Surface Display of Recombinant Proteins on<i>Bacillus subtilis</i>Spores

TLDR

The authors developed a novel surface display system using Bacillus subtilis spores to present heterologous proteins. They fused the C‑terminal fragment of tetanus toxin to the spore coat protein CotB and verified surface display by Western blot, dot blot, and flow cytometry. The system displayed over 1,500 TTFC molecules per spore, was readily detected by antibodies, and offers a simple, stable, and safe platform for surface expression of bioactive molecules.

Abstract

ABSTRACT We developed a novel surface display system based on the use of bacterial spores. A protein of the Bacillus subtilis spore coat, CotB, was found to be located on the spore surface and used as fusion partner to express the 459-amino-acid C-terminal fragment of the tetanus toxin (TTFC). Western, dot blot and fluorescent-activated cell sorting analyses were used to monitor TTFC surface expression on purified spores. We estimated that more than 1.5 × 10 3 TTFC molecules were exposed on the surface of each spore and recognized by TTFC-specific antibodies. The efficient surface presentation of the heterologous protein, together with the simple purification procedure and the high stability and safety record of B. subtilis spores, makes this spore-based display system a potentially powerful approach for surface expression of bioactive molecules.