Characteristics of Protease Produced by Bacillus subtilis PCA 20-3 isolated from Korean Traditional Meju

전통 메주로부터 분리한 Bacillus subtilis PCA 20-3 유래의 Protease 생산과 특성

  • Lim, Seong-Il (Division of Chemistry and Biotechnology, Korea Food Research Institute) ;
  • Kim, Hyun-Kyu (Division of Chemistry and Biotechnology, Korea Food Research Institute) ;
  • Yoo, Jin-Young (Division of Chemistry and Biotechnology, Korea Food Research Institute)
  • 임성일 (한국식품개발연구원 생물공학연구부) ;
  • 김현규 (한국식품개발연구원 생물공학연구부) ;
  • 유진영 (한국식품개발연구원 생물공학연구부)
  • Published : 2000.02.28

Abstract

Protease production and its characteristics were investigated with Bacillus subtilis PCA20-3 which was isolated from Korean traditional meju. The optimum culture conditions of Bacillus subtilis PCA20-3 for the production of the protease were as follow: 0.2% soytone, 2% starch, 0.1% $(NH_4)_2SO_4,\;0.2%\;CaCl_2,\;0.01%\;yeast\;extract,\;0.1%\; K_2HPO_4,\;0.1%\;KH_2PO_4,\;pH\;7.0,\;30^{\circ}C$ and 20 hrs. The optimum pH and temperature for enzyme activity of protease producing Bacillus subtilis PCA20-3 were pH 8.0-10.0 and $55^{\circ}C$, respectively. The enzyme was relatively stable at pH $6.0{\sim}11.0$ and at temperature below $50^{\circ}C$. The activity of the enzyme was inhibited by $Fe^(2+)\;and\;Cu^(2+)$. 2 mM phenymethanesulfonyl fluoride inhibited 89.2% of enzyme activity. This indicates that the enzyme is serine protease. The $K_m$ value was $5\;{\times}\;10^{-4}\;M,\;V_{max}\;value\;was\;100\;{\mu}g/min$. This enzyme hydrolyzed casein more rapidly than bovine serum albumin.

Keywords

Bacillus subtilis PCA20-3;protease;meju