Cloning of Fibrinolytic Enzyme Gene from Bacillus subtilis Isolated from Cheonggukjang and Its Expression in Protease-deficient Bacillus subtilis Strains

Cloning of Fibrinolytic Enzyme Gene from Bacillus subtilis Isolated from Cheonggukjang and Its Expression in Protease-deficient Bacillus subtilis Strains

Bacillus subtilis CH3-5 was isolated from cheonggukjang prepared according to traditional methods. CH3-5 secreted at least four different fibrinolytic proteases (63, 47, 29, and 20 kDa) into the culture medium. A fibrinolytic enzyme gene, aprE2, encoding a 29kDa enzyme was cloned from the genomic DNA of CH3-5, and the DNA sequence determined. aprE2 was overexpressed in heterologous B. subtilis strains deficient in extracellular proteases using a E. coli-Bacillus shuttle vector. A 29 kDa AprE2 band was observed and AprE2 seemed to exhibit higher activities towards fibrin rather than casein.