Cloning and enhanced expression of an extracellular alkaline protease from a soil isolate of Bacillus clausii in Bacillus subtilis

Document Type : Research Paper


1 Department of Microbiology, Faculty of Biological sciences, Shahid Beheshti University, P.O. Box 19395-4716, Tehran, I.R. Iran.

2 Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, P.O. Box 14965/161, Tehran, I.R. Iran.


in the detergent industry. In this study, the extracellular alkaline serine protease gene, aprE, from Bacillus
clausii was amplified by PCR and further cloned and expressed in B. subtilis WB600 using the pWB980 expression vector. Protease activity of the recombinant B. subtilis WB600 harboring the plasmid pWB980/aprE
reached up to 1020 U/ml, approximately 3-folds higher than the native B. clausii strain. Characterization of the recombinant alkaline protease by SDS-PAGE and zymogram analyses indicated a molecular weight of
31 kDa. DNA sequence analysis and the deduced amino acid sequence revealed 98% homology with the
extracellular alkaline serine protease from B. clausii KSM-K16.