Résumé
Schistosomiasis is one of a few endemic and infectious diseases,which are controlled by the specific prevention and control institutions in China.Through the review of historical data,this paper describes the construction,continuation and changes of schistosomiasis prevention and control institutions in different historical periods and systems,and analyzes and evalu-ates its historical function,contribution and status.
Résumé
In this study, nattokinase gene was amplified by PCR using bacillus subtilis chromosomal DNA as template and cloned into expressed vector 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 inducing 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.