• Microbiology and Biotechnology Letters
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• v.48 no.3
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• pp.358-365
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• 2020

An organic solvent- and bleach-stable protease-producing strain was isolated from a polluted river water sample and identified as Aeromonas veronii OB3 on the basis of biochemical properties (API 20E) and 16S rRNA sequence analysis. The strain was found to hyper-produce alkaline protease when cultivated on fish waste powder-based medium (HVSP, 4080 U/ml). The biochemical properties and compatibility of OB3 with several detergents and additives were studied. Maximum activity was observed at pH 9.0 and 60℃. The crude protease displayed outstanding stability to the investigated surfactants and oxidants, such as Tween 80, Triton X-100, and H₂O₂, and almost 36% residual activity when incubated with 1% SDS. Remarkably, the enzyme demonstrated considerable compatibility with commercial detergents, retaining more than 100% of its activity with Ariel and Tide (1 h, 40℃). Moreover, washing performance of Tide significantly improved by the supplementation of small amounts of OB3 crude protease. These properties suggest the potential use of this alkaline protease as a bio-additive in the detergent industry and other biotechnological processes such as peptide synthesis.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.519-526
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• 2008

To improve the quality of traditional kochujang, strains with high protease and amylase activity were isolated and identified from Sunchang traditional kochujang. Twenty-three strains strongly producing protease and 16 strains strongly producing $\alpha$- and $\beta$-amylase were isolated by using 1% isolated soy protein agar medium and 2% starch agar medium, respectively. Protease activities of the IA7, I5, and IA2 strain were 22.5, 21.2, and 20.6 unit/mL, respectively, and were higher than those of the other strains. Stains with high $\alpha$-amylase activity included K9 (967.8 unit/mL), K14 (828.3 unit/mL), K13 (662.5 unit/mL), K8 (601.5 unit/mL), and K11 (405.9 unit/mL). The $\beta$-amylase activity of the K11 strain was the highest, 34.3 unit/mL, among the isolated strains. Based on morphological, physiological properties, and API 50CHB-kit test for assimilation of 49 carbohydrates, 8 strains selected according to protease, $\alpha$-amylase, and $\beta$-amylase activities were tentatively identified as Bacillus megaterium (IA2), Bacillus subtilis (IA7, 15), Bacillus amyloliquefaciens (K8, K9, K11, and K13), and Bacillus stearothermophillus (K14). The IA7, 15, and K11 strains were finally identified as B. subtilis (99% ID) based on 16S rDNA sequencing.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.461-467
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• 2009

A bacterial strain was screened and identified from sea sediments in Tongyeong coastal area in order to obtain proteases or peptidase cleaving C-terminal of glutamic acid. Strain TS0611, which showed the highest activity from 5 isolated protease producing strains, was selected and its properties investigated. Strain TS0611 was a gram-positive rod, $1.2\;{\mu}m$ in cell length, catalase positive, motility-positive, melanin-negative and grew at 15~$50^{\circ}C$, and hydrolyzed gelatin and casein. This strain was identified as Bacillus thuringiensis or Bacillus cereus based on results from the API system(API 50 CHB) which examined saccharides properties, fatty acid composition of cell wall, and 16S rRNA gene sequence.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.430-434
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• 2004

Three extracellular protease-deficient Bacillus subtilis strains were transformed with the plasmid pCK98 containing the endo-$\beta$-1,4-glucanase (Eng) gene of B. subtilis BSE616. The three transformants, B. subtilis DB104 (pCK98), WB600 (pCK98) and WB700 (pCK98), produced the same high level of enzyme activity and showed similar patterns of cell growth and enzyme production. When B. subtilis DB 104 (pCK98), a two-extracellular protease deficient strain, was cultured for 22 h, almost all the secreted enzyme was found to be in the completely cleaved form by both activity staining and Western blotting studies. B. subtilis WB600 (pCK98), a six-extracellular protease-deficient strain, produced a partially cleaved form in addition to the intact form of the enzyme, although the degree of internal cleavage of the enzyme was greatly reduced. With B. subtilis WB700 (pCK98), a seven-extracellular protease-deficient strain, almost all the enzyme was produced as the intact uncleaved form. This study illustrates that a role of the V pr protease is to degrade foreign proteins produced in B. subtilis and WB700 is a suitable expression system for producing the intact form of the Eng and other foreign proteins that may lose at least part of their efficacy due to internal proteolytic cleavage.

• 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.

• Applied Biological Chemistry
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• v.32 no.2
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• pp.148-153
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• 1989

Several mutants for rapid fermentation of Korean soybean paste which will improve the productivity of amylase and protease was obtained through the second mutation of the original strain using UV radiation. The original strain was the NTG treated mutant of the Bacillus sp. producing peculiar flavour which had been isolated from the Korean soybean paste. A mutant (SSA3-2M1) could improve the productivity of amylase by 4.4 times and that of protease by 3.7 times. Other one (SSA3-2M2) depressed deaminase productivity by 90% in spite of improvement of amylase and protease. The enzymes produced by strains were similar in enzymatic properties such as optimal reaction pH and temperature. The reaction and productivity of enzymes were not influenced in the high concentration of salt.

• KSBB Journal
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• v.16 no.2
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• pp.158-162
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• 2001

A halotolerant and extracellular protease-producing yeast was isolated from traditional Meju and identified as a strain of Hansenular polymorpha by investigating its microbiological characteristics. The optimum pH, temperature and NaCl concentration reauired for the growth of Hansenular polymorpha S-9 were found to be pH 6.0, 30$^{\circ}C$ and 0.5 M, respectively. Extracellular protease was produced maximally at 10 U ml(sup)-1 when Hansenular polymorpha S-9 was grown on the medium containing 1.0% beef extract and 0.1 M NaCl for 12 hr at 30$^{\circ}C$. About 13% of the angiotensin-converting enzyme (ACE) inhibitory activity was shown in the hydrolysates which were obtained from the digestion of soybean protein (6 mg) for 6 hr at 30$^{\circ}C$ by the crude enzyme (1 U).

• KSBB Journal
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• v.19 no.4
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• pp.295-300
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• 2004

A marine bacterium for producing an collagenolytic protease was isolated from the southern sea of Korea and identified as Vibrio vulnificus and named as Vibrio vulnificus CYK279H. This strain producing an collagenolytic protease was showed high activity toward collagen and gelatin as substrate. The optimum initial pH, NaCl, and temperature for cell growth and protease production was 7.5, 2.0% and 25$^{\circ}C$, respectively. Optimization for collagenolytic protease production was composed of 0.3% D-galactose, 0.6% yeast extract, 4.0% gelatin, 0.2% (NH$_4$)$_2$SO$_4$, and 0.2 mM ferric citrate in artificial sea water. The maximum protease production was required gelatin and yeast extract. The collagenolytic protease production by Vibrio vulnificus CYK279H reached a maximum of 73 unit/l after the cultivation for 18 h under the optimized medium.

• Applied Biological Chemistry
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• v.31 no.4
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• pp.346-350
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• 1988

A mutant for Korean soy sauce which wilt improve the productivity of amylase and protease was obtained through the second mutation of the original strain using UV radiation. The original strain was the NTG treated mutant of the Bacillus sp. producing peculiar flavour which had been isolated from the korean soy sauce. The mutant could improve the productivity of amylase by 58% and that of protease by 41%. The enzyme produced in this way were similar in enzymatic properties such as optimal reaction pH and temperature. The reaction was not deterred by highly densed salt solution of 5 M and the enzyme productivity was not influenced in the concentration of up to 2 M.

• Fashion & Textile Research Journal
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• v.8 no.2
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• pp.239-244
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• 2006

For studies of fibrinolytic enzyme strain K-54 was isolated from the Korean traditional food chungkook-jang. Isolated strains K-54 was identified as Bacillus subtilis. The molecular weight of fibrinolytic enzyme from B. subtilis K-54 was 27 kDa. Optimum temperature for fibrinolytic enzyme of B. subtilis K-54 was $50-70^{\circ}C$ and optimum pH for producing the enzyme of this strain was ranging from 8 to 12. Also, it was found out enzyme activity was completely inhibited by 1mM PMSF. The result indicated this enzyme was thermo-stable alkaline serine protease with strong fibrinolytic activity. The wool and silk were treated with protease of B. subtilis K-54. As a result, the property of dyeing of wool fabrics was increased. By the increasing of treatment time became smoothened. But the change of mechanical properties were not changed.