• Korean Journal of Microbiology
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• v.25 no.2
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• pp.148-156
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• 1987

Extracellular laccase (E.C. 1.10.3.2) from the culture filtrate of Pleurotus ostreatus was purified by ammonium sulfate precipctation, protamine sulfate precipitation, DEAE-Sephadex A-50 ion exchange chromatography and Sephadex G-100 gel permeation chromatography. The molecular weight of the enzyme was estimated by SDS-polyacrylamide gel electrophoresis to be 58,000 and the isoelectric point was 3.75. The optimum temperature for the enzyme was about $45^{\circ}C$ and the optimum pH was 6.5. The enzyme was found to be stable at temperature below $35^{\circ}C$ and rapidly inactivated at higher temperatures. Km values for ferulic acid, vanillic acid, dihydroxyphenylalanine (DOPA) were 48.6.$\mu$M, 0.52mM, and 2.73mM, respectively, which indicates that the enzyme has much higher affinity towards ferulic acid. The reaction products of the enzyme were separated by TLC and HPLC.

• KSBB Journal
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• v.13 no.1
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• pp.31-37
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• 1998

A simple method for the in vivo production of third-stage infective juveniles(IJs) of Steinernema glaseri was developed. Using Galleria mellonella larvae, only IJs can be rapidly generated inadequate quantities for field application. The nematode inoculation concentration and incubation temperature were critically important. The most effective temperature for infectivity of Steinernema glaseri IJs to Galleria mellonella larvae was 33$^\circ C$. However, the total number of menatodes harvested at 25$^\circ C$ about 66,000 IJs per larva was significantly greater than those at other temperatures. The optimal inoculation number of nematodes was 60 to 80 nematodes per host larva. The higher nematode inoculation concentration of 100 IJs per larva caused a rapid decrease in the total number of IJs harvested. As the inoculation medium pH increased, the number of IJs harvested increased and reached about 110,000 IJs per larva at pH 9.0. The pathogenicity of IJs decreased y increasing the salt concentration in the medium.

• Plant Disease and Agriculture
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• v.5 no.1
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• pp.55-57
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• 1999

Botrytis cinerea was isolated from a gray mo이 leaf lesion on persimmon in fields of Kyeonsangnam-do from 1996 to 1998, and etiological study was conducted including physiological characteristics. It formed gray mold lesion with light green color on leaves of persimmon (Diospyros kaki). The temperature range for mycelial growth was between $5^{\circ}C$ and $30^{\circ}C$ with the optimum temperatures of $20^{\circ}C$ to $25^{\circ}C$. Conidia were oviod, cylindric, and colorless and their dimensions in culture were $8.4~11.5\times7.0~8.9\mu\textrm{m}$. The optimum temperature of conidial germination was $25^{\circ}C$. Sclerotia on potato dextrose agar medium were well formed and brownish condiophores were observed with their size of $18.5~64.9\times4.5~8.0\mu\textrm{m}$. Symptoms on artificially inoculated plants were similar to those of gray mold disease on persimmon caused by Botrytis cinerea in fields.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.239-242
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• 2002

We have synthesized branched oligosaccharides (BOS) by the mixed-culture fermentation (MBOS), fructosyltransferase (FBOS) or glucosyltransferase (GBOS) with high concentration of sucrose (3M). MBOS was further modified as iron and sulfate-oligosaccharides. The modified MBOS were stable at high temperatures (up to $140^{\circ}C$) and low pHs (2 to 4). Most highly branched and modified oligosaccharide (0.34%, w/v) effectively inhibited fructose release from sucrose by Streptococcus mutans 6715 mutansucrase. FBOS, GBOS, iron-MBOS inhibited the mutansucrase activities from Streptococcus sobrinus about 46.8%, 49.2% and 43.1%, respectively. Most highly branched and modified oligo- saccharides (0.5%, w/v) effectively inhibited the fonnation of insoluble glucan and adherence of S. mutans or S. sobrinus cell in the presence of sucrose. Modified oligosaccharides affected the growth and acid production of oral pathogens. Cytotoxicity test showed that highly branched and modified oligosaccharides was non-toxic.

• 한국약용작물학회:학술대회논문집
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• 2010.10a
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• pp.509-510
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• 2010

• 한국약용작물학회:학술대회논문집
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• 2010.10a
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• pp.515-516
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• 2010

• KSBB Journal
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• v.8 no.4
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• pp.364-369
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• 1993

The biodegradability of some anionic surfactants were investigated using biological oxygen consumption measurement at different temperatures. As test surfactants, soap, alkyl sulfate (AS), alpha olefin sulfonate (AOS), alkyl polyoxyethylene sulfate (AES), linear alkylbezene sulfonate(LAS), microbial surfactants such as sophorose lipid (sopholipid) and spiculisporic acid (S-acid), were used. The test solution were incubated at $5^{\circ}C$, $18^{\circ}C$ and $32^{\circ}C$, respectively. The comparative rates of biodegradation were in accordance with the results obtained from the surface tension measurement and methylene blue method. The results of comparative blodegradabilities of the surfactants were as follows; soap, AS>AES>AOS>LAS at $18^{\circ}C$ and $32^{\circ}C$. However, at$ 5^{\circ}C$, the biodegradation rate of soap was better than other surfactants. Considering the actual environment of the river, it was concluded that the biological oxygen consumption rate method at lower temperature was more practical than the current method such as methylene blue assay with adapted shaking flask culture at $25^{\circ}C$

• Bulletin of the Korean Chemical Society
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• v.28 no.5
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• pp.800-804
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• 2007

Cyanobacterial toxins, microcystins are very potent hepatotoxins and their occurrence has been reported all over the world. They could threaten human health when toxic Microcystis occurs in water supply reservoirs. In this study, the effects of several environmental factors on production and degradation of toxins produced by cyanobacteria in Lake Soyang have been studied. A new rapid quantification method of microcystins using fluorescence for a detection signal and a lateral-flow-type immunochromatography as a separation system was used. Culture age, temperature, light intensity, pH, N-nutrient concentration, P-nutrient concentration, iron and zinc concentration were the most importantly examined factors. The toxin content was the highest on 17-18 days and at temperatures between 20℃ and 25℃, and at pH between 8.4 and 8.8.

• Journal of Microbiology and Biotechnology
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• v.8 no.3
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• pp.251-257
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• 1998

Cycloinulooligosaccharide fructanotransferase (CFTase) which produces cyclofructan from inulin was purified 332-fold from a culture broth of Bacillus macerans CFCl. The molecular mass of the CFTase was estimated to be 110 kDa by SDS-polyacrylamide gel electrophoresis and gel filtration, indicating that the enzyme has a monomer structure. The maximal level of enzyme activity was observed at pH 7.5 and $45^{\circ}C$. The enzyme was stable in the pH range 6.0 to 9.5, and at temperatures up to $45^{\circ}C$ for 1 h. The enzyme activity was completely inhibited in the presence of 0.5 mM $Ag^+\;or\;Cu^2+$ ion. None of sucrose (GF), l-kestose (GF2), or nystose (GF3) were found to be substrates for the CFTase, but inulooligosaccharides larger than nystose were attacked by the enzyme. The CFTase catalyzes not only the cyclization as the major reaction, but also disproportionation and coupling reactions involving intermolecular transfructosylation in the same manner as cyclodextrin glucanotransferase (CGTase) (EC 2.4.1.19).

• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.219-224
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• 1987

A strain of Leptospira interrogans(UM-19) was isolated in 1984 from a patient with epidemic pulmonary hemorrhagic fever. The bacteria has been characterized morphologically by a polymorphism showing spiral forms, short and long rods in culture. In order to study the biological relatedness among these forms of the bacteria, the short rods were separated from others by means of continuous sucrose density gradient centrifugation, and cultured at various temperatures such as $10^{\circ}C$, $15^{\circ}C$, $30^{\circ}C$ and $37^{\circ}C$. It was revealed that cultivation or subcultivation of the short rods has resulted in morphological changes observed by darkfield examination, silver stain, and scanning electron microscope showing spiral forms as well as short and long rods.