• Korean Journal of Microbiology
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• v.51 no.1
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• pp.75-80
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• 2015

Pseudoalteromonas donghaensis HJ51, isolated from the East Sea, has been reported as a novel strain to produce extracellular protease. Crude supernatant was used to determine optimal activity and optimal production conditions for the enzyme. It was found that the optimal temperature and pH of the protease were $40^{\circ}C$ and pH 7.5-10.5, respectively. The enzyme activity was kept to 88% at the pH 11. In metal requirement analysis, the enzyme exhibited the highest activity when 10 mM $Fe^{3+}$ was supplied. While supplementation of additional carbon sources used in study showed no positive effect on cell growth and enzyme activity, the addition of beef extract, tryptone, or casamino acids instead of peptone of PY-ASW containing 1% glucose increased enzyme production to 21, 7, 4%, respectively. Taken together these properties, the enzyme produced from P. donghaensis HJ51 can be applied to the industries that require protease activity under alkaline pH and low temperature.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.92-99
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• 1989

The soy milk prepared from soy protein concentrate was treated with pretense of various concentrations. Growth and acid production by Lactobacillus acidophilus or L. bulgaricus in soy milk containing partially hydrolyzed protein were investigated. Sensory evaluation of soy yogurt beverages prepared from pretense treated soy milk was also performed. The treatment of soy milk with pretense markedly enhanced acid production by lactic acid bacteria, particularly by L. acidophilus, whereas pH and number of viable cells were not .affected by pretense treatment. Protease treatment of 15 minutes greatly enhanced acid production by lactic acid bacteria, but further treatment up to three hours did not affect the acidity markedly. The sensory evaluation showed that overall acceptability of soy yogurt beverages was slightly improved when soy milk was treated with pretense of 0.1%. The amount of non-protein nitrogen was considerably increased by pretense treatment of 15 minutes and it reached the maximum value by treatment of two hours.

• Applied Biological Chemistry
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• v.41 no.3
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• pp.213-218
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• 1998

A bacterium with potent activity of pigment production and protease was isolated and identified as being Bacillus sp. CS-17. Cell growth, protease activity and pigment production of the strain reached to its maximum point after 24 hrs, 48 hrs, 72 hrs, respectively. The best pigment producing ability of Bacillus sp. CS-17 was shown on basal medium for pigment production added 1.0% soybean. The high effcient conditions for pigment production was obtained at culture of pH 8.5, $37^{\circ}C$ and 72 hours. Among the tested 5 gram positive strains and 6 gram negative strains, weak antibacterial activity of pigment concentrated extracts was appeared against growth of B. subtilis, P. aeruginosa, S. typhimurium, E. aerogenes, B. cereus, A. hydrophila.

• Applied Biological Chemistry
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• v.34 no.4
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• pp.307-311
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• 1991

A moderate halophile, ES 10 which produces a high level of alkaline protease was isolated from the salted anchovies and indentified as a strain of Halomonas sp. The optimum growth of the Halomonas sp. was revealed in the presence of 2 M NaCl and its growth rate in the Temporary Synthetic Medium was increased by adding DL-alanine, but inhibited by adding L-proline. The concentration of $Na^+$, $K^+$ and $Mg^{2+}$ in the cell mass of the Halomonas sp. ES 10 was 5-, 25- and 35-fold higher by dry weight basis, respectively than those of B. subtilis or E. coli. Norberg and Hofsten medium with 1 M NaCl was selected as the best medium for producing high level of alkaline protease. The optimum temperature for the growth and protease production was equally $20^{\circ}C$.

• Korean Journal of Agricultural Science
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• v.13 no.2
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• pp.279-288
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• 1986

One hundred and fifty one mutant strains were obtained from the parent strain Aspergillus oryzae MF by ultra-violet ray irradiation. Among those mutants a strain, Asp. oryzae UM-36 which hyperprodued protease, was selected and its morphological characteristics and the production of enzymes protease, ${\alpha}$-amylase, and glucoamylase on wheat bran koji and on soy-sauce koji were studied. The results obtained were as follows 1. The selected mutant showed slower growth and weak sporulation on malt agar and on Czapek agar than the parent strain. 2. The conidiophores of the mutant were generally shorter than those of the parent when grown on malt agar. 3. Sectoring in colonies was not found when grown on malt agar and on Czapek agar. 4. The level of protease production by the mutant was increased approximately 1,4-fold higher on wheat bran koji and 2-fold higher on soysauce koji than by the parent. 5. The production of ${\alpha}$-amylase and glucoamylase by the mutant were also increased as compared with the parent on wheat bran koji and on soy sauce koji. 6. In the case of parent strain and mutant strain, the highest activity of protease appeared after three days in wheat bran medium at $30^{\circ}C$ incubation, but the highest activities of ${\alpha}$-amylase and glucoamylase appeared after two days.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.373-378
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• 2008

The objective of this paper was to investigate optimal culture conditions for the production of an inhibitor against subtilisin-like protease from Streptomyces thermocarboxydus (S. thermocarboxydus) C12 isolated from sediments of Gwangyang coast. The optimal temperature and initial pH for the production of subtilisin-like protease inhibitor were $40^{\circ}C$ and pH 8.0, respectively. Inhibition activities were high for galactose, glucose and fructose. The best carbon source and its concentration were galactose and 1.6% (w/v), respectively. Inhibition activities were also high in medium containing polypeptone, proteose and peptone. Optimal nitrogen source and concentration were protease peptone and 0.5% (w/v), respectively. Optimal concentrations for inhibitor production were 1% (w/v) for NaCl and 1 mM LiCl for metal salts. The subtilisin-like protease inhibitor from S. thermocarboxydus C12 showed a maximum inhibitor activity after cultivation for 84 h under the optimized medium.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.2
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• pp.142-146
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• 2003

Three insect cell lines, Sf9, Sf21 and Tn5Bl-4, and four different kinds of serum free media (SFM), Sf 900 II, EX-CELL 420, EX-CELL 405 and Express Five, were used to compare the nutrient consumption, byproduct formation, production of recombinant protein and protease activity in suspension cultures. The Sf 900 II SFM was a ppropriate for the cell growth and protein production of the Sf9 and Sf21 cell lines. When the Tn5Bl-4 cell line was grown in the Express Five SFM, the specific growth rate was 1.6 fold higher than those of either the Sf9 or Sf21 cell lines. The glucose and glutamine consumption rates per cells, were 4 and 2.3 times higher than those of the Sf9 cell line, respectively. The overall yield coefficients of the lactate and ammoniumion were 2.8 and 1.5 times higher compared to those of the Sf9 cell line. respectively. The maximum specific ${\beta}$-galactosidase production rate was 4.5 fold that of the Sf9 cell line, a 3 times higher protease activity per cell.

• Food Science and Preservation
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• v.12 no.5
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• pp.460-464
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• 2005

In order to produce functional soy hydrolysates, we investigated the characteristics of soy hydrolysates prepared with 4 kinds of commercial proteases. The yield was high in protease(B), in which 43.2% soy flour and 61.6% SPI were obtained. The solubility and the contents of total phenolic compound were greatly increased by the treatment of protease(B) along with protease(C). The calcium intolerance was improved after the protease(B) treatment in soy flour or Soybean Protein isolate (SPI). Consideration for the physicochemical characteristics including yield, protease(B) has potential application for the production of soy hydrolysates. After the protease treatment, the beany flavor of soy flour became weak and the bitter taste was strong in both soy flour and SPI. However, there was no difference of beany flavor and bitter taste among delete protease hydrolysates. Nevertheless, further modifications and improvements to the sensory characteristics would be required for the development of a range of products with the hydrolysate.

• Korean Journal of Microbiology
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• v.30 no.6
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• pp.501-506
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• 1992

An alkalophilic Vibrio sp. RH530 showing high proteolytic activity was isolated form soil samples by enrichment culture. The activity staining using gelatin SDS- polyacrylamide gel electrophoresis (PAGE ) revealed that the strain produced an alkaline major protease (Apr B) with a size of 27 kDa, and at least six minor proteases. The apparent sizes of four of the minor proteases were approximately 45, 28, 22 and 19 kDa. Apr B and five of the minor proteases were inhibited by serine protease inhibitors including PMSF and DFP, suggesting that they are serine proteases. One of the minor proteases was inhibited by metalloprotease inhibitors, not by serine protease inhibitors, indicating it to be a metalloprotease. Furthermore, the activities of Apr B and Prt 3 were not inhibited by SDS in the reaction mixture. The production of Apr B and some of the minor proteases was specifically affected by culture temperature (30 to 37.deg.C) and pH (7 to 10). The production of Apr B. Prt 2, Prt 5 and Prt 6 was mainly affected by culture temperature, while Prt 4 by culture pH. Prt 1 and Prt 3 were not affected by neither of these factors.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.3
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• pp.279-286
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• 1989

The alkaline protease producing mold isolated from and identified as Aspergillus fumigatus. It was found that the production of alkaline protease reach to maximum was cultured for 3 days at $30^{\circ}C$. The enzyme was purified 86.13 fold and yield of the enzyme purification was 6.4%, The purification procedure include ammonium sulfate treatment, gelfiltration on Sephadex G-25, G-75, G-150 and DEAE-cellulose ion-exchange chromatography. When the purified enzyme was applied sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the molecular weight was estimated about 63000. This enzyme composed 17 amino acids and main amino acids of this enzyme were glycine and glutamic acid.