Inducer-free over expression oe beta-galactosidase in bacillus subtilis by using promoter PGRAC57

Abstract

A thermostable (β-galactosidase (BgaB) from Bacillus stearothermophilus is a potential candidate to be exploited in the dairv industry thank to its performance of high-level hydrolysis of lactose at high temperature. Production of BgaB in a mesophilic host using recombinant protein techniques is an effective method in the industrial scale. Bacillus subtilis is an ideal host cell factory for its well-known advantages. Inducer-free pHT plasmids based on Pgrac 01 and Pgrac 100 were previously reported to express reporter proteins at high levels in the absence of inducers.