• Journal of Microbiology and Biotechnology
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• v.1 no.4
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• pp.288-292
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• 1991

The aim of the current study is to evaluate the effects of medium compositions on the production of protease inhibitor in Streptomyces sp. SMF13. The production of protease inhibitor was counter-currently linked to extra-cellular protease, which were regulated by the culture conditions. Nitrogen source was the most critical ingredient affecting the production of protease inhibitor and protease. Carbon source was an important factor to determine the culture pH which affected very clearly the formation of protease and protease inhibitor. Inorganic phosphate inhibited the protease inhibitor production which was linked to the cell growth rate, although the optimal conditions for the production of protease inhibitor were not favouring to the cell growth.

• Microbiology and Biotechnology Letters
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• v.8 no.2
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• pp.77-85
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• 1980

This experiment was conducted to investigate the conditions for production and the characteristics of pretenses. Aspergillus oryzae KC-15, which is selected as a superior strain for the production of the protease, was used in this study. The results obtained were as follows: 1. The optimum culture time for the production of acid, neutral and alkaline protease on wheat bran medium were about 48, 48 and 72hr, respectively. The protease-produced by the strain were mainly alkaline and neutral one, but the production of acid protease was feeble extremely. 2. The addition of NaH$_2$PO$_4$, Na$_2$HPO$_4$, glucose, rice powder and Na-glutamate respectively to wheat bran media were effective for the production of alkaline and neutral protease, and the addition of (NH$_4$)$_2$HPO$_4$, glucose and rice powder respectively were effective for the production of acid protease. 3. Characteristics of professes(equation omitted) 4. As a heat resistance agent, NaH$_2$PO$_4$was the most effective one. The optimum amount of NaH$_2$PO$_4$was 10mg for alkaline and neutral protease, and 5mg for acid protease. 5. The heat resistance of the Protease by NaH$_2$PO$_4$was not recognized mostly above 6$0^{\circ}C$. 6. After the treatment of enzyme solution with 10mg of NaH$_2$PO$_4$for 30 minutes at 55$^{\circ}C$, the residual activities measured for alkaline, neutral and acid protease were 58, 57 and 55％ respectively.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.207-211
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• 1997

Media optimization for the production of thermostable protease specifically hydrolyzing defatted soybean meal (DSM) from Bacillus licheniformis NS70 was performed by two methods, one-at-a-time method and response surface methodology (RSM). The best carbon source and nitrogen source for the protease production were lactose and DSM, respectively. The maximum protease production estimated by RSM was 606 U/L at 1.11% lactose and 0.43% DSM, the value of which was nearly consistent to the experimental value of 599 U/L. Yeast extract suppressed the protease production. The medium pH was slightly increased at the beginning stage of fermentation, and it tended to decrease after 8 hours. The optimal pH for the protease production was 7.2 in the batch fermentation.

• The Korean Journal of Food And Nutrition
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• v.13 no.2
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• pp.171-175
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• 2000

Microbial proteases have certain unique characteristics, and are now widely used in food, leather, detergent, and pharmaceutical industries. Thermophilic Actinomyces producing the protease was isolated from soil in Wonju city. This strain was able to grow and produce protease at the culture temperature of 50$^{\circ}C$. The maximum protease production was obtained when 0.5% soluble starch and 0.4% yeast extract were used as carbon and nitrogen source, respectively. The other culture condition for the maximal productivity of the protease was 0.1% K2HPO4, and 0.05% CaCl2 at initial pH 8.0 for 48 hours.

• Korean Journal of Microbiology
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• v.18 no.2
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• pp.51-58
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• 1980

Mutational experiments were performed to improved to improve the protease productivity of Aspergillus flavus KU 153, which is selected among the wild strains. A UV-induced mutant strain having high protease productivity was obtained by the use of the clear zone method as a simple criterion for a primary screening test. Neutral and alkaline protease activities of hte mutant strain were higher than 1.8 times, comopared with those of the parental strain, respectively, while in the case of acid protease, it was 2.7 times. The mutant strain selected was more powerful in the production of cellulase and amylase, as well s protease in wheat bran, compared with those of the parental strain. protease production of the parental strain has reached maximum level at 3 days culture, while alkaline nad neutral protease production of the mutantstrain has reached at 2 days culture. On the other hand, the mutant strain formed the spore slowly, compared with the parental strain. Column chromatography of the neutral protease on DEAE-Sephadex A-50 showed that the mutant strain was not induced the formation of another neutral protease isozyme, but induced the variation in the function of regulatory gene.

• Journal of Life Science
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• v.31 no.8
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• pp.761-770
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• 2021

In this study, the optimal medium composition for enhancing protease production was established by the Bacillus strain isolated from Makgeolli, a traditional fermented food, using the response surface methodology. B. amyloliquefaciens SRCM115785 was selected as the protease producer by productivity analysis and identified by 16S rRNA gene sequencing. Plackett-Burman design (PBD) was introduced to analyze the effect of each component on protease production among the 11 selected medium components. As a result, glucose, yeast extract, and beef extract were finally selected as factors for enhancing protease production. Central composite design (CCD) analysis was designed as a method to determine the optimal concentration of each component for protease production and the concentration of each medium composition for maximum protease production was predicted to glucose 6.75 g/l, yeast extract 12.42 g/l and beef extract 17.48 g/l. The suitability of the experimental model was proved using ANOVA analysis and as a result of quantitative analysis to prove this, the amount of increase was 230.47% compared to the LB medium used as a control. Through this study, the optimization of medium composition for enhancing protease production was established, and based on this, it is expected that it can be efficient use of protease as an industrial enzyme.

• Journal of the Korean Wood Science and Technology
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• v.32 no.5
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• pp.12-19
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• 2004

This study was performed to investigate the optimum condition of protease production from submerged culture of oak mushroom (Lentinula edodes, Sanlim No. 5) and its enzymatic features. Among several combinations of media, the combination of wheat bran, corn flour, water and corn oil (WB+CF+W+ CO) yielded 84.8 U/g of maximum protease activity. This combination of ingredients, in spite of not being particularly protein-rich in comparison to the other media, allowed for good growth of the fungus and maximal protease production. Comparison of different growth medium liquids indicated that demineralized water afforded the best growth of the fungus and the highest protease activity. Acetate buffer and acidified water negatively affected The protease production peaked around 72 hr of incubation, and decreased thereafter. The molecular weights of produced protease were about 45,000 by Sephadex G-75 chromatography. The pH optimum for protease activity was 4, while maximal activity incubated at 37℃ for 1 hr was observed between pH 4~6. The optimum temperature of this protease was 55℃, and the enzyme was active over a broad temperature range (30~60℃), indicating that this protease would be suitable for a wide range of applications where. different pH and temperature are necessary, such as digestive aids, food industry, beer and tannery industries.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.5
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• pp.1010-1016
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• 1999

Protease related mold was isolated and selected as a starter culture for commercial production of meju. Isolated microorganism was identified as Syncephalastrum racemosum PDA 132 2. To obtain basic data about protease for production of soybean peptides and application of the strain in meju fermentation, we extrated and purified protease and charateristics of the enzyme were investigated. The optimum condition for the production of enzyme was pH 4.0, 30oC, 5 days. The protease was purified 19.7 folds by gel filtration and ion exchange chromatography and specific activity was 12.4unit/mg. The purified enzyme was 34kDa in size, thiol protease(100% inhibited by PCMB), and was acidic protease(stable between pH 2.0~5.0). Vmax of the enzyme was 2.14 g/min which was lower(1/50) than that of by Asp. wentti and B. subtilis.

• KSBB Journal
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• v.4 no.2
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• pp.128-133
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• 1989

Carbon sources and nitrogen sources are known to be very important in protease production by microorganisms. The effects of carbon source and nitrogen source on protease biosynthesis by Bacillus licheniformis were investigated using batch cultures. As initial carbon and nitrogen concentrations of culture medium increased, the specific growth rate of Bacillus licheniformis was increased, while the specific protease production rate was decreased. From the results of batch cultures, a mathematical model which considers the effects of carbon source and cnitrogen source was proposed and the methods to increase the productivity of protease were discussed.

• Microbiology and Biotechnology Letters
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• v.29 no.3
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• pp.134-141
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• 2001

A bacterial strain KP-364 producing extracellular keratinolytic protease was isolated from the soil of the poultry fac-tory. It was identified as Pseudomonas sp. based on its morphological and physiological characteristics, The optimal culture conditions for the production of keratinolytic protease by Pseudomonas sp. KP-364 were investigated. The composition of optimal medium for the keratinolytic protease was 2.0% glucose, 0.5% soybean meal. 0.5% $NaNO_3$ and 0.2% KCI Optimal initial pH for production of Keratinolytic protease production were 6.5 and $37^{\circ}C$ respec- tively. The keratinolytic protease production reached a maximum of 1,270 U/ml/hr after 48 hours cultivation under the optimal culture conditions.