Cloning of nattokinase gene and expression in E. coli

In this study, nattokinase gene was amplified by PCR using bacillus subtilis chromosomal DNA as template and cloned into expressed vectoro pBV220. After transforming recombinant plasmid into E. coli HB101, the recombinant strain was yielded. It was proved that expression products was secretive and expression protein was 12% of total cell protein by SDS-PAGE. Optimum culture time and including time was determined as 6h and 5h respectively. The plasmid stability studies showed that recombinant plasmid has excellent segregational stability but the structural stability was not good in the host cell.