• KSBB Journal
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• v.5 no.4
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• pp.411-414
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• 1990

The extraction behavior of an alkaline protease using reversed micelles was investgated. The reversed micellar solution consisted of AOT in isooctane. It was found that distribution of arkaline protease into the organic phase increased at lower pH, lower ionic strength, and higher AOT concentration. When the real fermentation broth was extracted of alkaline protease, an activity yield of 20% and a purification factor of 2.0 were obtained.

• 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.

• Korean Journal of Microbiology
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• v.14 no.2
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• pp.49-49
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• 1976

Enzyme activities, such as glucoamylase dextrinogenic amylase, cellulase, acid protase and neutral protease, of Rhizopus isolated from various substrates collected throughout South Korea are measured, and their enzyme activities are surveyed from taxonomical, ecological and physiological viewpoint. Effect of carbon sources and phytohormones on the amylalse production of Rhizopus are also measured. Among the 735 strains of Phizopus isolated, strain number 587 exhibiting most prominent dextrinogenic amylase and netral protease activity is selected as the best strain, and the strain number 673, 108, 329, 165 and 728 are seleted for their predominant cellulase, acid protease, glucoamylase, dextrinogenic amylase and neutral protease activities, respectively. R.acidus and R.nigricans which exhibited relatively higher callulalse activity, showed lower activities for both amylase. R.tritici exhibited higher protease activity. The relations between activities and various substrates of wild strains are not outstnading difference, although the strains isolated from inland region exhibited more or less higher amylase and cellulase activities, than those of coast region, generally. Lactose and dextrin are most effective carbon sources for glucoamylase and dextrinogenic amylase production of the Rhizopus niveus, respectively. Although all phytohormones tested are effective for production of amylase by the Rhizopus strains, except nicotinamide for glucoamylase production, biotin and ascorbate are most effective for dextrinogenic amylase and glucoamylase production, respectively.

• Korean Journal of Microbiology
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• v.14 no.2
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• pp.47-56
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• 1976

Enzyme activities, such as glucoamylase dextrinogenic amylase, cellulase, acid protase and neutral protease, of Rhizopus isolated from various substrates collected throughout South Korea are measured, and their enzyme activities are surveyed from taxonomical, ecological and physiological viewpoint. Effect of carbon sources and phytohormones on the amylalse production of Rhizopus are also measured. Among the 735 strains of Phizopus isolated, strain number 587 exhibiting most prominent dextrinogenic amylase and netral protease activity is selected as the best strain, and the strain number 673, 108, 329, 165 and 728 are seleted for their predominant cellulase, acid protease, glucoamylase, dextrinogenic amylase and neutral protease activities, respectively. R.acidus and R.nigricans which exhibited relatively higher callulalse activity, showed lower activities for both amylase. R.tritici exhibited higher protease activity. The relations between activities and various substrates of wild strains are not outstnading difference, although the strains isolated from inland region exhibited more or less higher amylase and cellulase activities, than those of coast region, generally. Lactose and dextrin are most effective carbon sources for glucoamylase and dextrinogenic amylase production of the Rhizopus niveus, respectively. Although all phytohormones tested are effective for production of amylase by the Rhizopus strains, except nicotinamide for glucoamylase production, biotin and ascorbate are most effective for dextrinogenic amylase and glucoamylase production, respectively.

• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.524-530
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• 2006

Two protease inhibitors of 67 and 18 kDa, respectively, were purified from the eggs of glass fish, Liparis tanakai, by affinity chromatography and electro-elution method. The high molecular weight (HMW) protein was purified with a specific inhibitory activity, yield, and purity of 18.46 U/mg, 0.07%, and 131.86 fold, respectively, and was further characterized: Optimal temperature and pH for inhibitory activity of the HMW glassfish egg protease inhibitor were $40^{\circ}C$ and pH 6, respectively, and it was stable between $5^{\circ}C\;and\;50^{\circ}C$ in the pH range of 5-6 with maximal stability at pH 6. It was shown to be a competitive inhibitor against papain with an inhibition constant $(K_i)$ of 97.02 nM. Moreover, the 67 kDa protein inhibited cathepsin, a cysteine protease, more effectively than did an egg-white protease inhibitor. The HMW glassfish egg protease inhibitor was classified as a member of the family III (kininogen).

• Korean Journal of Food Science and Technology
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• v.21 no.6
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• pp.876-883
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• 1989

In order to investigate the index component and basis for the shelf-life of the grain share improved Meju, the effect of the storage time and package on the quality of Meju and soy sauce were studied during 90 days storage at $30^{\circ}C$. Also, sensory evaluation for the soy sauces from Meju with various storage time were carried out. During the storage period, moisture content, amylase and protease activity were decreased, on the other hand, the contents of amino-nitrogen and ammonia-nitrogen were increased. Among these components, protease activity was found the major index component for quality control because it was the most important component for soy sauce fermentation and the most changeable component of Meju during the storage period. According to the sensory test, the quality of soy sauce was agreed well with the protease activity of Meju, and the soy sauce from longer storage Meju was inferior organoleptic quality to that from shorter Meju. By the storage quality test, protease activity showed the highest value in 15 days storage Meju and decreased gradually with storage time passed. The basis of protease activity for quality control was 200 (O.D. at 660 nm/g). which was 50% of the initial activity And it was known that the shelf-life of the grain shape improved Meju was about 90 days . It was also shown that the storage in package did not affect noticeably to prolong the shelf-life of Meju on this study.

• Journal of Animal Science and Technology
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• v.51 no.6
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• pp.527-536
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• 2009

A potent protein degrading bacterium was isolated from soil samples of different environments. Polyphasic taxonomic studies and phylogenetic 16S rRNA sequence analyses led to identify the isolate IB No. 11 as a strain of Bacillus subtilis. The isolated strain was recognized to produce protease constitutively, and the maximum production (1.64 units/ml) was attained in a shake flask culture when the isolate was grown at $40^{\circ}C$, for 32 h in basal medium supplemented with starch (0.25%) and gelatin (1.25%) as sole carbon and nitrogen source, respectively. The optimum pH and temperature for the protease activity were determined to be pH 7.0 and $50^{\circ}C$, respectively. $Ca^{2+}$ and $Mn^{2+}$ enhanced remarkably the protease activity but neither showed positive effect on the protease's thermal stability. In addition, it was observed that the protease was fairly stable in the pH range of 6.5-8.0 and at temperatures below $50^{\circ}C$, and it could be a good candidate for an animal feed additive. The inhibition profile of the protease by various inhibitors indicated that the enzyme is a member of serine-proteases. A combination of UV irradiation and NTG mutagenesis allowed to develop a protease hyper-producing mutant strain coded as IB No. 11-4. This mutant strain produced approximately 3.23-fold higher protease activity (6.74 units/mg) than the parent strain IB No. 11 when grown at $40^{\circ}C$ for 32h in the production medium. The protease production profile of the selected mutants was also confirmed by the zymography analysis.

• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.2
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• pp.78-84
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• 2016

The antioxidant activity of silkworm powder treated by proteolytic enzyme was investigated. Total protein content of silkworm power was assayed using BCA, Bradford assays and SDS-polyacrylamide gel electrophoresis (PAGE) with alkaline protease treatment conditions including temperature and pH. The optimum condition of alkaline protease treatment for silkworm powder was found to be $60^{\circ}C$ and pH 7. The alkaline protease treatment resulted in increased contents of free amino acids, total polyphenol and total flavonoid compared to control group. The silkworm hydrolysates showed excellent antioxidant activities in various in vitro models such as 2,2 diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2,2 - azino-bis(3-ethylbenzthiazoline-6)-sulfonic acid (ABTS) radical scavenging activity. These results provide useful information for using silkworm powder as an ingredient in functional foods and for exploiting alkaline protease treatment to improve the extractability and bioactivity of a raw material.

• Microbiology and Biotechnology Letters
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• v.19 no.5
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• pp.450-455
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• 1991

A protease hyperproducer, ampicillin resistant mutant, Serratia sp. SMNT-1 was selected from Serratia marcescens ATCC 21074 by mutagenesis. The protease productivity of this strain was about 11 times as much as that of the parental strain. The enzyme showed maximal activity at pH 9.0 and $40^{\circ}C$ and was stable over the pH range from 6.0 to 10.0 at $4^{\circ}C$, whereas it was unstable at $37^{\circ}C$ in alkaline condition. the enzyme was inactivated by heating at $60^{\circ}C$ for 10 min. The enzyme was inactivated by EDTA and reactivated by $Zn^{2+}, Co^{2+},\; and \; Mn^{2+}$, but the proteoiytic activity of the enzyme was not affected by DFP. From the above results, the protease produced by Serratia sp. SMNT-1 was classified as a metalloprotese.

• Korean Journal of Microbiology
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• v.18 no.1
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• pp.15-19
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• 1980

In order to study on the pigment and protease of Serratia marcescens, the correlation between protease activity and pigment formation was investigated. The results are as follows ; (1) The protease activity exhibitied two pH optima 6.0 and 7.5, respectively. (2) The optimal temeprature of proteolytic activity was $45^{\circ}C$. With these-results, it is suggested that the proteolytic enzymes of Serratia masrecescens is stable at neutral pH range and more active at the high temeprature than lthat of otehr proteolytic enzymes.