• 한국미생물·생명공학회지
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• 제34권2호
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• pp.150-157
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• 2006

스웨덴 스톡홀름의 항구부근 토양시료로부터 분리한 Bacillus sp. SMMJ-2는 단백질 분해활성이 높은 균주로써 특히 keratinolytic protease 생산성이 우수한 균주이다. 효소생산을 위한 최적 배지조성은 0.7% $K_2HPO_4$, 0.2% $KH_2PO_4$, 1.0% fructose, 1.2% soybean meal(roasted), 그리고 0.01% $Na_2CO_3$ 이었으며 배양초기 pH는 7.0, 배양온도는 30$^{\circ}C$에서 200 rpm조건일 때 효소생산이 가장 우수하였으며 이때의 활성은 105 units/ml/min로 조사되었다.

• 미생물학회지
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• 제26권4호
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• pp.355-361
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• 1988

성장속도가 빠르고포지형성이 우수한 방사균 일주를 토양에서 분리한 뒤 분리균의 특성을 조사한 결과 세포외 단백질 분해 효소가 중성과 알카리성의 두 종류가 생성되었으며 $\beta$-lactamase도 생성함을 알았다. 이 균주를 acriflarin 또는 NTG로서 처리하여 얻은 변이주는 포자의 형성, $\beta$-lactamase의 생성 및 protease의 생합성 능력이 소실 또는 크게 저하되었다. 일단계의 변이주 취득에서 동시에 형질의 변화가 다양하게 나타난 원인을 규명한 결과 호알카리성 protease의 생합성이 크게 저하되었음을 알았다. 따라서 방선균에서 포자형성과 호알카리성 protease의 활성이 일정한 연관성이 있을 것으로 판단되었다.

• 미생물학회지
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• 제14권2호
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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.

• 미생물학회지
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• 제14권2호
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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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• 제21권12호
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• pp.1250-1256
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• 2011

In this study, Bacillus licheniformis cells were immobilized by entrapment in calcium alginate beads and were used for production of alkaline protease by repeated batch process. In order to increase the stability of the beads, the immobilization procedure was optimized by statistical full factorial method, by which three factors including alginate type, calcium chloride concentration, and agitation speed were studied. Optimization of the enzyme production medium, by the Taguchi method, was also studied. The obtained results showed that optimization of the cell immobilization procedure and medium constituents significantly enhanced the production of alkaline protease. In comparison with the free-cell culture in pre-optimized medium, about 7.3-fold higher productivity was resulted after optimization of the overall procedure. Repeated batch mode of operation, using optimized conditions, resulted in continuous production of the alkaline protease for 13 batches in 19 days.

• Journal of Microbiology and Biotechnology
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• 제10권1호
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• pp.103-106
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• 2000

Bacillus cereus KCTC 3674 excretes at least two kinds of extracellular proteases into the growth medium. Two major bands of the protease activity with molecular weights of approximately 100 and 38 kDa were obtained after gelatin-SDS-PAGE. The protease with a molecular weight of 38kDa was identified as an extracellular neutral (metallo-) protease. The neutral protease was quite thermostabile but labile to alkaline pH. On the contrary, the 100-kDa protease was thermolabile but stable to alkaline pH. The production of 38-kDa neutral protease was strongly affected by temperature, oxygen, carbonylcyanied m-chlorophenylhydrazone(CCCP) that was defined as a protonophofre, and cerulenin which inhibited lipid synthesis and caused changes in the membrane composition. On the other hand, the production of the 100-kDa protease was strongly affected by only temperature and cerulenin. Quinacrine (0.2 mM), which inhibits the penicillinase-releasing proteases of Bacillus licheniformis, had no effect, whatsoever, on the production of extracellular proteases in B.cereus KCTC 3674.

• 미생물학회지
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• 제40권1호
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• pp.43-48
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• 2004

본 연구에서는 우모의 생물학적 처리를 위하여 keratinolytic pretense를 생성함으로써 우모를 분해할 수 있는 Bacillus megaterium을 붕괴된 우모로부터 분리하였다. 본 균주에 의한 keratinolytic pretense생산 최적배지 조성 및 배양조건은 0.2% glucose, 0.8% skim milk, 0.05% NaCl, 0,01% $(K_2HPO_4$, 0.02%, $(KH_2PO_4$, 0.01% $MgCl_2$, 초기 pH 6.5 및 $25^{\circ}C$이었다. 특히, skim milk의 첨가는 효소 생산에 가장 효과적이었다. 최적조건에서 배양 5일만에 269 U/ml의 효소가 생산되었으며, 배양 6일경 98%의 우모가 분해되었다.

• Journal of Microbiology and Biotechnology
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• 제19권4호
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• pp.378-386
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• 2009

A sequential optimization strategy, based on statistical experimental designs, is employed to enhance the production of alkaline protease by a Bacillus pseudofirmus local isolate. To screen the bioprocess parameters significantly influencing the alkaline protease activity, a 2-level Plackett-Burman design was applied. Among 15 variables tested, the pH, peptone, and incubation time were selected based on their high positive significant effect on the protease activity. A near-optimum medium formulation was then obtained that increased the protease yield by more than 5-fold. Thereafter, the response surface methodology(RSM) was adopted to acquire the best process conditions among the selected variables, where a 3-level Box-Behnken design was utilized to create a polynomial quadratic model correlating the relationship between the three variables and the protease activity. The optimal combination of the major medium constituents for alkaline protease production, evaluated using the nonlinear optimization algorithm of EXCEL-Solver, was as follows: pH of 9.5, 2% peptone, and incubation time of 60 h. The predicted optimum alkaline protease activity was 3,213 U/ml/min, which was 6.4 times the activity with the basal medium.

• 한국미생물·생명공학회지
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• 제30권4호
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• pp.346-351
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• 2002

토양으로부터 pretease활성이 우수한 균주를 선별하여 형태학적, 생화학적 동정과정 및 16 rRNA염기서열 분석 등의 방법을 이용하여 Bacillus sp. DS-1으로 동정하였다. Bacillus sp. DS-1은 초기 배지의 pH가 7.0인 조건에서 정지기에서 가장 높은 활성을 나타내었다. Bacillus sp. DS-1으로부터 protease를 생산하기 위해 탄소원으로는 1% glucose, 질소원으로는 1% yeast extract를 첨가할 때 대조구와 비교하여 각각 20%와 30% 더 효과적인 것으로 나타났다. Bacillus sp. DS-1이 생산하는 protease의 최적활성은 55$^{\circ}C$와 pH 7.0이었다. 1 mM의 EDTA첨가에 의해 protease활성이 84%실활 되었고 이 결과로부터 Bacillus sp. DS-1의 상등액에 존재하는 주된 protease 활성은 metalloprotease임을 알 수 있었다.

• Journal of Animal Science and Technology
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• 제51권6호
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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.