Purification and Characterization of a Proteolytic Enzyme from Bacillus subtilis M2-4

  • LIU Chenjian
    Faculty of Life Science and Technology, Kunming University of Science and Technology,
  • NAGANO Hiroko
    Faculty of Education, Gifu University

Bibliographic Information

Other Title
  • Bacillus subtilis M2-4由来タンパク分解酵素の精製とその性質

Search this article


The proteolytic enzymes produced by naturally occurring microorganisms during the bread-making process were investigated. We isolated one Gram-positive and aerobic endospore-forming rod bacterium designated B. subtilis M2-4 producing a proteolytic enzyme from traditional and naturally fermented wheat flour. An analysis of the 16S rRNA sequence of the isolated strain revealed it to be 99% identical to Bacillus subtilis. We purified the proteolytic enzyme to electrophoretic homogeneity from the culture supernatant by column chromatography. The calculated molecular mass of the purified enzyme determined by gel filtration was 33 kDa. The proteolytic enzyme showed optimal activity at 55°Cand pH 11.0, and was stable below 50°C and in the pH range of 5.0-11.0. The N-terminal amino acid sequence of the purified protease from B. subtilis M2-4 was AQSVPYGISQIKAPA, the same as other subtilisins. However, this is the first report of its isolation from traditional fermented wheat flour. The purified protease digested acid casein into fragments with hydrophilic and hydrophobic amino acids at the C-terminal, in particular Arg, Glu, Val and Ile.


Citations (1)*help

See more


See more

Details 詳細情報について

Report a problem

Back to top