Abstract: β1 toxin gene was amplified from Clostridum perfringens type B C58-1 strain by polymerase chain reaction (PCR),PCR products were connected to pMD18-T vector screening positive clones,and then cleaved with restriction endonucleases BamHⅠand SalⅠ,the 927 bp gene fragment was recovered and inserted into the same site of pET-32a vector.The recombinant plasmid pETβ927 was studied in detail by restriction endonuclease analysis and nucleotide sequencing.The recombinant plasmid could produce β1 toxin protein by SDS-PAGE.Expressed products were purified by pre-installed column of His-Trap FF,the size and distribution of the target protein were detected by SDS-PAGE,and its immunorectivity was confirmed by Western blotting.The results showed that the β1 toxin gene was 1 011 bp and the homologies with B and C type Clostridum perfringens protein sequences of GenBank were greater than 99.4%;In SDS-PAGE analysis,the fusion protein was 54 ku as expected and distributed in ultrasonic lysis supernatant as well as in inclusion bodies,but mainly existed in inclusion bodies.Western blotting analysis showed that the β1 toxin protein had a good immunorectivity with specific serum antibody.

Key words: Clostridum perfringens type B C58-1 strain; β1 toxin gene; cloning and expression