FIG. 3.

The degradation of 500-μg g⁻¹ 2,4-D and the appearance of 2,4-D-degrading microbial populations with time in weeks, as detected in pilot field scale bioreactors containing Brazito soil amended with 2,4-D only (Treatment 1) (a); 2,4-D and 60 μg of cadmium g⁻¹ (Treatment 2) (b); 2,4-D and 10⁴ CFU of R. eutropha JMP134 g⁻¹ (Treatment 3) (c); 2,4-D, 60 μg of cadmium g⁻¹, and 10⁴ CFU of R. eutropha JMP134 g⁻¹ (Treatment 4) (d); 2,4-D, 60 μg of cadmium g⁻¹, 10⁴ CFU of R. eutropha JMP134 g⁻¹, and 10⁴ CFU of cadmium-resistant Pseudomonas strain H1 g⁻¹ (Treatment 7) (e). The original number of 2,4-D degraders was fewer than 10² CFU g⁻¹ of soil prior to bioaugmentation. Treatment 5 (2,4-D and Pseudomonas strain H1) and Treatment 6 (2,4-D, 60 μg of cadmium g⁻¹, and Pseudomonas strain H1) are not shown.