A method for creating streptomyces lividans cloned with salmon calcitonin (SCT) gene uses gene engineering technique, where plasmid p(IJ680) is vector. A PCR (polymerase reaction) amplification technique is used to obtain SCT gene and secretory signal peptide melc1 gene. Using T1DNA ligase can connect CT gene, melc1 gene and p(UC19) plasmid DNA, and after transforming to colibacillus, SCT-mele1 DNA fragment is obtained. After the fragment is connected to plasmid p(IJ680) as Streptomyces lividans' vector, it is transformed and cloned to the Streptomyces lividans TK54. By selecting the transformatant resisting thiostrepton and extracting recombined plasmid p(MS680), the Streptomyces lividans cloned with salmon calcitonin TK54-MS680 is obtained. After fermentation culture, efficient secretory expressed salmon calcitonin is obtained with stable inheritance. |