Direct reductions of Pu(OH)4(am) by cell suspension of G. metallireducens (A) and S. oneidensis (B) with 0.5 mM EDTA. Conditions were a cell density of 5 × 108 cells/ml, a pH of 7.00, an acetate concentration of 10 mM (A) or a lactate concentration of 10 mM (B), and a Pu(OH)4(am) concentration of 0.50 mM. ▴, live cells with the electron donor; ▵, live cells with no electron donor; ▪, control with no cells; ♦, control with heat-killed cells.