• Journal of Sericultural and Entomological Science
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• v.18 no.2
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• pp.89-93
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• 1976

The physiological saline solution for animals is known as Ringer's solution which is used for keeping the function of cold blooded vertebrate animals. Primaily the saline solution is used for the purpose of perfusion experiment in frogs. Later the saline solution is applied in several kinds of animals including human being with satisfactory results. However, this saline solution was introduced to silkworm and it was found that the result was not as successful as in the case of other animals and human being. Normally, in the case of silkworm, the physiological saline solution is prepared in order to maintain the normal function of separated organs and tissues. To this end, the saline solution is adjusted to contain the certain amount and strength of ions, osmosis pressure and hydrogen concentration. The most of cases, the physiological saline solution should be prepared so that the constituent of the solution be the same with the blood selium and body fluid. The hydrogen concentration in the ion element of the saline solution is adjustable by adding Na$\^$＋/, K$\^$＋/, Ca$\^$＋＋/, Mg$\^$＋＋/ which are followed by adding of buffer solution such as NaHCO$_3$and NaH$_2$PO$_4$. Determination of optimum concentration of cation in the physiological saline solution, and the optimum mixing rate of more than two kinds of cations are based on the movement of dorsal vessel in the silkworm larvae. The optimum concentration of cations in the solution is prepared by adding NaCl solution which is under zero point. However, this solution was further added with the different concentration of KCl and CaCl$_2$. By dropping the prepared solution on the 5th larvae, the effects of solution was measured. The measurement was done by observation of movement' of dorsal vessel and its time length, and the number of pulses. According to the experiment, it was found that when only NaCl solution was applied, the number of pulses is increased for a moment, and the pulse stopped after one hour or so. When KCl solution was added the time of pulse was prolonged and in the contrast, the number of pulses was slow down. If KCl and CaCl$_2$solutions are added the time of pulse was further prolonged. Even though the adding of KCl and CaCl$_2$are found to be effectible, the correlation between the concentration of solution and the movement of dorsal vessel was not observed. However, it was same in the case of adding Ca$\^$＋＋/ or K$\^$＋/. It was found that when Mg$\^$＋＋/ was added to dorsal vessel the number of the pulses was not decreased although the prolonged time pulse was observed.

• Microbiology and Biotechnology Letters
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• v.9 no.1
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• pp.35-44
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• 1981

Whole cell penicillin amidase of Escherichia coli was immobilized by entrapment in gelatin followed by extrusion and crosslinking with glutaraldehyde. The immobilized engyme preparation demonstrated the recovery yield of activity up to 70% and good stability during storage and operation. The half life of activity decay during the operation was estimated to be about 50 days. The optimum pH and temperature for both of immobilized and soluble enzyme are 8.5 and 5$0^{\circ}C$, respectively. No significant change was demonstrated in the effect of pH and temperature, but the increase in heat stability at high temperature was observed in the case of the immobilized enzyme. It was found that the plug flow reactor could be operated favorably since the pH drop along the column path due to tile reaction product was minimized by employing substrate solution with moderate buffer strength. The optimal condition of reactor operation was discussed with regard to the effect of substrate concentration and the residence time on the conversion efficiency and productivity.

• Microbiology and Biotechnology Letters
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• v.8 no.4
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• pp.229-235
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• 1980

Pectin transeliminase (PTE) was produced by Saccharomyces cerevisiae, Schizosaccharomyces pombe 4683, and Aspergillus niger in the media containing 2% pectin and examined for its characteristics. The Production of the enzyme was higher by Asp. niger than by the two yeast strains, showing that the PTE activity was proportional to reducing power. The enzyme was proved to reduce pectin and produce 4, 5- unsaturated galacturonic acid. The optimum activity of the PTE was found to be at pH 6.0 and $50^{\circ}C$. The activities of these enzyme were stable below $50^{\circ}C$ but decreased at the higher temperature. Substrate inhibition of the PTE activities was appeared at high concentrations of pectin. Those PTE activities were increased under 0.6M of KCI and NaCI, but that maximal activities at the concentration of 0.2M MgC $l_2$.

• Microbiology and Biotechnology Letters
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• v.8 no.1
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• pp.9-18
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• 1980

During an extensive screening tests of yeasts for their RNA formation, it was found that Cryptococcus laurentii had especially high RNA content and high dry cell weight, when hydrolyzate of sliced and dried sweet potatoes was used as a carbon source. Growth conditions of this strain were examined, and the most desirable results were obtained at 48 hours of cultivation on a reciprocal shaker at 3$0^{\circ}C$ with initial pH 6.0. Under the above conditions, the RNA content and yield of dry cells were investigated using various media compositions. Ammonium sulfate 0.40%, peptone 0.6 ％, and yeast extract 0.4% were appeared to be favorable as a nitrogen sources. The optimum concentrations of K $H_2$P $O_4$, M $n^{++}$, C $O^{++}$ were 0.05 ％, 0.1 ％, and 0.001 ％, respectively. Ca-pantothenate, 400$\mu\textrm{g}$/$m\ell$, showed relatively favorable effects as a growth factor. The maximum RNA content obtained in this study was 16.8 ％ of the total dry cell weight.t.t.

• Journal of Microbiology and Biotechnology
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• v.8 no.6
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• pp.560-567
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• 1998

We have found that Thermoactinomyces vulgaris KFB-Cl00 produces a chitinase. The optimum temperature and pH of the enzyme activity were $55^{\circ}C$ and 6.5. The enzyme was stable after heat treatment at $80^{\circ}C$ for 30 min and stable in acidic and basic conditions (PH 6.0~11.0). The thermostable endo-chitinase from Thermoactinomyces vulgaris KFB-C100 was cloned into the plasmid pBR322 by using E. coli DH5$\alpha$ as a host strain. The positive clone carrying a recombinant plasmid (PKCHI23) with a 4.1-kb fragment containing the chitinase gene was found. The recombinant plasmid was analyzed to determine the essential region for chitinase activity and obtained a 2.3-kb fragment, which was sub cloned into pTrc99A using the PstI and SalI sites to construct pTrc99A/pKCHI23-3. The resulting plasmid exerted high chitinase activity upon transformation of E. coli XL1-Blue cells. Chitinase was overproduced 14 times more in the clone cells than in the wild-type cells and the enzyme was purified to homogeneity. The purified enzyme showed the similar properties as the native chitinase from T. vulgaris in terms of molecular weight and substrate specificity. The catalytic action of the cloned enzyme was an endo type, producing chitobiose as a major reaction product.

• Microbiology and Biotechnology Letters
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• v.8 no.2
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• pp.119-123
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• 1980

Culture conditions of yellow pigment in Monascus sp. were studied. According to the studies of culture conditions optimum condition was found to be pH 4.5, 3 days of incubation with 3% of sucrose as carbon source, 0.2 ％ of yeast extract as nitrogen source and 75m1 of medium in the 500m1 erlenmyer flask by rotary shaking (rpm 180) at 180 r.p.m. Effective levels of inorganic compounds were found to be 0.25 % of potassium phosphate monobasic and 0.1 ％ of Magnesium sulfate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.3
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• pp.279-285
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• 1992

Cytidine deaminase (EC 3.5.4.5) from Aspergillus fumigatus IFO 5840, which was the first cytidine deaminase to be found in a mold, was fractionated with ammonium sulfate (35-60%). When the enzyme solution in 0.25M of Tris-HCI buffer (pH 7.2) was preincubated at $37^{\circ}C$ for 25min, the enzyme activity was reached to maximum state. The optimum pH and temperature for the enzyme activity were found to be 6.8 to 7.2 and near $37^{\circ}C$, respectively. The enzyme was stable in a pH 7.2 to 9.0, and was generally stable at 4$0^{\circ}C$, but after treating at 6$0^{\circ}C$ for 20min at the optimal pH, 17% of the enzyme activity was inactivated, and disappeared completely by treating at 1$0^{\circ}C$ for 25min. Activation energy (Ea) of fungal cytidine deaminase was calculated as 14.190 Kcal /mol by the Arrhenius plot, and temperate coeffient ($Q_{10}$ ) of the enzyme was calculated as 2.163.

• Food Science and Preservation
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• v.13 no.2
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• pp.192-197
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• 2006

The optimum cultural conditions for production of yellow pigment by Monascus purpureus MMK2 were investigated in liquid culture. Monascus purpureus MMK2 was shown to give the maximum production of yellow pigment in the medium containing of 3.0% wheat flour, 0.15% $NaNO_3$, 0.25% $Na_2HPO_4\;12H_2O\;and\;0.15%\;MgSO_4\;7H_2O$. The optimal culture conditions for temperature and initial pH were $30^{\circ}C$ and 6.5, respectively. The yellow pigment production reached a maximum level at the 7th day of cultivation.

• Journal of the Korean Ceramic Society
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• v.23 no.3
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• pp.53-61
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• 1986

A gas sensor which has been made by wet process had fabricated by coating each of the mixture on alumina tube and firing at 85$0^{\circ}C$ for 3hrs. A gas concentration such $H_2$, CO, $C_3H_8$, $C_2H_2$ and $CH_4$ vs its detection voltage characteristics has been in-vestigated on $SnO_2-In_2O_3-MgO$ system doped with PdO, $La_2O_3$, $ThO_2$, NiO and $Nb_2O_5$ The optimum sensitivity composition for various gases were 90w/o $SnO_2$-9w/o $In_2O_3$-1w/o MgO for $H_2$, $C_2H_2$ CO and $C_3H_8$ and 95w/o $SnO_2$-4w/o $In_2O_3$-1w/o MgO for $CH_4$. The sample which has been made by wet process than dry process had predominated sensitivity for each gases and particle size of the sample coprecipitated with PH=9 was 0.1${\mu}{\textrm}{m}$ The $SnO_2$-In2_O_3-MgO$ system doped with 2w/o $Nb_2O_5$ and NiO was the most sensitive for $H_2$ and $C_2H_2$ gas. In $SnO_2$-In2_O_3-MgO$ system doped with $ThO_2$ the sensitivity of $H_2$ gas was decreased but CO gas was in-creased when dopant con was increased.

• Korean Journal of Food Science and Technology
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• v.18 no.4
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• pp.270-277
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• 1986

Ficin, a proteolytic enzyme in Fig latex, was extracted and purified with using ammonium sulfate and CM-cellulose column chromatography, respectively, and studied for its chemical properties. The disc gel electrophoresis showed one major and three minor bands for $(NH_4)_2SO_4$ extract and only one band showed after CM-cellulose chromatography. The optimum conditions for ficin activity was found to be pH 7.0 and $50^{\circ}C$. The amino acids composition of the purified ficin were 21.8% as acidic, 3.5% as basic and 74.7% as neutral amino acids. The amino acids analysis indicated that the ficin was composed of 174 amino acids residue having molecular weight of 19,500.