A new maltose-inducible high-performance heterologous expression system in Bacillus subtilis

Objectives To improve heterologous proteins production, we constructed a maltose-inducible expression system in Bacillus subtilis. Results An expression system based on the promoter for maltose utilization constructed in B. subtilis. Successively, to improve the performance of the PmalA-derived system, mutagenesis was employed by gradually shortening the length of PmalA promoter and altering the spacing between the predicted MalR binding site and the-35 region. Furthermore, deletion of the maltose utilization genes (malL and yvdK) improved the PmalA promoter activity. Finally, using this efficient maltose-inducible expression system, we enhanced the production of luciferase and D-aminoacylase, compared with the PhpaII system. Conclusions A maltose-inducible expression system was constructed and evaluated. It could be used for high level expression of heterologous proteins production.