中国生物工程杂志

To characterize the promoter and signal-peptide activity of expression vector pGPST, lacZ gene was inserted into vector pGPST yielding the recombinant plasmid pGPST-lacZ and it was translated into Bacillus subtilis AS.1700 by electroporation. The active of β-galactosidase in culture supernatant and bacteria were analyzed respectively. In culture supernatant the enzyme active reaches peak after 22h, approximately 26 mU/mL. then decrease slowly. In bacteria pellet the most expression was almost 6 mU/mL after cultured 14h. While none active was detected in negative control. The results show that the promoter and signal-peptide can be used to express heterologous gene in Bacillus subtilis. The study provides considerable data which are useful for the further development of the expression vector pGPST and the study of foreign gene expression in Bacillus subtilis. The vector pGPST will play a significant role in gene expression in Bacillus subtilis.