Abstract:

The thermostable α-amylase was widely used in the fields of food industry etc., in the present study, a moderate thermostable α-amylase gene was cloned from Bacillus subtilis FS321, which was isolated from the dunghill soil in the northern of China, and expressed in Escherichia coli BL21 (DE3). The α-amylase gene from B.subtilis FS321 (BSA) was cloned using PCR method, the complete ORF of BSA was in a size of 1980 bp. The recombinant expression vector of pET-28a/BSA was constructed, and transformed to E. coli BL21 (DE3). A fusion protein with a size of about 73.0 kDa displayed in SDS-PAGE and the clear zones developed in the soluble starch plate demonstrated that the BSA was functional expressed in E. coli after induction by IPTG. The optimum reaction temperature of the recombinant α-amylase was of 50℃, and optimum reaction pH of 7.5.