Spore-displayed streptavidin: a live diagnostic tool in biotechnology.

Streptavidin, which is one of the most widely used proteins in biotechnological application field and is active only in tetrameric form, was surface expressed on the surface of Bacillus subtilis spore. Spore coat protein of B. subtilis, CotG, was used as an anchoring motif to display streptavidin. FACS using anti-streptavidin antibody was used for the verification of surface localization of expressed CotG-streptavidin fusion protein. FACS and dot-blot were used for the verification of biological activity of displayed streptavidin with FITC-labeled biotin.