Preliminary evaluation of microbially mediated precipitation of Cadmium, Chromium, and Nickel by rhizosphere consortium

Elevated heavy metal soils and water contamination have been shown to impose toxic effects on plants, animals, and human health. The extent of toxicity depends on the nature of the metals, soil and aquatic system characteristics, and the complex interactions between metals and the environment. Recent studies have shown that metal-microbe interactions may be effective for the remediation of contaminated media. This study investigated the effectiveness of an isolated rhizosphere bacterial consortium for treating an aqueous solution containing 600 mg/L of Cd, Cr, and Ni. The consortium was resistant to the metal toxicity as evidenced by an increase of population density of more than 6 x [10.sup.11] cfu/mL. The microbial activity facilitated a reduction in aqueous metal concentration with a metal precipitation selectivity of Cr [much greater than] Cd > Ni. CE Database keywords: Heavy metals; Water pollution; Soil pollution.