Bacterial whole-cell biocatalysts by surface display of enzymes: toward industrial application

Going beyond E. coli: autotransporter based surface display on alternative host organisms

Autotransporters represent one of the most popular anchoring motifs used to display peptides, proteins or enzymes on the cell surface of a Gram-negative bacterium. Applications range from vaccine delivery to library screenings to biocatalysis and bioremediation. Although the underlying secretion mechanism is supposed to be available in most, if not all, Gram-negative bacteria, autotransporters have to date almost exclusively been used for surface display on Escherichia coli. However, for their utilisation beyond a laboratory scale, in particular for biocatalysis, host bacteria with specific features and industrial applicability are required. A few groups have addressed this issue and demonstrated that bacteria other than E. coli can also be used for autotransporter based surface display. We summarise these studies and discuss opportunities and challenges that arise from surface display of recombinant proteins using the autotransporter pathway in alternative hosts.