부산대학교 도서관

Cadmium and zinc appear in the combined forms and they are co-pollutants. Cd is the most hazardous metal ion for human beings and causes renal dysfunction, liver and lungs damage, bone degeneration and blood damage. Though Zn is an essential nutrient, excess of Zn is toxic. Biological process was more important because conventional methods fail to remediate these pollutants due to high costs and less affordability. The screening and understanding of the functioning of microorganism plays an important role in removal and recovery of metals from heavy-metal-polluted water and soil. In our study, the strain Pseudomonas aeruginosa BC15 was isolated from oil-mill-treated waste water and it showed to be highly resistant to 6 mM Cd and 20 mM Zn in the solid and liquid media. The growth studies of BC15 strain in the medium without induction exhibited high tolerable capacity when compared to other microbes. Pretreatment of P. aeruginosa BC15 with sub-lethal concentrations of Cd induced adaptive resistance to lethal doses of Cd. Cadmium-induced cells also showed cross resistance to lethal concentration of zinc. The organism had high resistance against Cd and Zn. This has been clearly proven through biosorption studies: Cd was absorbed up to 62% and Zn about 60% in single solution, whereas in binary solution Cd was biosorbed up to 82% and Zn 85%. In conclusion, this study reveals the significance of using the strain P. aeruginosa BC15 in the bioremediation of Cd and Zn from industrial waste water and contaminated soil.