• 미생물학회지
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• 제27권1호
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• pp.43-47
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• 1989

Characteristics and roles of protease released during the germination of Dictyostelium discoideum spores were investigated. When geat activated, the spores germinated, progressively releasing the protease into the extracellular medium. The protease activity exhibited high at pH 2.5. When cyclogeximide was added to culture, complete germination (emergence) and protease release were stopped. Addition of purified nonspecific protease to culture speeded up germination. These results suggest that excreted protease may play a role in removal of the spore wall.

• 한국미생물·생명공학회지
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• 제18권4호
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• pp.344-351
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• 1990

계명활성제 내성이 있으면서 호알카리성인 protease를 생산하는 미생물을 토양에서 분리하였다. 분리된 미생물을 형태적, 생리학적, 화학분류학적 및 5S RNA 분석으로 동정한 결과 Bacillus sp.인 것으로 판명되었다. 호알카리성 protease는 황산암모늄 분획, DEAE-Cellulose, CM-Cellulose, Sephadex G-100 column chromatogrphy로 분리, 정제하였다. 정제된 호알카리성 protease는 casein에 대하여 pH6.0에서 11.0 사이에서 안정성을 나타내었다. 분리된 효소의 작용 최적 온도는 $55^{\circ}C$이었다. 이 효소는 diisopropyl fluorophosphate(DFP)로 완전히 불활성화되는 것으로 보아 serine protease로 추정되며 계면활성제의 존재하에서도 안정하였다.

• 생명과학회지
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• 제31권8호
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• pp.761-770
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• 2021

본 연구에서는 반응표면분석법을 이용하여 전통발효식품인 막걸리로부터 분리한 Bacillus amyloliquefaciens SRCM115785 균주에 대하여 protease 생산량을 증가시키기 위한 배지의 최적 농도를 확립하고자 하였다. 선정한 11개의 배지 성분 중 각 성분이 protease 생산에 미치는 영향에 대한 분석을 위해 Plackett-Burman design (PBD)를 설계하여 통계분석한 결과 glucose, yeast extract, beef extract를 protease 생산 향상을 위한 요인으로 최종 선별하였다. 선별된 3개의 성분에 대해 protease 생산을 위한 각 성분별 최적 농도를 결정하기 위해 central composite design (CCD)분석을 설계하여 protease 최대 생산을 위한 각 배지조성별 농도는 glucose 6.75 g/l, yeast extract 12.42 g/l, beef extract 17.48 g/l로 예측되었다. ANOVA 분석을 통해 실험모델의 적합성을 증명하였고, 설계한 최적배지에서 반복실험을 진행하여 protease 생산량을 측정한 결과 예측값과 매우 유사한 값을 나타냄을 확인하였다. 최종적으로 일반 배지에 비해 137% 환이 증가하였으며, 추가로 정량 분석 결과 기존 25.72 U/ml 대비 59.28 U/ml로 230.47% 증가함을 확인하였다. 본 연구를 통해 protease 생산량 증가를 위한 배지 성분의 최적화를 확립하였고, 이를 바탕으로 산업용 효소로서 protease의 효율적인 활용방안에 대한 기초자료로서 활용될 수 있을 것으로 기대된다.

• 한국미생물·생명공학회지
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• 제42권3호
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• pp.293-296
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• 2014

본 논문에서는 극지미생물의 저온 활성 protease 생산에 관한 연구를 수행하였다. 먼저 protease를 생산하는 극지미생물인 PAMC 25641, 25614, 25719, 25617을 16s rDNA 염기서열 분석을 이용하여 동정하였다. 그 후, 다양한 온도($5^{\circ}C$, $10^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$)에서의 성장률 및 protease activity, specific activity를 확인하였다. 각 미생물의 온도별 성장률은 대체로 비슷한 경향을 보였으나 25617은 $20^{\circ}C$에서 급격한 성장률 증가를 확인할 수 있었다. 또한, specific activity는 25641이 5, 15, $20^{\circ}C$에서 가장 높은 specific activity를 갖는 것을 확인하였다.

• 한국미생물·생명공학회지
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• 제23권2호
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• pp.145-149
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• 1995

For the purpose of developing a new biodegradable detergent, we have isolated a gene encoding wide-range temperature applicable alkaline protease from Xanthomonas sp. YL-37 (Lee et al., 1994, Kor. J. Appl. Microbiol. Biotechnol.). An alkaline protease gene was isolated from the gene bank that was prepared from the chromosomal DNA of Xanthomonas sp. YL-37. From the results of agarose gel electrophoresis and a restriction enzyme mapping, a 2.7 kb DNA fragment containing the alkaline protease gene was inserted in the plasmid pUC9. Extracellular activity of a clone having alkaline protease gene was detected on SDS-polyacrylamide gel with activity staining assay. The molecular weight of alkaline protease was determined to be about 64 kDa from 11% SDS-PAGE analysis. Alkaline protease activity, produced from E. coli which harboring the plasmid, showed no difference at reaction temperature 20, 30 and 40$\circ$C, respectively. This result showed that alkaline protease produced from E. coli harboring the plasmid was apparently the same as that of Xanthomonas sp. YL-37.

• 미생물학회지
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• 제18권2호
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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.

• 미생물학회지
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• 제10권2호
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• pp.69-72
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• 1972

The studies of neutral protease which was obtained by passing through Sephadex A-50 had been reported not long ago. Since that time the author also conducted the research to be investigated the physical properties of acid protease absorbed by Sephadex A-50. The results are summarized as follows : 1) Cultivating Aspergillus oryza SHW-131 on a wheat bran medium, the acid protease including neutral protease is very sensitive for temperature. 3) Activity of acid protease is very sensitive for temeprature. 3) This enzyme was proved, what is called, to be a sort of weak acid protease. It's optimum pH was lied in about 4.5. 4) A range of pH for stability is far more narrow than any other protease. 5) The acid protease is dropped by EDTA solution in its activity.

• Korean Chemical Engineering Research
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• 제53권4호
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• pp.524-529
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• 2015

본 논문에서는 저온활성 protease의 생산을 최적화하기 위하여 극지 미생물인 Enterobacteriaceae sp. PAMC 25617의 반응표면분석법을 이용한 배지의 최적화를 수행하였다. One-factor-at-a-time 방법을 이용하여 yeast extract, TritonX-100이 protease의 생산에 영향을 미치는 주요인자인 것을 확인하였다. 물리적인 환경 요인으로 pH를 추가하여 반응표면분석 방법을 이용한 최대 protease 생산 농도를 갖는 각 인자들의 농도를 확인한 결과 5 g/L peptone, 3 g/L malt extract, 10 g/L $C_6H_{12}O_6$, 6.690 g/L yeast extract, 0.018 g/L TritonX-100의 농도에 pH 6.777의 조건에서 미생물을 배양하였을 경우, 최대 10.049 U/L의 protease가 생산될 수 있는 것으로 예측되었다. 실제 배양 결과 8.03 U/L의 protease가 얻어졌으며, 최적화 이전의 생산농도와 비교하여 150% 이상의 증가를 이루었다. 결과적으로 배지최적화를 통한 protease 생산량의 증가에 반응표면분석법의 적용이 유용하다는 것을 확인할 수 있는다. 이러한 결과로부터, 배지 최적화를 이용한 극지 미생물 유래 cold-adapted protease 생산량의 증가가 여러 산업 분야에서 유용하게 이용될 수 있을 것으로 생각된다.

• 미생물학회지
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• 제18권1호
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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.

• 미생물학회지
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• 제24권1호
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• pp.32-37
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• 1986

In fermentation studies it revealed that Streptomyces sp. SMF 3001 started to synthesize extracellular alkaline protease from early exponential phase of cell growth. The biosynthesis of the alkaline protease was greatly induced by skim milk as a sola nitrogen source and further stimulation was observed under inorganic sulphur limited culture. However, it was found that the biosynthesis was apparently repressed by $NH_4^+$ and free amino acids, specially by cysteine. It was considered that the strain SMF 301 of Streptomyces sp. would produce the alkaline protease for the uptake of sulphur compounds from protein contained in the culture broth.