Ni2+ was removed quantitatively, from aqueous solution into a microbially-created crystalline deposit of hydrogen uranyl phosphate (HUP). The mechanism of Ni2+ removal is an ion-exchange intercalation of Ni2+ into the interlayer space of HUP. The Ni2+-removing capacity of a column was proportional to the mass of HUP deposited and the Ni/HUP-loaded column was regenerated by washing with uranyl solution containing citrate/MOPS buffer and glycerol-2-phosphate, or with citrate buffer alone. Regeneration in the presence of UO22+ increased the Ni2+-removing capacity of the column. A new mechanism for the removal of heavy metals via microbially enhanced chemisorption is proposed.