• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.293-297
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• 2002

The cyclodextrin glucanotransferase (CGTase) gene from Bacillus stearothermophilus NO2 was expressed in Saccharomyces cerevisiae 2805 under the adhl promoter. The CGTase was purified from S. cerevisiae 2805/pVT-CGTS. The purified enzyme exhibited a optima of activity around pH 7.0 and $65^{\circ}C$. Thermal stability of the enzyme was increased fairly as compared with the CGTase of B. stearothermophilus NO2. The conversion yield of cyclodextrin (CD) and the production ratio of $\alpha$-, $\beta$,-, ${\gamma}$-CD from starch were showed similarly aspect to the CGTase of B. stearothermophilus NO2.

• Microbiology and Biotechnology Letters
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• v.9 no.1
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• pp.7-19
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• 1981

The production of gluconic acid from glucose by the resting cell system of Aspergillus niger was studied. It was found that the conversion products from glucose by the resting cell system were markedly influenced by the pH, temperature, substrate concentration, aeration, metal ions, cultivation time and storage conditions of the resting cells. Conversion products were identified as gluconic acid by the thin layer chromatography and infrared spectrophotometry. These conversions were greatly stimulated by addition of $Mg^{++}$, and S $n^{++}$, but showed inhibitory effects by C $u^{++}$, H $g^{++}$, C $d^{++}$, A $g^{+}$ and cyanide. For the optimum cell storage, it was effective to be kept at -$25^{\circ}C$ in 0.05M phosphate buffer solution of pH 7.0. The gluconic acid production by the resting cell system was more effective than those of the fermentation with respect to cultivation time, yield, recovery and re-use of the cell.l.l.l.l.l.l.

• Journal of the Korea Society for Simulation
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• v.29 no.3
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• pp.83-91
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• 2020

To use the OneSAF model for the analysis of Defence M&S, the most critical factor is the acquisition of input data. The model user is hard to determine the input data such as the probability of hit(P_h) and the probability of kill(P_k). These data can be obtained directly by live fire during the development test and the operational test. Therefore, this needs more time and resources to get the P_h and P_k. In this paper, we reviewed possible ways to obtain the P_h and P_k. We introduced several data producing methodologies. In particular, the error budget method was presented to convert the P_h(%) data of AWAM model to the error(mil) data of OneSAF model. Also, the conversion method which can get the adjusted results from the JMEM is introduced. The probability of a hit was calculated based on the error budget method in order to prove the usefulness of the given method. More accurate data were obtained when the error budget method and the projected area from the published photo were used simultaneously. The importance of the P_h calculation was demonstrated by sensitivity analysis of the P_h on combat effectiveness. This paper emphasizes the importance of determining the P_h data and improving the reliability of the M&S system though steady collection and analysis of the P_h data.

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.398-404
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• 1991

- Ethanol production by calcium alginate-immobilized baker's yeast was studied in the continuous shaked-flask reactor (CSFR) using glucose medium as a feed. Immobilized cells were stable at 30~$37^{\circ}C$ and pH 4~8. Fermentation characteristics of immobilized baker's yeast were examined changing the initial glucose concentration employed were 50, 100 and 150 g/l, respectively. It was investigated that the influent glucose concentration and the dilution rate have an influence on the ethanol fermentation characteristics at steady state in continuous culture of immobilized baker's yeast. The optimum conditions for high ethanol productivity and low residual glucose output in ethanol prodution were shown to be 0.2 h ' for the dilution rate and 150 g/l for the influent glucose concentration. The maximum ethanol productivity, ethanol yield, specific growth rate and glucose conversion rate were around 7.12 g/$l\cdot h$, 0.23, 0.366 g/$l\cdot h$ and 78.43, respectively.

• Journal of the Korean Wood Science and Technology
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• v.38 no.3
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• pp.262-273
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• 2010

In the enzymatic hydrolysis of rice straw and wood meals using extra-cellular enzymes from Fomitopsis palustris, key factors which enhanced the sugar conversion yield were investigated in this work, such as enzyme production and enzyme reaction conditions, surfactant effects, and the surface structure of substrates. F. palustris cultured with softwood mixture produced 12.0 U/$m{\ell}$ for endo-${\beta}$-1,4-gulcanase (EG), 116.68 U/$m{\ell}$ for ${\beta}$-glucosidase (BGL), 18.82 U/$m{\ell}$ for cellobiohydrolase (CBH), and 13.33 U/$m{\ell}$ for ${\beta}$-xylosidase (BXL). These levels of BGL, CBH, and BXL activities were two to four folds more than enzyme activities of F. palustris cultured with rice straw. The optimum reaction conditions of cellulase-RS which produced by F. palustris with rice straw and cellulase-SW which produced by F. palustris with softwood mixture were pH 5.0 at $45^{\circ}C$ and pH 5.0 at $50^{\circ}C$, respectively. The sugar conversion yield of cellulase-SW had the highest value of $40.6{\pm}0.6%$ within 72 h when rice straw was used as substrate. By adding 0.1% Tween 20 (w/w-substrate), the sugar conversion yield of rice straw was increased to 44%, which was about four fifths sugar conversion yield of commercial enzyme, Celluclast 1.5L (Novozyme A/S). A low crystallinity and an intensive fibril surface observed by the scanning electron microscope may explain the high sugar conversion yield of rice straw.

• Geophysics and Geophysical Exploration
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• v.12 no.1
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• pp.105-113
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• 2009

The interpretation of observed waveform characteristics identified in refraction and wide-angle reflection data increases confidence in the crustal structure model obtained. When calculating traveltimes and raypaths, wavefront methods on a regular grid based on graph theory are robust even with complicated structures, but basically compute only first arrivals. In this paper, we develop new algorithms to compute traveltimes and raypaths not only for first arrivals, but also for fast and later reflection arrivals, later refraction arrivals, and converted waves between P and S, using the modified wavefront method based on slowness network nodes mapped on a multi-layer model. Using the new algorithm, we can interpret reflected arrivals, Pg-later arrivals, strong arrivals appearing behind Pn, triplicated Moho reflected arrivals (PmP) to obtain the shape of the Moho, and phases involving conversion between P and S. Using two models of an ocean-continent transition zone and an oceanic ridge or seamount, we show the usefulness of this algorithm, which is confirmed by synthetic seismograms using the 2D Finite Difference Method (2D-FDM). Characteristics of arrivals and raypaths of the two models differ from each other in that using only first-arrival traveltime data for crustal structure analysis involves risk of erroneous interpretation in the ocean-continent transition zone, or the region around a ridge or seamount.

• Tuberculosis and Respiratory Diseases
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• v.56 no.5
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• pp.485-494
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• 2004

Background : To assess the effects of mDOT implementation on sputum smear conversion for AFB (Acid fast bacilli) positive pulmonary tuberculosis patients, modified Directly Observed Treatment (mDOT) was started on October $8^{th}$ 2001 at a health center in Seoul. mDOT was defined through weekly interviewing and supervising of a patient by a supervisor (doctor, nurse, or lay health worker). The sputum smear conversion of a mDOT group was compared with that of a self-medication (self) group. Methods : This study included 52 AFB positive pulmonary tuberculosis patients registered at a health center in Seoul between October $8^{th}$ 2001 and April $23^{rd}$ 2002. 24 and 28 patients were enrolled in the mDOT and self medication groups, respectively. Paired (1:1) individual matching, by gender, extent of disease, relapse and age-matching variables, was performed between the two groups, resulting in 20 paired matches. This prospective study was planned as an unblinded, non-randomized quasiexperimental pilot project. Outcomes were identified from results of sputum smear examinations for AFB in both groups at 2 weeks, and 1 and 2 months. The paired matching data were analyzed using the SAS program version 8.1 by McNemar test. Results : At the end of 2 weeks of treatment, the sputum smear conversion of the mDOT group was somewhat higher than that of the self medication group (78.57 vs. 50%, p-value=0.289), and after 1 month of treatment no statistically significant difference was shown between the two groups (83.33 vs. 50, p-value=0.125). At the end of 2 months of treatment (initial intensive phase), the sputum smear conversions of the mDOT and self groups were 95 and 75%, respectively (p-value=0.219). Conclusions : The implementation of mDOT did not result in clinically significant increases in the sputum smear conversion at 2 weeks, and 1 and 2 months compared with that of the self medication group. However, the increases experienced might contribute to diminishing the infectious period of AFB positive patients, and this approach may act as a guide for a specific group of patients. In this study, mDOT was performed for one hundred percent of the intensive treatment phase. It can also be an effective treatment for pulmonary tuberculosis patients, and may be useful for some high risk tuberculosis patients.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.10a
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• pp.206.4-206
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• 1978

By utilizillg whole cell enzyme of the Xantho-monas citri IFO 3835, cephalexin is synthesized directly from 7-amino-deacetoxy cephalosporanic acid (7-ADCA) and phenyl glycine methyl ester (PGM). To date, cephalexin has been manufactu-red by chemical process involving fairly large number of steps to protect the amino group of phenly glycine and carboxyl group of 7-ADCA. However, the enzymatic process involves only a single step with 85％ conversion in 90 minutes. The fermentation variables studied indicate that oxygen transfer is limiting step in the enzyme production. Optimum conditions for enzymatic reaction were 37 C, pH 6.0, and the optimum substrate molar ratio of PGM to 7-ADCA was 2. Other variables that are related to the biochemical properties of whole cell enzyme temperature stability, pH stability, kinetic constants, reusing effect, enzyme loading effect were also evaluated.

• Food Science of Animal Resources
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• v.30 no.4
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• pp.582-589
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• 2010

The current study was designed to assess the effects of emulsified sausage supplemented with ginseng saponin on lipid metabolism by applying a rat model. Four groups of 8 rats (5 wk old) were each allocated one of 4 treatments: basal feed (C), and basal feed with 20% sausage powder containing 0% (S0), 2% (S2) and 4% (S4) ginseng saponin. The experiment was conducted for 4 wk. The results did not differ among the treatments with different amounts of sausage (ST), but daily feed intake (p<0.01) and feed conversion (p<0.001) were significantly increased in STs compared to C. Both total serum cholesterol and triglyceride concentrations were significantly (p<0.001) reduced, by 45 and 46%, and 48 and 46%, in S2 and S4, respectively, compared to S0. In the liver, the total cholesterol level was dramatically (p<0.05) decreased according to increasing sausage powder levels. In particular, S4 showed approximately 14% reduction compared to S0 (p<0.05). Liver triglyceride content also showed a similar tendency, where S2 and S4 resulted in 7% and 31% reduction. With regard to fatty acid composition in the liver tissues, palmitic acid (16:0), oleic acid (18:1), eicosanoic acid (20:1), and eicosatrienoic acid (20:3) did not differ among the STs, whereas both linoleic acid (18:2) (p<0.01) and linolenic acid (18:3) (p<0.001) showed significant increases in S2 compared to S0. The current data demonstrated that emulsified sausages supplemented with ginseng saponin effectively reduce total cholesterol and triglyceride concentrations in the serum and liver, and increase unsaturated and essential fatty acid in the liver. These data collectively imply that the sausage improved the overall lipid profile in a rat model, and can be further generalized to the result that emulsified sausage can improve lipid metabolism depending on the products' formula.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.102-108
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• 2006

The IscA gene, encoding a levansucrase of 424 amino acids (aa) residues, was cloned from the genomic DNA of Pseudomonas aurantiaca S-4380, and overexpressed in Escherichia coli. The recombinant levansucrase overexpressed in E. coli was then used to produce levan from sucrose. Levan crystals with 98% purity could be obtained from the reaction mixture with $62\%$ yield using an alcohol precipitation method. The molecular weight of the levan was $7\times10^5$ daltons. Methylation studies showed that the levan was branched: main linkage C-2,6; branched linkage C-2,1; and degree of branching $6\%$. Three bacterial levans from different strains were incubated with levan fructotransferase (LFTase) from Arthrobacter ureafaciens K2032, which produced $di-\beta-D-fructofuranose$ dianhydride IV (DFA IV); final conversion yields from the levans to DFA IV were $39\%$ in Zymomonas mobilis, $53\%$ in Serratia levanicum, and $59\%$ in P. aurantiaca S-4380 levansucrase. The levan from P. aurantiaca S-4380 levansucrase gave the highest conversion yield of levan to DFAIV so far reported.