Biosorption of aluminum, cobalt, and copper ions by Providencia rettgeri isolated from wastewater

Twenty-three bacterial isolates from polluted water and soil were screened for heavy metals resistance (i.e., Al3+, Co2+, and Cu2+). The most potent isolate was identified by morphological characteristics, biochemical tests and confirmed by API20E kits as Providencia rettgeri MAM-4. Removal of Al3+ from aqueous solution by P. rettgeri is more efficient (approximate to fourfold) than that by B. cereus ATCC 11778 (a comparison strain) at concentration of 200mgL-1 Al3+. P. rettgeri was able to remove Co2+ more than B. cereus ATCC 11778 at concentration of 50mgL-1 Co2+. Inoculation of P. rettgeri into clay enhanced significantly the removal of Al3+, Co2+, and Cu2+. P. rettegri MI (mutant strain) was able to tolerate more Al3+ than that of the parent strain. P. rettgeri was resistant to 7 out of 15 antibiotics tested. P. rettgeri MAM-4 isolated from wastewater had ability to remove Al3+, Co2+, and Cu2+ efficiently from aqueous media; and enhanced significantly metal biosporption by clay. This study has revealed that P. rettgeri could be employed as an effective and economic technology for the removal such metal elements from polluted environment.