Characterization of Extracellular Proteolytic Enzyme of Isolated Psychrotrophic Bacteria from Cheddar Cheese

체다치즈에서 분리한 내냉성미생물의 단백질분해효소의 특성

  • Kim, Eun-Ah (Seoul Dairy Co-op, Institute of Dairy Food Research) ;
  • Lee, Kyung-Wook (Seoul Dairy Co-op, Institute of Dairy Food Research) ;
  • Boo, Won-Back (Seoul Dairy Co-op, Institute of Dairy Food Research) ;
  • Lee, Hyung-Hoan (Department of Biology, Kon Kuk University) ;
  • Kwak, Hae-Soo (Seoul Dairy Co-op, Institute of Dairy Food Research)
  • 김은아 (서울우유협동조합 기술연구소) ;
  • 이경욱 (서울우유협동조합 기술연구소) ;
  • 부원백 (서울우유협동조합 기술연구소) ;
  • 이형환 (건국대학교 생물학과) ;
  • 곽해수 (서울우유협동조합 기술연구소)
  • Published : 1991.08.01

Abstract

Psychrotrophs producing protease were isolated during ripening periods of Cheddar cheese and one of them containing the highest protease activity was identified as Pseudomonas fluorescens 65. The extracelluar proteolytic enzyme was partially purified from P. fluorescens 65 through the Sephadex G-100 gel filtration. The protease was eluted between 190 ml and 230 ml of elution volume of sodium phosphate buffer. The purified protease showed a single band in SDS-PAGE and its molecular weight was 47,000. The composition of amino acid for the protease was determined and the most abundant amino acids were glutamic acid (14.96%) and serine (13.86%). The optimum temperature and pH for the activity was $45{\sim}50^{\circ}C$ and 6.0, respectively.