• Title/Summary/Keyword: SMMJ-2

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Isolation of Mutant Strains from Keratinase Producing Bacillus subtilis SMMJ-2 and Comparision of Their Enzymatic Properties (Keratinase 생산균 Bacillus subtilis SMMJ-2의 변이주 분리와 효소학적 특성 비교)

  • Ko, Hee-Sun;Kim, Hyun-Soo
    • KSBB Journal
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    • v.25 no.5
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    • pp.429-436
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    • 2010
  • Keratinase is widely used in certain industrial applications. The present study sought to improve the culture conditions of Bacillus subtilis SMMJ-2 to facilitate mass production of keratinase. Strain SMMJ-2 was irradiated by ultraviolet light and the resulting isolates were tested for keratinase activity. Isolates displaying elevated keratinase activity were selected and used to determine the optimum temperature (24, 30, 37, 45, $55^{\circ}C$) for bacterial keratinase production during a 4 day incubation period. The highest enzyme activity (55 units/mL/min), from a Bacillus subtilis SMMJ-2 mutant (mutant No. 2) was demonstrated following incubation at $30^{\circ}C$. The effects of carbon and nitrogen sources on keratinase production were confirmed by measuring the enzyme activity from the culture broth of the mutant strain cultured in various media containing different carbon source and nitrogen sources during a 4 day period. The optimal medium composition for producing keratinase consisted of 1% glucose, 0.7% $K_2HPO_4$, 0.2% $K_2HPO_4$, and 1.2% soybean meal. Optimal initial pH and temperature for producing keratinase were 7.0 and $30^{\circ}C$, respectively. Keratinases produced by B. subtilis SMMJ-2 and the mutant No. 2 were purified from the culture broth which used soybean meal as a nitrogen source. Membrane ultrafiltration, DEAE-sephacel ion exchange and Sephadex G-100 gel chromatography were used to purify the enzymes. The purified keratinases from both B. subtilis SMMJ-2 and the mutant No. 2 showed single bands and their molecular weights were estimated as 28 kDa and 42 kDa, respectively on SDS-polyacrylamide gel electrophoresis.

Optimization of Keratinolytic Protease Productions from Bacillus sp. SMMJ-2 (Bacillus sp. SMMJ-2의 Keratinolytic protease 생산최적조건)

  • Park Sung-Min;Yu Tae-Shick
    • 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.

Selection and Cultural Characteristics of Whole Chicken Feather-Degrading Bacterium, Bacillus sp. SMMJ-2 (Whole Chicken Feather-Degrading Keratinolytic Protease 생산균주의 분리 및 특성)

  • Park Sung-Min;Jung Hyuck-Jun;Yu Tae-Shick
    • Microbiology and Biotechnology Letters
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    • v.34 no.1
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    • pp.7-14
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    • 2006
  • Feather, generated in large quantities as a byproduct of commercial poultry processing, is almost pure keratin, which is not easily degradable by common professes. Four strains, SMMJ-2, FL-3, NO-4 and RM-12 were isolated from soil for production of extracellular keratinolytic protease. They were identified as Bacillus sp. based on their morphological and physiological characteristics. They shown high protease activity on 5.0% skim milk agar medium and produced a substrate like mucoid on keratin agar medium. Bacillus sp. SMMJ-2 had a faster production time for producing keratinolytic protease than other strains. This strain did not completely degrade whole chicken feather for five days in basal medium but completely degraded whole chicken feather when supplied with nitrogen source for 40hours in keratinolytic producing medium ($0.7%\;K_{2}HPO_{4},\;0.2%\;KH_{2}PO_{4},\;0.1%$ fructose, 1.2% whole chicken feather, $0.01%\;Na_{2}CO_3$, pH 7.0). When supplied with chicken feather as nitrogen source, keratinolytic protease activity was 89 units/ml/min. When soybean meal was used as nitrogen source, the keratinolytic protease production reached a maximum of 106 units/ml/min after 48 hours under $30^{\circ}C$, 180 agitation. To isolate the keratinolytic protease, the culture filtrate was precipitated with $(NH_4)_{2}SO_4$ and acetone. The recovery rate of keratinolytic protease was about 96% after treatment with 50% acetone. The enzyme was stable in the range of $30{\sim}50^{\circ}C$ and pH $6.0{\sim}12.0$.