New Bacterial Surface Display System Development and Application Based on Bacillus subtilis YuaB Biofilm Component as...

Bacterial surface display system has been adopted in various biotechnological applications. In the case of Bacillus subtilis, most of the studies have been developed using spore based surface display system utilizing the inherent rigidity of spore against heat, alkali, and shear stress. But, spore harvest, purification and separation need additional cost and labor. To eliminate this procedure and to use the gram-positive nature of B. subtilis, YuaB, which is one of the major B. subtilis biofilm components and locates in the cell wall, based cell surface display system, is developed. P43 promoter driven overexpression of YuaB-His₆ tag does not hamper bacterial cell growth and promoted biofilm formation of recombinant strain. Flow cytometry of recombinant strain and its protoplast using FITC-Anti His₆ antibody, verified that YuaB locate in plasma membrane and protrude to the outside of cell wall, which means YuaB can be used as very efficient anchoring motif. Using surface expressed YuaB-His₆ tag, removal of divalent metal ion, Cu²⁺ and Ni²⁺, was tried to test its possibility for the environmental application of developed system.