LEAD AND CADMIUM DETOXIFICATION BY HALOPHILIC BACTERIA ISOLATED FROM SOLAR SALTERNS IN LEBANON

Water contamination by heavy metals has gained considerable attention globally. These inorganic pollutants can enter the aquatic environments via different routes thereby threatening biodiversity and human health. Lead and cadmium are hazardous pollutants where their removal by traditional techniques is identified to be costly and ineffective. However, bioremediation by extremophilic microorganisms is considered to be a promising technique as they have considerable potentials to grow in harsh environmental conditions. The present study deals with the isolation of halophilic bacterial isolates from solar salterns in North Lebanon. The isolate H1S9 was identified as Halomonas venusta H9 after showing tolerance to 500 mg L-1 of lead and cadmium. Conductivity and Fourier Transform Infrared spectroscopy showed that Pb2+ and Cd2+ were removed by Halomonas venusta H9. Transmission Electron Microscopy demonstrated the ability of Halomonas venusta H9 biomass to bioaccumulate Pb2+ and Cd2+ from aqueous solution into the cells. The factors affecting the bioaccumulation process were investigated