• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.346-351
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• 2002

A bacterium producing the neutral pretense was isolated from soil, and was identified as Bacillus sp. DS-1 by 16S rRNA sequence comparison and biochemical determinations. The production of protease from Bacillus sp. DS-1 was increased 20% and 30% by the additions of 1% glucose and 1% yeast extract, respectively. The optimum pH and temperature for the protease activity were pH 7.0 and 55$^{\circ}C$. Bacillus sp. DS-1 produced a metalloprotease as a major protease in culture medium, since the pretense activity in culture supernatant was inhibited by the presence of 1 mM EDTA significantly.

• Microbiology and Biotechnology Letters
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• v.22 no.1
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• pp.59-64
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• 1994

The production and the characteristics of protease produced by Bacillus sp. SH-8 and Bacillus sp. SH-8M were investigated under the different pH conditions. Bacillus sp. SH-8 and Bacillus sp. SH-8M showed the maximum activity of protease at 60 hours(70 units/ml) AND 96 houre(50 units/ml) cultivation, respectively, under the alkaline condition(pH 10.2). However, Bacillus sp. SH-8M exhibited the maximum activities in 8 days cultivation at pH 6.9 and in 6 days cultivation at pH 7.7 Bacillus sp. SH-8M showed the protease activity at the pH change from alkaline to neutral condition, whereas Bacillus sp. SH-8 did not. In addition. all the enzymatic characteristics of protease produced by Bacillus sp. SH-8 and Bacillus sp. SH-8M were similar with the regardless of different pH conditions.

• KSBB Journal
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• v.4 no.2
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• pp.128-133
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• 1989

Carbon sources and nitrogen sources are known to be very important in protease production by microorganisms. The effects of carbon source and nitrogen source on protease biosynthesis by Bacillus licheniformis were investigated using batch cultures. As initial carbon and nitrogen concentrations of culture medium increased, the specific growth rate of Bacillus licheniformis was increased, while the specific protease production rate was decreased. From the results of batch cultures, a mathematical model which considers the effects of carbon source and cnitrogen source was proposed and the methods to increase the productivity of protease were discussed.

• Microbiology and Biotechnology Letters
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• v.19 no.2
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• pp.116-121
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• 1991

A bacterial strain KN, which highly produced a protease, was isolated from several soil samples and identified to to belong to the genus Bacillus. We selected mutant strain Bacillus sp. KN103N, which was hyperproducer of protease and was resistant to D-cyclowerine, from the strain KN by several steps of mutagenesis. Neutral protease productivity of mutant strain KN103N was about 55 times as much as that of the original strain KN. The optimum pH and temperature for the enzyme activity were 7.0 and 50$^{\circ}C$, respectively and the enzyme was relatively stable at pH6.0~8.0 and below 40$^{\circ}C$. The enzyme was inactivated by EDTA, but not by DFP. These results indicate that the enzyme from Bacillus sp. KN103N was a neutral (metallo-) protease.

• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.150-157
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• 2006

Bacillus sp. SMMJ-2 producing extracellular keratinolytic protease was isolated from the Swedish soils. The optimal culture conditions for production of keratinolytic protease by Bacillus sp. SMMJ-2 were investigated. The optimal medium compositions for the keratinolytic protease production were 0.7% $K_2HPO_4$, 0.2% $KH_2PO_4$, 1.0% fructose,1.2% soybean meal (roasted), and 0.01% $Na_2CO_3$. Optimal initial pH and temperature for the production of keratinolytic protease were 7.0 and 30$^{\circ}C$, respectively. The keratinolytic protease production showed a maximum of 105 units/ml/min after 72 hours cultivation under the optimal culture conditions.

• Korean Journal of Microbiology
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• v.40 no.1
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• pp.43-48
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• 2004

Bacillus megaterium F7-1 producing keratinolytic protease was isolated from decayed chicken feather. The optimal culture conditions for the production of keratinolytic protease by B. megaterium F7-1 were investigated. The composition of optimal medium for the keratinolytic protease was 0.2% glucose, 0.8% skim milk, 0.05% NaCl, 0.01 % $(K_2HPO_4$, 0.02%, $(KH_2PO_4$ and 0.01 % $MgCl_2$. Especially, skim milk was found to be the most effective compound in keratinolytic protease production. The optimal temperature and initial pH were 6.5 and $25^{\circ}C$, respectively. The keratinolytic protease production under optimal condition reached a maximum of 269 U/ml after 5 days of cultivation. B. megaterium F7-1 degraded 98% of the feather used in the optimized medium within 6 days.

• Applied Biological Chemistry
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• v.44 no.4
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• pp.246-250
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• 2001

In order to produce alkaline protease, psychrotrophic Bacterium which have high enzyme activity, was isolated by using enrichment culture from soil samples and identified as genus Bacillus sp. The optimal pH and temperature for the enzyme activity were pH 6 and $40^{\circ}C$. The temperature range of high enzyme activity was $20{\sim}40^{\circ}C$. The optimal initial pH of culture condition for enzyme was pH 6. The most favorable carbon and nitrogen sources for the production of protease by Bacillus sp. WRD-2 were 3% maltose and 4% yeast extract, respectively.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1054-1059
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• 2005

An extracellular protease was identified from Bacillus subtilis KCCM 10257 by N-terminal sequencing and mass spectral analysis. The molecular mass of the extracellular protease was estimated to be 28 kDa by SDS-PAGE. Sequencing of the N-terminal of the protease revealed the sequence of A(G,S,R)QXVPYG(A)V(P,L)SQ. The N-terminal sequence exhibited close similarity to the sequence of other proteases from Bacillus sp. A mass list of the monoisotopic peaks in the MALDI-TOF spectrum was searched after peptide fragmentation of the protease. Six peptide sequences exhibiting monoisotopic masses of 1,276.61, 1,513.67, 1,652.81, 1,661.83, 1,252.61, and 1,033.46 were observed from the fragmented protease. These monisotopic masses corresponded to the lytic enzyme L27 from Bacillus subtilis 168, and the Mowse score was found to be 75. A doubly charged Top product (MS) at a m/z of 517.3 exhibiting a molecular mass of 1034.6 was further analyzed by de novo sequencing using a PE Sciex QSTAR Hybrid Quadropole-TOF (MS/MS) mass spectrometer. MS/MS spectra of the Top product (MS) at a m/z of 517.3 obtained from the fragmented peptide mixture of protease with Q-star contained the b-ion series of 114.2, 171.2, 286.2, 357.2, 504.2, 667.4, 830.1, and 887.1 and y-ion series of 147.5, 204.2, 367.2, 530.3, 677.4, 748.4, 863.4, and 920.5. The sequence of analyzed peptide ion was identified as LGDAFYYG from the b- and y-ion series by de novo sequencing and corresponded to the results from the MALDI-TOF spectrum. From these results the extracellular protease from Bacillus subtilis KCCM 10257 was successfully identified with the lytic enzyme L27 from Bacillus subtilis 168.

• Microbiology and Biotechnology Letters
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• v.23 no.3
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• pp.322-328
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• 1995

A thermophilic bacteria showing proteolytic activity against defatted soybean was isolated from soil. It was identified as Bacillus amyloliquefaciens based on its morphological and physiological characteristics. The Bacillus amyloliquefaciens NS 15-4 was cultivated at 50$\circ$C by rotary shaking in a medium containing defatted soybean. An extracellular protease from this strain was purified to homogeneity by ammonium sulfate precipitation, ion exchange, and hydrophobic interaction chromatographies. The molecular weight of the enzyme was estimated to be approximately 30,000 by SDS-PAGE and the N-terminal amino acid sequence of the enzyme was turned out to be AQSVPYGISQIKAPA. The optimum temperature and pH for the enzyme reaction were 60$\circ$C and 11, respectively, and its thermostability was increased by the addition of calcium ion. The enzyme was inactivated by phenylmethylsulfonylfluoride, suggesting it be a serine protease. Comparing with other commercial proteases, the enzyme showed relatively high proteolytic activity against defatted soybean, a water-insoluble protein substrate.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.3
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• pp.186-191
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• 2005

In this study, a microorganism-produced protease was used to improve the quality of fabrics. First, the protease-producing bacteria were isolated from soils, and one of them was selected and identified as Bacillus sp. SJ-121. The optimal medium composition for its growth and protease production was determined to be as follows: glucose 1g/L, soybean meal 0.5g/L, soy peptone 0.5, $K_2HPO_4\;0.2,\;MgSO_4\cdot7H_2O\; 0.002,\;NaCl\;0.002,\;and\;Na_2CO_3g/L$. Also, the optimal temperature for the production of the protease by Bacillus sp. SJ-121 was about $40^{\circ}C$ at pH 7. The wool and silk were treated with the protease from Bacillus sp. SJ-121. Following the protease treatment, changes in the surface of a single yarn of the fabrics were observed by both an optical microscope and a scanning electron microscope (SEM). Changes in the K/S value of the wool and silk were measured by spectrophotometric analysis, in order to determine the amount of dye uptake in the fabrics. We also performed a tensile strength examination in order to determine the degree and nature of mechanical changes in single yarns of the wool and silk fabrics. By increasing the protease treatment time to 48 h, the dyeing characteristics of the fabrics were enhanced, and the surfaces of the single yarns of the fabrics became smoother, due to the removal of soil and scale in them. However, no mechanical changes were detected in the fabrics. Therefore, we suggest that proper treatment of the protease produced by Bacillus sp. can improve the quality of silk and wool.