Construction of a novel cell-surface display system for heterologous gene expression in Escherichia coli by using an outer membrane protein of Zymomonas mobilis as anchor motif

A novel bacterial cell-surface display system was developed in Escherichia coli using omp1, a hypothetical outer membrane protein of Zymomonas mobilis. By using this system, we successfully expressed β-amylase gene of sweet potato in E. coli. The display of enzyme on the membrane surface was also confirmed. The recombinant β-amylase showed to significantly increase hydrolytic activity toward soluble starch. Our results provide a basis for constructing an engineered Z. mobilis strain directly fermenting raw starch to produce ethanol.