in the detergent industry. In this study, the extracellular alkaline serine protease gene, aprE, from Bacillusclausii 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/aprEreached up to 1020 U/ml, approximately 3-folds higher than the nativ...