FIG. 4.

Direct reductions of Pu(IV)(EDTA) by cell suspension of G. metallireducens (A) and S. oneidensis (B). Conditions were a cell density of 5 × 10⁸ cells/ml and a pH of 7.00. (A) Ten millimolar acetate and 0.50 mM Pu(IV)(EDTA) were used. (B) Pu(IV)(EDTA) was added in two steps. The first addition (0.5 mM) was at the point indicated by the arrow, and the second addition (1.0 mM) was at 95 min. The total Pu(IV)(EDTA) added was 1.50 mM. ▴, live cells with the electron donor; ▵, live cells with no electron donor; ▪, control with no cells; ♦, control with heat-killed cells.