Soil samples collected in sugarcane fields with a history of use of the herbicide diuron were employed to isolate and characterize bacterial strains with potential to degrade diuron. Strains were isolated from rhizosphere soil and from soil between plant rows. A total of 98 strains were isolated, of which 27 were selected for further evaluation of pesticide degradation potential at the concentrations of 5, 10 and 20 mug mL-1 in mineral agar media. Acinetobacter baumannii strain D12-12 was chosen to study the kinetics of growth in a mineral medium, with and without N, or with and without glucose (0.5%) and supplemented with diuron at either 20, 50 or 100 mug mL-1. In the first experiment, five strains presented exponential growth between 0-48 hours (D12-12, D12-14 e D16-12) or between 0-110 hours (D11-9 e D12-18). Growth of the strain D12-12 was found to vary dependly on the concentration of nitrogen, glucose and diuron.
Acinetobacter baumannii; biodegradation; herbicide; diuron; growth curve