• Food Science and Preservation
• /
• v.11 no.2
• /
• pp.227-232
• /
• 2004

• Korean Journal of Microbiology
• /
• v.28 no.2
• /
• pp.162-168
• /
• 1990

The aims of the present study were to evaluate the effects of culture conditions on the biosynthesis of extra-cellular alkaline protease in Streptomyces sp. The formation of aerial mycelia and spores were compared with the protease production in order to know the relations between the alkaline protease and the cell differentiation. As results, it was found that substrate concentration was very critical to regulate the formation of the protease, aerial mycelia, and spores, which were resulted from the changes of culture pH to acid. When the culture pH was adjusted with phosphate buffer from pH 6 to pH 9, the alkaline protease production was increased as the culture pH increased whereas aerial mycelia and spore formation were reversely related to the culture pH. Therefore, it was thought that the culture pH was an important factor to regulate the alkaline protease synthesis.

• Korean Journal of Food Science and Technology
• /
• v.21 no.3
• /
• pp.379-386
• /
• 1989

The soy milk prepared from soy protein concentrate was treated with microbial protease or papain. Growth and acid production by Lactobacillus acidophilus in soy milk containing partially hydrolyzed proteins were investigated. Sensory evaluation of yogurt beverage prepared from protease treated soy milk was also performed. Protease treatment of soy milk enhanced acid production by lactic acid bacteria, particularly in case of microbial pretense and simultaneous treatment by two types of protease showed synergistic effect. pH and number of viable cells were not affected markedly by pretense treatment. Microbial pretense treatment up to 15 minutes or papain treatment up to 45 minutes enhanced acid production, but further treatment up to three hours did not affect the acidity markedly. rho sensory evaluation showed that overall acceptability and taste of soy yogurt beverage were slightly improved when soy milk was treated with microbial pretense of 0.2% or papain of 0.2%. The amount of non-protein nitrogen considerably increased by pretense treatment of 15 minutes and it increased gradually by further treatment up to three hours.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.11
• /
• pp.1612-1617
• /
• 2009

Aspergillus sp. 101 was isolated from the Korean traditional soybean paste for the production of a salt-tolerant protease. The optimal condition for the production of a salt-tolerant protease was determined with various energy sources such as carbon, nitrogen, and protein, and at different culture conditions such as temperature, pH, incubation time and NaCl concentration. The most favorable organic nitrogen sources were 2% defatted soybean flour (DSF) and soy protein isolate (SPI). Optimal pH and temperature were pH 6.0 and $25{\sim}27^{\circ}C$, respectively. Therefore, Aspergillus sp. 101 protease was a mild acid (or neutral) protease. Protease production was the highest at 0.1% concentration of $CaCO_3,\;K_2HPO_4$ and Arabicgum. Aspergillus sp. 101 could grow in culture medium at 15% NaCl concentration and produce a salt-tolerant protease even at 7% NaCl. The cell mass and protease activity of Aspergillus sp. 101 cultured in a modified medium was comparatively higher in Czapek dox and protease producing media. Hence, Aspergillus sp. 101 protease can be utilized in soy or fish sauce industry as a salt-tolerant protease starter.

• YAKHAK HOEJI
• /
• v.2 no.1_2
• /
• pp.41-47
• /
• 1953

"Kimchi" is a most popular pickled Vegetables in Korea. In this paper, eight strains of gram positive rocls and two strains of gram positive cocci are isolated from "Kimchi". For the each isolated strains, the acid production test against carbohydrate and production test of amylase, protease, esterase, and general biological tests are investigated. The most active one for the amylase production is No.2 strain the most active one for the Protease production is No.5,6, and 9 strains. And that for Esterase production is No.9 strain (see the original paper on the results in this journal page)

• Proceedings of the PSK Conference
• /
• 2002.10a
• /
• pp.331.1-331.1
• /
• 2002

Actinomycetes CS0703 has been isolated in soil sample from location in the Jeju province. Korea. and produces alkaline extracellular proteases. To maximize protease production, initial pH of the culture medium was adjusted to 12.0 with NaOH and incubated at $48^{\circ}C$ on a rotary shaking incubator(180rpm). Actinomycetes CS0703 produced high level of protease at late exponential phase when grown in OSYM medium (oatmeal 2.0%. soybean meal 1%. dried yeast 1%. mannitol 1%). (omitted)

• Korean Journal of Microbiology
• /
• v.48 no.4
• /
• pp.298-304
• /
• 2012

Among 63 Bacillus strains grown at $60^{\circ}C$ from sixteen samples of homemade Korean soybean paste, one strain was selected for producing the thermostable protease. The isolate has been identified as Bacillus licheniformis on the basis of its 16S rDNA sequence, morphology and biochemical properties. Culture filtrate of the isolate showed maximal protease activity at the reaction condition of $60-65^{\circ}C$ and pH 11. The culture filtrate retained more than 87% of initial protease activity after incubation for 30 min at $60^{\circ}C$ without substrate. In order to develop the medium composition, effects of ingredients including nitrogen sources, carbon sources, metal ions and phosphate were examined for protease production of the isolate. Lactose and soytone peptone were the most effective carbon and nitrogen source for the enzyme production. After the late logarithmic growth phase the isolate began to produce the protease, and the maximum protease productivity was reached to 550 unit/ml in the optimized medium consisting of lactose (3%), soytone peptone (1.5%), $MgSO_4$ (0.1%), $K_2HPO_4$ (0.03%), and $KH_2PO_4$ (0.03%) at 28 h of incubation.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.9
• /
• pp.1230-1236
• /
• 2012

Fish meal grades SL1 and SL2 from Sardine (Sardinella longiceps) and NJ from Pink Perch (Nemipterus japonicas) were evaluated as a sole source of carbon and nitrogen in the medium for alkaline protease production by Bacillus pumilus MTCC 7514. The analysis of the fish meal suggests that the carbon and nitrogen contents in fish meal are sufficient to justify its choice as replacement for other nutrients. Protease production increased significantly (4,914 U/ml) in medium containing only fish meal, compared with the basal medium (2,646 U/ml). However, the elimination of inorganic salts from media reduced the protease productivity. In addition, all the three grades of fish meal yielded almost the same amounts of protease when employed as the sole source of carbon and nitrogen. Nevertheless, the best results were observed in fish meal SL1 medium. Furthermore, protease production was enhanced to 6,966 U/ml and 7,047 U/ml on scaling up from flask (4,914 U/ml) to 3.7 and 20 L fermenters, respectively, using fish meal (10 g/l). Similarly, the corresponding improvement in productivities over flask (102.38 U/ml/h) was 193.5 and 195.75 U/ml/h in 3.7 and 20 L fermenters, respectively. The crude protease was found to have dehairing ability in leather processing, which is bound to have great environmental benefits.

• Korean Journal of Clinical Laboratory Science
• /
• v.44 no.4
• /
• pp.216-221
• /
• 2012

The fruiting body of Cordyceps is derived from the pupa or larva of insects infected by the entomopathogenic fungi Cordyceps. The fruiting body has been used as an anti-cancer and anti-inflammatory ingredient in traditional Chinese medicine. The biochemical characteristics of protease isolated from Cordyceps nutans were investigated in this study. The culturing period for production of protease by C. nutans was 10days. The acidity was pH 7.0, and the temperature was $25^{\circ}C$. The carbon and nitrogen sources for the production of the protease were glucose and yeast extract, respectively. The ratio of C/N was 2% glucose and 0.6% yeast extract. 0.06% $CuSO_4$ was used as the inorganic salt. The investigation into the acidity of the protease produced by C. nutans revealed that the optimal pH and temperature were pH 7.0 and $30^{\circ}C$. The stability of the protease was shown as pH 6.0~9.0 and $30{\sim}50^{\circ}C$. The investigation into the influence of the metal ions on the enzyme activation of C. nutans revealed that it was inhibited in $ZnSO_4$ and activated in $FeSO_4$.

• Microbiology and Biotechnology Letters
• /
• v.22 no.1
• /
• pp.59-64
• /
• 1994

The production and the characteristics of protease produced by Bacillus sp. SH-8 and Bacillus sp. SH-8M were investigated under the different pH conditions. Bacillus sp. SH-8 and Bacillus sp. SH-8M showed the maximum activity of protease at 60 hours(70 units/ml) AND 96 houre(50 units/ml) cultivation, respectively, under the alkaline condition(pH 10.2). However, Bacillus sp. SH-8M exhibited the maximum activities in 8 days cultivation at pH 6.9 and in 6 days cultivation at pH 7.7 Bacillus sp. SH-8M showed the protease activity at the pH change from alkaline to neutral condition, whereas Bacillus sp. SH-8 did not. In addition. all the enzymatic characteristics of protease produced by Bacillus sp. SH-8 and Bacillus sp. SH-8M were similar with the regardless of different pH conditions.