• Microbiology and Biotechnology Letters
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• v.51 no.2
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• pp.203-207
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• 2023

The N₂O-reducing rhizobacterium, Pseudomonas sp. M23, was isolated from maize rhizosphere soil. The maximum N₂O reduction rate of the strain M23 was 15.6 mmol·g-dry cell weight^-1·h^-1. Its N₂O reduction activity was not inhibited by diesel contaminant, and it was enhanced by the addition of the root exudates of maize and tall fescue. The remediation efficiency of diesel-contaminated soil planted with maize or tall fescue was not inhibited by inoculating with the strain M23. Root weights in the soil inoculated with the strain M23 were greater than those in the non-inoculated soil. These results suggest that Pseudomonas sp. M23 is a promising bacterium to mitigate N₂O emissions during the remediation of diesel-contaminated soil.

• Journal of Radiation Industry
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• v.8 no.2
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• pp.105-109
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• 2014

This study was conducted to investigate the sensitivity of Arthrobacter sp. PAMC 25486 to various mutagens. ${\gamma}-ray$, UV-ray, Ethyl methane sulfonate (EMS) and hydrogen peroxide ($H_2O_2$) were used as mutagen, and the survival rate of Arthrobacter sp. was measured at various doses of ${\gamma}-ray$ and UV-ray, and concentrations of EMS and $H_2O_2$. Decimal reduction dose ($D_{10}$ value) of Arthrobacter sp. was determined 370 Gy for a gamma irradiation treatment, 0.019 J for a UV ray, 2.5 mM for EMS, and 230 mM for $H_2O_2$. This result will be applied for the development of superior mutant strain of Arctic bacteria producing valuable compounds.

• Journal of The Korean Dental Society of Anesthesiology
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• v.12 no.1
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• pp.17-23
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• 2012

Background: This study evaluated pulp vitality of anterior permanent teeth using pulse oximetry (PO), which is already used for monitoring of patient's $SpO_2$ and pulse rates (PR). Also we compared with ice tests and electric pulp test (EPT). Methods: 9 teeth, endodontic treated, were selected as non-vital teeth group. 17 vital teeth were selected as control group. Our aim is to compare sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of ice test, electric pulp test and pulse oximetry, respectively. Pulse oximetry has two test results, $SpO_2$ and pulse rates. Also we calculated correlation and statistical significances by Pearson's test between EPT and pulse oximetry. Results: Sensitivity, specificity, PPV, NPV were calculated on each tests. Ice test has results of 1.00, 0.89, 0.94 and 1.00, respectively. EPT has results of 0.94, 0.78, 0.89 and 0.88 respectively. $SpO_2$ has results of 0.94, 1.00, 1.00 and 0.90, respectively. PR has results of all 1.00. Conclusions: PO showed relatively accurate, stable and objective results on both $SpO_2$ and PR. Percentage of ability of accurate diagnosis for vital teeth is 94% for ice test, 89% for EPT, 100% for $SpO_2$ and PR. Percentage of ability of accurate diagnosis for non-vital teeth is 100% for ice test, 88% for EPT, 90% for $SpO_2$ and 100% for PR. In additions, PR could be more accurate and significant tests than $SpO_2$.

• Microbiology and Biotechnology Letters
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• v.39 no.3
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• pp.245-251
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• 2011

[ ${\alpha}$ ]Galactosidase was purified from a culture filtrate of Mortierella sp. by CM-sephadex C-50, and subsequent Sephadex G-100 column chromatography. The final preparation thus obtained showed a single band on SDS-polyacrylamide gel electrophoresis. The molecular weight was determined to be 56 kDa. $Gal^3Man^4$ ($6^3$-mono-O-${\alpha}$-D-galactopyranosyl-4-O-${\beta}$-D-mannotetraose), $Gal^{2,3}Man_5$ ($6^{2,3}$-di-O-${\alpha}$-D-galactopyranosyl-4-O-${\beta}$-D-mannopentaose), $Gal_2Man_3$ ($6^2$-mono-O-${\alpha}$-D-galactopyranosyl-4-O-${\beta}$-D-mannotriose), $Gal^2Man_6$ ($6^2$-mono-O-${\alpha}$-D-galactopyranosyl-4-O-${\beta}$-D-mannohexaose) and $Gal^2Man_5$ ($6^2$-mono-O-${\alpha}$-D-galactopyranosyl-4-O-${\beta}$-D-mannopentaose), prepared from 3 types of microbial ${\beta}$-mannnanase, were used as substrates. $Gal^3Man_4$ and $Gal^2Man_3$ had a stubbed ${\alpha}$-galactosyl residue on the $2^{nd}$ and $3^{rd}$ mannose from the reducing end of mannotetraose and mannotriose, thus ${\alpha}$-galactosidase showed a preference for stubbed ${\alpha}$-galactosyl residue. ${\alpha}$-Galactosidase hydrolyzed $Gal^3Man_4$ more rapidly than $Gal^2Man_3$. However, ${\alpha}$-galactosidase hardly acted on $Gal^{2,3}Man_5$, $Gal^2Man_6$ or $Gal^2Man_5$. The enzyme hydrolyzed melibiose to galactose and glucose, raffinose to galactose and sucrose, and also stachyose to galactose and raffinose.

• Applied Chemistry for Engineering
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• v.29 no.1
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• pp.62-66
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• 2018

Styrenated phenol alkoxylates (SP-A) were prepared from styrenated phenol (SP) and ethylene oxide (EO) under a homogeneous base catalyst. However, to use EO that is difficult to handle, a high-pressure reaction device capable of controlling the reaction process should be used. Additionally, when a homogeneous base catalyst is used, a neutralization process is required to remove residual bases after the reaction, and it is also difficult to separate the catalyst and the product. Therefore, in this study, we report the results of SP-A prepared from the reaction of SP and EC using only heterogeneous base catalysts. The heterogeneous base catalyst was obtained by supporting KOH on $La_2O_3$ and calcintion. Using EC instead of EO, it was possible to produce SP-A under the atmospheric rather than high-pressure reaction condition. Average molecular weights of synthesized SP-A varied greatly depending on reaction conditions. The average molecular weight of SP-A prepared using the $KOH/La_2O_3$ catalyst could be controlled arbitrarily by controlling the reaction temperature and added catalyst and EC amounts.

• Animal Systematics, Evolution and Diversity
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• v.23 no.2
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• pp.209-211
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• 2007

A new marine sponge in the family Microcionidae, Ophlitaspongia yongjeongensis n. sp. is collected from Yongjeong-ri, Hyeongyeong-myeon, Muan-gun, Korea during 2005-2007. O. yongjeongensis n. sp. is closely related to O. reticulata in growth form (shape and color). However, the thick style and slender style of O. yongjeongensis n. sp. are larger than O. reticulata's (Bergquist and Fromont, 1988).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.507-510
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• 2000

The purpose of this study is to research and developV$_2$O$_{5}$-SP270 composite electrode for supercapacitor. Property of an electrical double layer capacitor depend both on the technique used to prepare the electrode and on the current collector structure. The study is to research that V$_2$O$_{5}$-carbon composite electrode for supercapacitor with different voltage range. Suprcapacitor cell of V$_2$O$_{5}$-SP270 composite electrode with 25PVDFLiC1O$_4$PC$_{10}$ polymer electrolyte bring out good capacitor performance below 3V. The discharge capacitance of SP270 in 1st cycles was 13F/g at 0.1mA/cm$^2$, 3V. We performed cycle voltammogram, charge/discharge property.y.rty.y.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.49-56
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• 2000

The 2-O-$\alpha$-D-glucopyranosyl L-ascorbic acid (AA-2G) which was enzymatically glucosylated with the cyclodextrin glucanotransferase (CGTase) [EC 2.4.1.19] from Bacillus sp. JK-43 has been reported previously. The presnet experiments examined the optimal conditons for the productio of AA-2G from AA and soluble starch, and characterized the properties of the CGTase from Bacillus sp. JK-43. The reaction mixture for the maximal production of AA-2G was followings; 12% total substrate concentration, 1,400 usits/mL of CGTase and a mixing ratio of 2 : 3(g or AA : g of soluble starch). Under this condition, 1.76mM of AA-2G, which corresponded to 2.53% yield based on AA, was produced after incubation for 24hrs at 45$^{\circ}C$ (pH 5.5). The optimum pH and temperature for the CGTase activity were 6.0 and 45$^{\circ}C$, respectively. The enzyme was stable at pH 5.5 to 9.5, and at temperature up to 5$0^{\circ}C$. The thermostability of the enzyme could be enhanced up to 6$0^{\circ}C$ by the addition of 30mM CaCl2.

• Korean Journal of Microbiology
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• v.33 no.3
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• pp.187-192
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• 1997

The strain producing biosurfactant was isolated from soil. The isolated strain was identified as the genus Tsukamurella through its morphological, cultural, physiological, menaquinone type, fatty acid composition characteristics. The highest biosurfactant production by Tsukamurella sp. 26A was observed after 4 days cultivation in the culture medium containing n-hexadecane 7%, $NaNO_{3}$ 0.2%, $K_2HPO_4$ 0.001%, $MgSO_{4}$ center dot $7H_{2}O$ 0.02%, $CaCl_2$ center dot $2H_{2}O$ 0.02%, yeast extract 0.02%(pH 6.8-7.0, 30^{\circ}C.$ The surface and interfacial tension of an aqueous solution reached 30 mNim and 1.5 mNim, respectively. The biosurfactant stabilized oil-in-water emulsion with a variety of hydrocarbons, edible oils and petroleum oils.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.275-281
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• 2004

Our previous research has demonstrated that the bacterium, Pseudomonas sp. NFQ-l capable of utilizing quin­oline (2,3-benzopyridine) as the sole source of carbon, nitrogen, and energy was isolated and characterized [Yoon et ai. (2003) Kor. J. Biotechnol. Bioeng. 18(3):174-179]. In this study, we have found that Pseudomonas sp. NFQ-l could degrade quinoline as well as benzoate, and extended this work to characterize the catechol 1,2­dioxygenase (C1,2O) purified from the bacterium cultured in benzoate media. Initially, C1,2O has been purified by ammonium sulfate precipitation, gel permeation chromatography, and Source 15Q. After Source 15Q, puri­fication fold was increased to approximately 14.21 unit/mg. Molecular weight of C1,2O was about 33 kDa. Physicochemical characteristics (e.g., substrate specificity, Km, Vmax, pH, temperature and effect of inhibitors) of purified C1,2O were examined. C1,2O demonstrated the activity for catechol, 4-methylcatechol and 3-meth­ylcatechol as a substrate, respectively. The Km and Vmax value of C1,2O for catechol was 38.54 ${\mu}M$ and $25.10\;{\mu}mol{\cdot}min^{-1}{\cdot}mg^{-1}.$ The optimal temperature of C1,2O was $30^{\circ}C$ and the optimal pH was approximately 8.5. Metal ions such as $Ag^+,\;Hg^+,\;Ca^{2+},\;and\;Cu^{2+}$ show the inhibitory effect on the activity of C1,2O. N-terminal amino sequence of C1,2O was analyzed as ^1TVKISQSASIQKFFEEA^{17}.$ In this work, we found that the amino acid sequence of NFQ-l showed the sequence homology of 82, 71, 59 and $53\%$ compared with C1,2O from Pseudomonas aeruginosa PA0l, Pseudomonas arvilla C-1., P. putida KT2440 and Pseudomonas sp. CA10, respectively.