• Microbiology and Biotechnology Letters
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• v.18 no.3
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• pp.244-250
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• 1990

A bacterium capable of hydrotyzing raw starch was isolated from soil, which was identified as a strain of Bacillue. The effects of culture conditions and medium compositions on the enzyme production were investigated. Among tested carbon sources, soluble starch and wheat starch were most effective for the production of the enzyme, and the level of concentration for the optimal enzyme production was 0.5%. For nitrogen sources, polypeptone was best for the enzyme production, with the level of 0.5%. The enzyme was maximally produced by cultivating the organism at medium of initial pH 6.5, and temperature of $35^{\circ}C$. The enzyme was partially purified by Sepharose CL-6B gel filtration and DEAESephacel ion-exchange chromatography. The optimal pH and temperature for the enzyme reaction were 6.5 and $70^{\circ}C$, respectively. The enzyme most stable at pH 8.0, and temperature up to $60^{\circ}C$. In kinetic studies, the k, values for corn, wheat, rice and potato starch were 1.7, 1.4,2.5 and 1.090, respectively.

• Journal of Life Science
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• v.26 no.2
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• pp.198-203
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• 2016

This study aimed to isolate a novel agarase-producing marine bacterium and characterize its agarase, as agarases are known to produce biofunctional agarooligosaccharides or neo-agarooligosaccharides. A novel agar-degrading bacterium, SH-2, was isolated from the seawater of Namhae in Gyeongnam Province, Korea, and cultured in Marine agar 2216 medium. The 16S rRNA gene sequence represented 99% identity with that of the members of the Marinomonas genus; hence, the isolated bacterium was named Marinomonas sp. SH-2. The crude agarase was prepared from a culture medium of Marinomonas. sp SH-2, and exhibited maximum agarase activity at 170.2 units/l. The optimum conditions were pH 6.0 and 30℃ in 20 mM Tris-HCl buffer. The agarase activity of the bacterium was highly elevated from 20℃(42% relative activity) to 30℃(100%), and 82% activity was shown at 40℃. Its relative activities were less than 40% at over 40℃ after a 0.5 hr exposure. Relative activity was 100% at pH 6.0, while it was 72% and 48% at pH 5.0 and pH 7.0, respectively. The enzyme from Marinomonas sp. SH-2 degraded agarose to neoagarohexaose and neoagarotetraose, indicating that the enzyme is β-agarase. Thus, Marinomonas sp. SH-2 and its enzyme could be practical for applications in food, cosmetic, and medical research.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.246-249
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• 2010

Diacylglycerol (DAG) was produced from lipase by the catalyzed synthesis of soybean oil (SBO) and glyceryl monooleate (GMO) with Lipozyme TLIM (Thermomyces lanuginosa). Effects of reaction time, molar ratio and enzyme road were studied. When 2:1, 1:1 and 1:2 (SBO:GMO) molar ratios with 20% Lipozyme TLIM were applied in a 1-hr reaction, the concentrations of DAG produced were 17.8, 20.0 and 20.4 g/100 g oil, respectively. Different amounts (2, 5, 10 and 20%) of Lipozyme TLIM were used at a 1:2 (SBO:GMO) molar ratio, and the concentrations of DAG produced in a 1-hr reaction were 10.8, 14.0, 16.9 and 20.4 g/100 g oil, respectively. During a 72-hr reaction, 10.8-22.7 g/100 g oil of DAG were produced under the reaction conditions in this study.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.10
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• pp.969-982
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• 2016

Recently, the researches to discovery drug candidates from natural herbs have received considerable attention. In human body, enzyme mostly metabolize the compounds of natural herbs. In this study, we analysis the enzyme interactions using assoication mining. We get this data from BRENDA(: BRaunschweig ENzyme DAtabase) system. Based on enzyme interaction model, we divide the metabolites into substrate metabolites, product metabolites, inhibitor metabolites, and activating metabolites. We then compose substrate metabolite transaction, product metabolite transaction with each metabolites and enzyme interaction transaction with all metabolites. Also we take account of organism for each transactions. We mine frequent metabolites and patterns from six transactions using association rule mining. And we analysis the relationship among metabolites. As a result, we identify the distributions and patterns of metabolites consist in enzyme interactions. We found that metabolites include in only substrate are identified and have very low supports. This results can be useful to develop the effective metabolism prediction model for compounds of natural herbs.

• Microbiology and Biotechnology Letters
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• v.13 no.4
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• pp.321-327
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• 1985

Cultivation conditions for the production of extracellular alkaline protease by a nonpiamentation Serratia sp. and purification of the enzyme were studied. The maximum enzyme level was obtained at the beginning of stationary phase when the organism was cultured on brain heart infusion medium at $25^{\circ}C$ under aeration (gyratory shaking, 180 cycles/min). The enzyme was purified about 100 fold with 16.5％ yield by ammonium sulfate precipitation, ammonium sulfate fractionation followed by DEAE-cellulose chromatography (1st and 2nd). The purified enzyme moved as a single symmetrical peak in the analytical ultracentrifuge. The enzyme demonstrated its maximum activity at pH 8.5-9.0 and 4$0^{\circ}C$ when vitamin-free casein was used as a substrate.

• Korean Journal of Microbiology
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• v.10 no.2
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• pp.87-92
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• 1972

In order to study on the pigment and protease of Serratia marcescens, the correlation between protease activity and pigment formation was investigated. The results are as follows ; 1) The protease activity exhibitied two pH optima 6.0 and 7.5, respectively. 2) The optimal temeprature of proteolytic activity was 45.deg.C. With these-results, it is suggested that the proteolytic enzymes of Serratia masrecescens is stable at neutral pH range and more active at the high temeprature than lthat of otehr proteolytic enzymes.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.3 s.52
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• pp.265-271
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• 2005

This study is performed to investigate the effects of citrus essential oils on melanin production in B16 melanoma cells and reactive oxygen species (ROS) generation in RBL 2H3 cells. Five kinds of citrus essential oil (bergamot, grapefruit, lemmon, mandarin, petigrain) did not have any influence on DPPH radical scavenger activity, cell growth and cytotoxicity in B16 melanoma cells. In purified tyrosinase assay, both mandarin and petigrain essential oils dose-dependently inhibited its activity, but bergamot did not. In $1{\mu}M\;{\alpha}-MSH-stimulated$ B16 melanoma cells, all of 5 citrus essential oils inhibited melanin production in $\underline{a}$ dose dependent manner. On the other hand, four kinds of citrus essential oil dose-dependently increased ROS generation in RBL 2H3 mast cells, but mandarin did not. From the above results, it is possible that citrus essential oils nay be developed to be anti-melanogenic agent on the basis of their inhibitory effect on MSH-induced melanin production. Hut we can not rule out the possibility of the induction of allergy and inflammation since citrus essential oils caused ROS generation in RBL 2H3 mast cells.

• Korean Journal of Food Science and Technology
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• v.13 no.3
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• pp.241-246
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• 1981

A fungal strain which produced high levels of acid protease and amylase was isolated from the atmosphere for application to the manufacture of digestive enzme preparation. This study was carried out to elucidate its microbiological characteristics, environmental conditions for production of the enzymes, and relationships between the enzyme activity and acidity. 1. The isolate was identified as a fungal strain which belonged to Aspergillus niger by the manual of Rafer and Fennel, and was found to be a strain producing high levels of acid protease and amylase. 2. The optimal pH of tile enzymes produced by the strain were: protease, 2.0;, ${\alpha}-amylase$, 4 to 5; and glucoamylase, 3 to 5. 3. The optimal culture conditions for production of the enzymes were: protease (at pH 2.5), 2 to 3 days incubation on wheat bran at $30^{\circ}C$; ${\alpha}-amylase$ and glucoamylase(at pH 3.0), 3 days incubation at $30^{\circ}C$. 4. The production of acid protease and glucoamylase was increased approximately by 20 percent when 2 percent of corn starch was added to the wheat bran medium. 5. The addition of 0.3 percent ammonium sulfate to the wheat bran medium resulted in enhancing the enzyme production, especially of acid prctease.

• KSBB Journal
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• v.18 no.1
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• pp.8-13
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• 2003

Recombinant trehalose synthase from Thermus caldophilus GK24 showed an ability to produce trehalose from maltose. The activity of the partially purified enzyme was not influenced by most metal ions at 1 mM but was inhibited by 10 mM $Co^{2+}$, $Mn^{2+}$, and $Fe^{2+}$. Enzyme activity varied during prolonged reaction due to changes in the environmental conditions. Thus, the reaction was carried out for an extended time with optimized conditions of $45^{\circ}C$ and pH 7.0. An yield of 32.9% was reached at $60^{\circ}C$ after reaction for 22 h, and, maximum trehalose conversion (69.2%) was attained at $25^{\circ}C$. The yields obtained using enzyme dosages of 10, 25, and 50 U/g were 62.3, 62.3 and 59.0 %, respectively, though the initial conversion rate was higher when the higher dose was used. Similar profiles of trehalose production yields were observed with reaction working volumes of 10 ml to 2,000 ml.

• Korean Journal of Food Science and Technology
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• v.15 no.4
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• pp.404-408
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• 1983

Some properties of malic enzyme (EC 1.1.1.40) prepared from malate-decomposition yeast, Schizosac-charomyces japonicus var. japonicus St-3 were investigated. The activity of malic enzyme was maximum when it was cultured for 24 hours. The optimum conditions for the enzyme reaction were pH 10.0 and temperature of $25^{\circ}C$. The crude enzyme was very stable at the range of pH 7.0-8.4, and almost 50 percent of enzyme activity was lost by heating at $60^{\circ}C$ for 10 minutes. The malic enzyme activity was enhanced by the addition of $Mn^{++}$. But the enzyme activity was not affected by the addition of organic acids, amino acids and ethanol, respectively.