Bacillus licheniformis CICIM B5102 was used for the commercial production of alkaline protease. The full-length gene apr encoding the alkaline protease was amplified via polymerase chain reaction (PCR) using the genomic DNA of B. licheniformis CICIM B5102 as a template. The apr gene was cloned into plasmid pUB110, resulting in the recombinant plasmid pUB-apr, which was then transformed into Bacillus amyloliquefaciens CICIM B4803. The protease productivity was significantly improved in the transformants of B. amyloliquefaciens CICIM B4803. A transformant with high alkaline protease productivity was selected, and the alkaline protease productivity of the strain increased by 46% when compared with that of wild-type B. licheniformis CICIM B5102.

Key word: Alkaline protease, Bacillus amyloliquefaciens, Bacillus licheniformis.