| Uncontrolled discharge of industrial waste water into natural water resources, hospital waste drainage and other anthropogenic activities release tremendous amounts of heavy metals in the environment, especially in water bodies. The accumulation of these toxic metals in the food chain causing health hazards to all aquatic and terrestrial animals is of greater concern these days. This study was conducted to find an effective and safe bioremediation tool for heavy metal pollution using naturally occurring bacteria. Four bacterial isolates were identified from the soil of Marquez Crater, a meteorite impact area. The isolates were inoculated into media containing increasing concentrations of iron, copper, nickel and zinc to determine the maximum tolerance for each heavy metal. All isolates showed low maximum tolerance for zinc (20, 10, 10 and 10 mg/L) and nickel (20, 10, 20 and 20 mg/L) when compared to iron (100, 50, 50 and 50 mg/L), and copper (75, 20, 50 and 40 mg/L). Optimum temperatures and pH for each isolate varied from 25 to 37°C and from 7 to 9 respectively. The order of removal efficiency for heavy metals was Fe>Zn>Cu>Ni. Isolate I-2 was particularly effective in removing 91.69% of iron. Results showed the potential of isolates to be effective in removing toxic metals from sewage, drainage, industrial effluents, and other polluted water sources to grow in a range of temperature. |
