2) Bacillus subtilis Secretion System

Another expression & secretion system is engineered in B. subtilis for efficient extracellular production of heterologous proteins. Regulatory cassettes containing transcriptional controls derived from the veg I promoter and the Staphylococcal protein A signal peptide are employed in this system.

There are many advantages of the extracellular approach over the intracellular one for the production of recombinant proteins.

• - Correct folding to a functional native form – authentic and bioactive product

• - Reduction of proteolysis, and thus higher product yields

• - Reduction of contamination from unwanted proteins (e.g. endotoxin), and thus attainment of product with better quality

• - Unwanted N-terminal methionine can be avoided

• - Easy purification process and reduced production cost

• - Suitable for large and industrial scale production

• - Applicable for the production of all naturally secretory proteins

• - Applicable for the production of mildly toxic proteins

• - Continuous production possible