In the present study,effects of different host strains of Bacillus licheniformis on the expression and secretion of α-amylase were investigated.Firstly,the α-amylase expression vector,named pP43 SAT,was constructed based on the promoter P43 from Bacillus subtilis and the signal peptide,coding region and terminator of α-amylase gene from B.licheniformis WX-02.The pP43 SAT plasmids were then transformed into the B.licheniformis host strains WX-02(Δ amyL),BL9 and BL10 B,respectively,to obtain the α-amylase gen...