Environmental Effect of Native and Mutated B. subtilis And P. fluorescens On the Removal of Lead and Cadmium over Time

Abstract

This experiment was conducted in the laboratories of the Department of Soil Science and Water Resources, College of Agriculture, University of Basrah. Soil samples were collected from various areas of Basrah governorate  . This study showed the effect of inoculation with B. subtilis and P. fluorescens (both native and physically mutated) on the removal rate  of heavy metals (lead and cadmium) from the liquid nutrient medium. Native B. subtilis achieved a removal rate  of 90.80% compared to 75.51% for P. fluorescens. For P. fluorescens mutated for 60 minutes, a significant improvement in removal rate  was observed, reaching 80.47%. The study indicated that mutated bacteria enhanced their ability to remove heavy metals in the contamination at critical concentrations (100 and 3 ppm) did not show a significant impact on the removal rate . Furthermore, native B. subtilis outperformed P.fluorescens in both 2 and 4 week incubation periods in removing heavy metals. The mutated strains showed better results after two weeks compared to longer incubation period .The results support previous studies indicating that genetically mutated organisms enhance bioremediation by improving microbial activity and tolerance to heavy metals