Bioremeoval of hexavalent chromium, using Pseudomonas Fluorescens

Rapid urbanization and Industrialization without proper environmental planning lead to the discharge of toxic heavy metals in the environtment. The toxic heavy metals entering into the ecosystem may lead to geo accumulation, bioaccumulation and biomagnification. Removal of heavy metals from wastewater needs advance chemical technology and is more expensive too. The cheaper alternative for this is the bioremediation using heavy metal resistant Microorganisms. Hence in the present study an attempt has been made to study the biosorption of chromium ions by Pseudomonas fluorescens. Experiments were also designed to study the effect of dead cells and sugars on the biosorption of hexavalent chromium ions. Pseudomonas fluorescens were exposed to different concentration of hexavalent chromium (200, 400, 600 and 800 ppm) for a period of eight days. Atomic absorption spectroscopy (AAS) analysis was carried out for the samples at an interval of two days. The highest hexavalent chromium uptake was found to be at 800 ppm concentration. Metal binding by bacteria has been shown to be profoundly influenced by the concentration of the metal. The mechanisms have not been examined thoroughly, but it is clear that the bacterial cells may act as nucleation sites for the removal of metals from the environment. Thus these findings suggest the possibility of using these bacterial isolate for bioremediation of hexavalent chromium from heavy metal contaminated ecosystems. Key words: Hexavalent chromium; Pseudomonas fluorescens; bioremediation; Atomic absorption spectroscopy.