• 생명과학회지
• /
• 제9권4호
• /
• pp.348-357
• /
• 1999

Seventy-two strains of Pseudomonas aeruginosa isolated from the patients were tested for pigment production, exoenzyme production and antimicrobial susceptibility. In the pigment production test, 23.6% of total 72 strains produced both pyocyanine and pyoverdin. Pyoverdin and pyomelanin producing strains were in 9.7%, and 5.5% produced pyoverdin and pyorubin. Strains producing of all of exoenzyme, protease, elastase and lecithinase were in 5.6%. The most common type of exoenzyme production was both protease and elastase producing. Protease producing strain were 23.6%, Among the 72 strains, 50% produced protease. As the result of antimicrobial susceptibility in the isolated 20 strain, most strain were resistant to sulfamethoxazole(90%), but sensitive to other tested antibiotics more than 60%. The MIC50 and MIC90 level of tested antibiotics to 70 strains were 128 $\mu\textrm{g}$/$m\ell$, 512 $\mu\textrm{g}$/$m\ell$ for KM, 8,256 $\mu\textrm{g}$/$m\ell$ for GM, 8, 128 $\mu\textrm{g}$/$m\ell$ for CPZ, and 8, 64 $\mu\textrm{g}$/$m\ell$ for PIPC respectively.

• 한국축산식품학회지
• /
• 제30권5호
• /
• pp.804-810
• /
• 2010

This study was performed to select protease-producing Bacillus sp. as a potential probiotic starter for fermented meat products. In order to isolate protease-producing bacterium from meju, measured the diameter of the clear zone on agar plate (TSA, 1% (w/v) skim milk) and analyzed for intracellular protease activity, then 10 Bacillus-like strains were isolated. Three Bacillus-like strains (P19, P27, and P33) among 10 strains were able to tolerate in acidic condition (TSB, pH 2.5, 2 h incubation). These 3 strains were showed antimicrobial activity against food-borne pathogenic bacteria. These vegetative cells of 3 strains were showed a survival rate of 0.04% to 0.08% under the artificial gastric acidic condition (TSB, pH 2.5 with 1% (w/v) pepsin), but spore-forming cells were 56.29% to 84.77%. Vegetative cells of 3 strains were the least bile-resistant, while spore-forming cells of 3 strains showed higher survival rate more than 76% under artificial bile condition (TSB, 0.1% (w/v) oxgall bile). In these strains, P27 strain was finally selected as a good probiotic strain. P27 strain was tentatively identified as Bacillus amyloliquefaciens by API CHB kit and 16S rDNA sequence analysis. The results of this study suggest that B. amyloliquefaciens P27 can be used as a potential probiotic starter for fermented meat product.

• Journal of Microbiology and Biotechnology
• /
• 제2권3호
• /
• pp.220-225
• /
• 1992

Chemotaxonomic and numerical identification were carried out for an isolate of Streptomyces strain SMF13 producing thiol protease inhibitor. Fifty taxonomic unit characters were tested and the data were analyzed numerically using the TAXON program. The isolate SMF13 was identified to be a member of the cluster 5 of Streptomyces and best matched to Streptomyces omiyaensis which is a synonym of Streptomyces exfoliatus. Therefore. it was concluded that the isolate was identified to be a strain of Streptomyces exfoliatus.

• 미생물학회지
• /
• 제18권4호
• /
• pp.161-171
• /
• 1980

A mutant strain having increased productivity of both enzymes, protease and amylase, was obtained from A. flavus KU 153, isolatd from South Korea for its high protease production by successive ultra-violet light irradiation, Two glucoamylases from the mutant strain selected were purified from wheat branculture by successive salting out, followed by dialysis and column chromatography, and their characteristics were compared with those of the wild strain. Glucoamylase production of the mutant selected was increased about 3.3 times compared with the wild strain, and 2.1 times compared with the parental strain, ${\alpha}-amylase$ activity of the mutant selected was about 2 times hugher than that of the wild strain or the parental strain. Protease and cellulase productivities of the muant selected were all alike compared with those of the highly proteolytic mutant, the parental strain. Therefore, it was considered that the back mutation on the protease production did not occurred in the formation process of the glucoamylase producing mutant. Total activities of glucoamylase I and II from the mutant selected were 2.86 and 3.65 times higher compared with those from the wild strain, respectively. Considering the optimal pH-thermal stability and Km-Vmax value of glucoamylase I and II from both strains, wild and mutant, it was deduced that the characteristics of glucoamylase I and II from the wild strain did not altered during the mutation process. Therefore, it was concluded that the selected mutant did not induce the formation of another glucoamylase isozyme, or the changes in the characteristics of the glucoamylase, but induce the productivity of the same glucoamylase I and II by the action of regulatory gene.

• Journal of Microbiology and Biotechnology
• /
• 제19권1호
• /
• pp.99-107
• /
• 2009

Strain PUPC1 produces an antifungal protease as well as plant growth promoting enzymes such as 1-aminocyclopropane-1-carboxylate (ACC) deaminase and phosphatase. Morphological, cultural, and physiological characteristics as well as 16S rRNA gene-sequence-based phylogenetic analysis confirmed the taxonomic affiliation of PUPC1 as Chryseobacterium aquaticum. The optimum growth of PUPC1 was observed at pH 6.0 and $30^{\circ}C$, and maximum protease production was observed in medium B amended with 1% tryptone, 0.5% sucrose, and 0.005% $MnCl_2$. The protease was purified by ammonium sulfate precipitation, Sephadex G-75 gel filtration chromatography, and electroelution from preparative SDS-PAGE. The protease had a molecular mass of 18.5 kDa. The optimum pH and temperature stability of the protease were pH 5.0-10.0 and temperature $40-70^{\circ}C$. Chryseobacterium aquaticum PUPC1 and its protease showed a broad-spectrum antifungal activity against phytopathogenic fungi. Strain PUPC1 also exhibited plant growth promoting traits. The objective of the present investigation was to isolate a strain for agricultural application for plant growth promotion and biocontrol of fungal diseases.

• Applied Biological Chemistry
• /
• 제43권3호
• /
• pp.169-173
• /
• 2000

저온에서 높은 세척력을 갖는 호소세제의 개발을 위하여 토양으로부터 alkaline protease의 활성이 높은 균주를 분리, 동정하였으며, 호소의 성질을 조사하였다. 분리균주의 형태적 특징은 Gram 음성균 이고, 간균$(0.6{\sim}0.7{\times}1.3{\sim}2.6\;{\mu}m\;in\;size)$ 형태를 하고 있으며, 운동성을 보였다. 또한 catalase 양성, aesculin, gelatin 및 casein 분해능이 있었다. 분리균주의 세포벽 구성 성분은 meso-DAP를 함유하였으며, G+C mol 함량은 43.3%를 나타내었다. 이러한 형태적, 생리 생화학적 특성의 결과로부터 분리 균주는 Acinetobacter 속으로 동정되었다. 분리 균주를 이용한 alkaline protease의 생산은 초기 pH 10과 $40^{\circ}C$에서 36시간 배양하였을 때 3,300 D.U/mL로 최대 효소 활성을 보였으며, 최적 pH와 온도는 9와 $60^{\circ}C$이었다. 또한 본 균주에 의해 생산된 alkaline protease는 두개의 활성 band를 나타내었다.

• 한국식품영양학회지
• /
• 제13권2호
• /
• pp.171-175
• /
• 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.

• Journal of Microbiology and Biotechnology
• /
• 제11권4호
• /
• pp.558-563
• /
• 2001

A new alkalophilic strain of Bacillus pumilus JB¬05 producing bleach-stable and halo-tolerant alkaline protease was isolated from cement industry effluents in Karnataka, India. The effects of carbon and nitrogen sources on protease production by this alkalophilic strain were observed after a 30-h incubation. A high level of alkaline protease activity was obtained in the presence of starch as the carbon and peptone as the nitrogen sources. The partially purified enzyme showed an optimum temperature and pH activity at $58^{\circ}C$ and 10.5, respectively. The enzyme was completely inhibited by PMSF (95.0%) indicating it as a serine protease. It is bleach-stable as it retained 35% original activity in the presence of 10% (v/v) hydrogen peroxide at $30^{\circ}$C after 2 h and is halo-tolerant as it retained 70% original activity in the presence of 2.5 M sodium chloride at $30^{\circ}C$ after 2 h incubation.

• Journal of Animal Science and Technology
• /
• 제51권6호
• /
• pp.527-536
• /
• 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.

• 생명과학회지
• /
• 제23권12호
• /
• pp.1486-1494
• /
• 2013

Octopus vulgaris의 장관으로부터 단백질 가수분해력과 활성을 측정함으로서 높은 단백질분해효소 생성능을 가진 균을 분리하여 동정하였다. 균이 생성한 단백질분해효소는 황산암모늄침전, cellulose CM-52 양이온 교환 크로마토그래피, DEAE-Sephadex A50 음이온 교환 크로마토그래피의 3단계를 통해 정제하였다. 장관으로부터 분리한 균중 가장 높은 단백질분해효소 생성능을 가진 균은 Bacillus sp. QDV-3로 나타났으며 이균을 분리한 후 표현형 분석, 생화학적 특성, 16S rRNA 유전자염기서열분석을 통해 Bacteria역, Firmicutes문, Bacilli강, Bacillales목, Bacillaceae과, Bacillus속으로 Bacillus flexus와 99.2%의 유사성을 보이는 것으로 확인하였다. 균이 생성한 단백질 분해효소를 QDV-E로 지정하였으며 61.6 kDa의 분자량을 나타내었다. 이 효소는 pH 9.0~9.5에서 활성을 나타내었고 최적온도는 $40^{\circ}C$였으며 $50^{\circ}C$에서는 60분간 96% 이상의 활성을 보유하였다. Phenyl methyl sulfonyl fluoride (PMSF)에 의하여 활성이 억제 되었으므로 세린 알칼리성 단백 분해 효소인 것으로 결론지었다. 금속이온인 $Mn^{2+}$ 와 $Mg^{2+}$에 의하여 효소활성 상승효과를 보였으며 $Ba^{2+}$, $Zn^{2+}$, 그리고 $Cu^{2+}$에 의하여 활성이 억제되었다.