When MDI is kept in adiabatic condition during 1 week (10080 hours), the simulated result shows runaway reaction can occur in the case that initial temperature was more than $130^{\circ}C$. The relationship between the initial temperature (T, $^{\circ}C$) and TMR is given in a following equation. TMR=$4.493{\times}10^{-7}$ exp ($9.532{\times}10^3$/(T+273.15)) We propose that the relationship gives important criteria of handling temperature of MDl to prevent a runaway reaction.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.643-648
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• 2002

For wastewater treatment and utilization of the biomass, a photosynthetic bacterium was isolated based on its cell growth rate, cell mass, and assimilating ability of organic acids. The isolate was a Gram-negative rod-shaped bacterium that contained a single polar flagellum and formed a lamellar intracytoplasmic membrane (ICM) system, including bacteriochlorophyll $\alpha$. The major isoprenoid quinone component was identified as ubiquinone Q-10, and the fatty acid composition was characterized as to contain relatively large amount of C-16:0 (18.74%) and C-18:1 (59.23%). Based on its morphology, phototrophic properties, quinone component, and fatty acid composition, the isolate appeared to be closely related to the Rhodopseudomonas subgroup of purple nonsulfur bacteria. A phylogenetic analysis of the isolate using its 16S rRNA gene sequence data also supported the phenotypic findings, and classified the isolate closely related to Rhodopseudomonas palustris. Accordingly, the nomenclature of the isolate was proposed as Rhodopseudomonas palustris KUGB306. A bench-scale photosynthetic bacteria (PSB) reactor using the isolate was designed and operated for the treatment of soybean curd wastewater.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1268-1273
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• 2011

The present study was conducted to determine a feasible method of protein concentrate extraction from rice bran (RBPC) and its effect as a substitution for skim milk in early weaning pig diets. An investigation to extract protein concentrate from full fat rice bran was undertaken to determine the best ratio of water and rice bran, the amount of NaOH and a HCl solvent to use in a simple paddle-type mixer with modified spinning to produce RBPC. The results stated that the best ratio for water mixing in the RBPC extraction process was 1:5 with 20 g NaOH and 30 min in a paddle-type mixer at 300 rpm. A mix of 250 ml 0.2 N HCl was optimum for neutralization and protein precipitation. After the fluid was spun out with a washing machine, the sediment was left for 12-14 hours to complete the filtration. One kilogram of rice bran could produce an average of 324.5 gram RBPC and it contained 3.40% ash, 496.48 kcal of GE/100 gram, 1.94% crude fiber, 28.20% ether extract, 7.64% moisture and 16.66% crude protein, respectively. A total of 45 crossbred piglets, weaned at 3 weeks of age were allotted into control diet (A) and dietary treatments formulated with a four different rates of RBPC substitution for skim milk at a percentage of 25 (B), 50 (C), 77 (D) and 100 (E) respectively, in a randomized complete block (RCB) design. All piglets had free access to feed and water until 8 week of age when the experiment ended. Feed intake, average daily gain, growth rate and feed efficiency were not affected by dietary treatments. Blood test parameters after completion of the growth trial indicated normal health. Even though the mean of cell hemoglobin concentration was significantly different between treatments (p<0.05) it was still within the normal range. The cost difference for BW gain of 100% RBPC substituted for skim milk in the weaning diet was approximately 35% lower than that of the control and the relative cost of production was 96.67, 92.85, 70.75 and 64.48% lower for the replacement of 25, 50, 75 and 100% of skim milk respectively. These results implied that this technology is feasible for use by small scale farmers to improve their self-reliance.