• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.628-631
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• 2003

The recombinant alanine dehydrogenase (ADH) from E. coli containing Thermus caldophilus ADH was purified to homogeneity from a cell-free extract. The enzyme was purified 38-fold with a yield of 68% from the starting cell-free extract. The purified enzyme gave a single band in polyacrylamide gel electrophoresis, and its molecular weight was estimated to be 45 kDa. The pH optimum was 8.0 for reductive amination of pyruvate and 12.0 for oxidative deamination of L-alanine. The enzyme was stable up to $70^{\circ}C$. The activity of the enzyme was inhibited by 1 mM $Zn^{2+}$, 20% hexane, and 20% $CHCl_3$. However, 10 mM $Mg^{2+}$ and 40% propanol had no effect on the enzyme activity. The Michaelis constants ($K_m$) for the substrates were $50\;\mu\textrm{M}$ for NADH, 0.2 mM for pyruvate, 39.4 mM for $NH_4+$, 2.6 mM for L-alanine, and 1.8 mM for $NAD^+$.

• Journal of Microbiology and Biotechnology
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• v.9 no.2
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• pp.206-212
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• 1999

The gene orf7(oxi III) was expressed using an E. coli system in anticipation that it would encode dTDP-glucose 4,6-dehydratase which is involved in the biosynthesis of the olivose moiety of chlorothricin produced from Streptomyces antibioticus Tu99. The solubility of the expressed protein increased up to 20% under optimal induction conditions. The expressed protein was purified from the E. coli BL 21(DE3) cell lysate by a 28.5-fold purification in two chromatography steps with a 38% recovery to near homogeneity. The molecular weight and N-terminal amino acid sequence of the purified protein correlated with the predicted mass and sequence deduced from the orf7 gene. The purified protein was a homodimer with a subunit relative molecular weight of 38,000 Dalton. The expressed protein was found to exhibit dTDP-glucose 4,6-dehydratase activity and be highly specific for dTDP-glucose as a substrate. The values of K'm and V'max for dTDP-glucose were 28 $\mu$M and 295 nmol $min^{-1} (mg protein)^{-1}$, respectively. dTTP and dTDP were strong inhibitors of this enzyme.$NAD^+$, the coenzyme for dTDP-glucose 4,6-dehydratase, was tightly bound to the expressed protein.

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.283-286
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• 2008

The methylenetetrahydrofolate dehydrogenase/cyclohydrolase (MTHFDC) from the thermoacidophilic archaeon Thermoplasma acidophilum is a 30.6kDa molecular-mass enzyme that sequentially catalyzes the conversion of formyltetrahydrofollate to methylenetetrahydrofolate, with a preference for NADP as a cofactor, rather than NAD. In order to elucidate the functional and structural features of MTHFDC from archaeons at a molecular level, it was overexpressed in Escherichia coli and crystallized in the presence of its cofactor, NADP, at 295K using polyethylene glycol (PEG) 4000 as a precipitant. The crystal is a member of the monoclinic space group $P2_1$, with the following unit cell parameters: $a=66.333{\AA},\;b=52.868{\AA},\;c=86.099{\AA},\;and\;{\beta}=97.570^{\circ}$, and diffracts to a resolution of at least $2.40{\AA}$ at the synchrotron. Assuming a dimer in the crystallographic asymmetric unit, the calculated Matthews parameter $(V_M)\;was\;2.44{\AA}^3/Da$ and the solvent content was 49.7%.

• The Journal of Pediatrics of Korean Medicine
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• v.16 no.1
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• pp.21-37
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• 2002

Effect of Sunbangpaedoktang, which has been used for atopic dermatitis(AD), on the cytokine secretory function of monocyte, which was isolated and cultured from peripheral blood of AD patients, were evaluated. The results were as follows: 1. In AD patients, Sunbangpaedoktang exhibits statistically significant inhibitory effect on IL-4. 2. In AD patients, Sunbangpaedoktang exhibits statistically significant inhibitory effect on IL-5(p<0.05). 3. In AD patients, Sunbangpaedoktang exhibits statistically significant inhibitory effect on $IFN-{\gamma}$(p<0.01). 4. In sample group, comparing the cytokine concentration change rate of AD patients with that of NAD patients IL-4 AD patients exhibits statistically significant decrease(p<0.05).

• Parasites, Hosts and Diseases
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• v.54 no.6
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• pp.813-817
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• 2016

Armillifer agkistrodontis (Ichthyostraca: Pantastomida) is a parasitic pathogen, only reported in China, which can cause a zoonotic disease, pentastomiasis. A complete mitochondrial (mt) genome was 16,521 bp comprising 13 protein-coding genes (PCGs), 22 tRNA genes, 2 rRNA genes, and 1 non-coding region (NCR). A phylogenetic tree drawn with the concatenated amino acid sequences of the 6 conserved PCGs (atp6, cox1-3, and nad2) showed that A. agkistrodontis and Armillifer armillatus constituted a clade Pentastomida which was a sister group of the Branchiura. The complete mt genome sequence of A. agkistrodontis provides important genetic markers for both phylogenetic and epidemiological studies of pentastomids.

• Korean Journal of Microbiology
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• v.12 no.3
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• pp.131-137
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• 1974

It is a well-known fact that an isolation of non-sporeforming anaerobes, considered normal flora in man ordinarily but causes serious infections sometimes, is a dificult procedure because of their great oxygen sensitivity. Among the many techniques employed in clinical laboratories, despite of its high expenses, the GasPak method has been most widely used because of its relative simplicity. On the other hand, the steel wool method has gained a good reputation recently. This technique makes it possible to treat individual plate so that any single specimen can be promptly cultured anaerobically. The procedure is quite simple and the expenses are negligible. In the present study it is to compare these two methods as to their efficiency of anaerobic cultivation using 13 VPI strains of non-sporeforming amaerobic bacteria. Among the 13 species the following 11, Bacteroides fragilis ss. fragilis, B. fragilis ss. thetaiotaomicron, propionibacterium acnes, Eubacterium limosum, E. lentum, peptococcus asaccharolyticus, Pc. prevotii, Pc. magnus, peptostreptococcus anaerobius, Ps. intermedius nad Veillonella parvula, grew well with the steel wool method whose colony numbers reaching 57 to 119% of those with GasPak method. The remaining two species, Fusobacterium nucleatum and F.necrophorum, did not grow well with the steel wool method showing the colony numbers were only 0.4% of those with GasPak method in the case of Fusobacterium nucleatum. In the case of Fusobacterium necrophorum, very few colonies developed even with a heavy inoculation. As to the size of colonies, there were no significant difference between these two methods.

• Korean Journal of Microbiology
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• v.12 no.4
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• pp.180-187
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• 1974

Of the Asp. spp. isolated by the Institute of Applied Microbiology, Kon-Kuk University, 7 strains were selected for the study of the immunological differencences among them using gel precipitation test. The strains were the following types : 1 type of flavus and 2 types of oryzae were isolated from Meju ; 1 type of flavus from Nuruk ; and each one type of flavus, parasiticus and oryzae from Kokja.Asp.flavus from ATCC, Asp. parasiticus nad Asp. niger NRRL strains were also used in the study as a standard. From this study, several points can be raised ; 1) There was no common antigenic property between Asp. niger and Asp. flavus, because of no formation of reaction line. Therefore, all strains could be easily distinguished. 2) There was common antigenic property, that is, the formation of reaction line between Asp. flavus and Asp. parasticus. Accordingly two strains could not be easily distinguished by the gel precipitation test. 3) Each type of oryzae, parasiticus and flavus of Asp. flavus group had common antigen one another as well as specific antigens only in the difference of the reaction lines, so they could be easily identified in the gel precipitation test. 4) Each isolated strain from Meju and Nuruk appeared to be identical. 5) It was shown that the gel precipitation test of serological methods was very useful for the classification of Asp. spp.

• Korean Journal of Microbiology
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• v.21 no.3
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• pp.163-169
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• 1983

Effects of temperature on the gorwth characteristics and the chemical composition of pseudomonas cells grown under glucose-or methanol-utilizing continuous culture were studied. In a glucose-utilizing continuous culture, optimum dilution rate, agitation, pH, and temperature, for the higher biomass yield were $0.45hr^-$, 7000rpm, pH 7.5, and $30^{\circ}C$, respectively. But in a methanol-utilizing continuous culture, they were $0.125hr^-$, 600rpm, pH 8, and $30^{\circ}C$, respectively. In methanol-utilizing continuous culture, the maximum production rate of the cells was 1.48g, dry wt./1/hr at a dilution rate of $0.45hr^-$, and the cell yield was 0.46g. dry wt./g. glucose. In the methanol-utilizaing continuous culture, the maximum production rate of the cells was 0.33 7g. dry wt./1/hr. at a dilution rate of $0.125hr^-$ and the cell yield was 0.44g dry cell/g. methanol. The contents of protein of the cells increase with the increase ingrowing temperature (from 15 to $30^{\circ}C$), more or less, while the contents of RNA nad carbohydrate of the cells decreased. However, DNA contents of cells growth under the various temperature ranges didn't change. As the temeprature of cultivation rises at a constant dilution rate, the efficiency of RNA in protein synthesis was increased, showing the decreases in the ratio of RNA to protein.

• Korean Journal of Microbiology
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• v.21 no.3
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• pp.143-148
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• 1983

The occurrence of PZ-peptidase in Streptococcus sanguis and other oral bacteria was investigated utilizing washed whole cells as the enzyme source and PZ-pentapeptide as its substrate. Under the culture conditions employed in the present study. Streptococcus sanguis strains, fresh isolates as well as laboratory strains, produced a broad range of the enzyme activity (0.5-7.9 unit/mg protein). The strains of both Streptococcus mutans and Lactobacilli showed low levels of activity (0-0.5 unit/mg protein for S. mutans). As compared with the enzyme activities of other bacteria, a moderate range of activity was produced by the strains of Strptococcus mitis nad Strptoccus salivarius. Actinomyces strains, like those of S. sanguis, produced a varying amount of activity (0-9.8 unit/ mg protein). A possible involvement of the oral bacterial PZ-peptidase in the metabolism of human saliva proteins is discussed.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.3
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• pp.37-45
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• 2000

The technique of laser sheet beam has been applied to optically accessible diesel engine for the quantitative measurement of soot. The results provide the information for us for reduction of soot in diesel engine. We used both LIS nad LII techniques simultaneously in this study. LIS and LII images show the quantitative distribution of the soot concentration in an optically accessible diesel engine. In this study, several results were obtained by the simultaneous measurement of LIS and LII technique. The diameter and number density of soot in combustion chamber of the test engine were obtained from ATDC 20$^{\circ}$ to 110$^{\circ}$ . The increase rate of soot diameter was about 40$^{\circ}$ between ATDC 20$^{\circ}$and 110$^{\circ}$. And the number density of soot decreased significantly between ATDC 20$^{\circ}$and 40$^{\circ}$.