B. subtilis, being a gram-positive endospore forming bacteria, is the most desirable and favorable choice for cell surface display with spore coat protein as anchoring proteins, including CotB, CotC, CotE, CotG, CotX, CotY, CotZ, CgeA, and OxdD. For successful spore surface display, it is significant to select an appropriate anchor protein because it contains efficient signal peptide or transporting signal for efficient promotion of transportation, immobilization and stability. B. subtilis spore surface display, a well-established technology for protein analysis and engineering, involves expressing exogenous proteins as a genetic fusion to either the N- or C-terminus of anchoring proteins.

A suitable anchoring protein needs to meet the following requirements:

• They must have a strong anchoring domain to ensure that exogenous proteins can be immobilized on the spore surface.
• They must be compatible with foreign proteins, be able to form fusion proteins, and should not be able to interact with each other.
• They must be resistant to protease hydrolysis.

Hence, spore surface display is the most desirable and the most promising technology which provides feasible avenues to improve industrial production efficiency. Kwon et al. (2007) developed a new kind of whole-cell biocatalyst which display β-galactosidase on B.subtilis spore by fusion it to the spore CotG protein.

Creative Biogene develops the recombinant approach which is based on the modification of B. subtilis genome to display a passenger protein of interest as a fusion with spore coat protein. At present, we select the non-essential genes amyE, lacA and pyrD as insertion sites to creating a multi-anchoring protein display system. With the rich experience, our talented scientists advise appropriate construction strategy in various biotechnological applications. Please feel free to contact us if you have any concerns.