Construction of plasmid-based expression vector for Bacillus subtilis

Plasmids are useful tools to study gene expression and their function. However, most of the available plasmids for Bacillus subtilis suffer from structural instability because of their rolling-circle replication mechanism. In this work, stable plasmids have been constructed allowing expression of recombinant proteins in the cytoplasm and their secretion into the culture supernatant. The author has also established an experimental system to immobilize proteins on the cell wall of B. subtilis. The sorting of surface proteins to the cell wall in B. subtilis has been investigated aiming to anchor recombinant protein on the surface.