Programming bacterial adhesion to functionalized surfaces through cellular display of recombinant nanobodies

The use of catalytic surfaces has an enormous biotechnological potential. Surfaces provide a material to localize and concentrate enzymes or even bacterial cells to achieve biological reactions in a more efficient way. A promising approach to specifically direct bacterial attachment to a surface of choice is the induced expression of synthetic adhesins. In this way cells are re-programmed by the adhesin to bind a specific target. Synthetic adhesins are recombinant molecules obtained by the fusion of an autotransporter module to a single-chain nanobody. In this case, the nanobody part acts as the recognition module targeting cells to cognate antigens, functioning as a perfect glue. The protocol described in this chapter aims to explain all steps required to effectively gain the functionality of the system. Specifically, the protocol provides a way to quantify and visualize bacterial immobilization on the modified surface. The methodology is exemplified by Escherichia coli with the use of two well characterized systems: (i) intimin as surface display and a (ii) nanobody that targets fibrinogen as adhesin.