Enhanced lindane removal from soil slurry by immobilized Streptomyces consortium

• The immobilized consortium efficiently removed lindane from concentrated slurry.
• In diluted slurry, lindane removed was slightly lower than in concentrated slurry.
• Lindane removal in abiotic control was significantly lower in diluted slurry.
• Lettuce seeds grown on bioremediated slurries presented enhanced vigour index.

The aim of this work was to assess lindane removal from soil slurry by a Streptomyces consortium immobilized in cloth sachets, at different inoculum, lindane and slurry concentrations. In concentrated slurry (soil/water ratio of 2:3), the higher lindane removal (35.3 mg Kg−1) was obtained with the medium inoculum (107 CFU g−1) and the highest lindane concentration tested, at 7 days of incubation. Although, lindane removal was also detected in abiotic controls, probably caused by pesticide adsorption to soil particles. Thus, these parameters were selected for evaluating the pesticide removal in diluted slurry (soil/water ratio of 1:4). After 14 days of incubation, 28.7 mg Kg−1 of lindane were removed. Also, a phytotoxicity assay demonstrated that seeds growing on diluted slurries bioremediated during 7 and 14 days, showed an improvement in biological parameters, compared to those growing on non-bioremediated slurries. Thus, bioremediated slurries would not have toxic effects on lettuce seeds.