Using the Escherichia coli OmpC protein as an anchoring motif, four different poly-His units (1, 2, 3 and 6 copies of 6-His) were displayed on the seventh loop of the OmpC. Recombinant E. coli strains displaying 1, 3 or 6 copies of poly-His became much more sensitive to SDS (0.1%, w/v) and EDTA (2 mM) compared with control strains. However, recombinant E. coli cells displaying 2 copies of poly-His were resistant to SDS and EDTA; greater than 70% and 90% of cells maintained cell integrity after 60 min treatment with SDS and EDTA, respectively, suggesting its usefulness as a whole cell biosorbent.