The development of a microbial metal - resistance consortium for metal bioremediation in a simulated fluvial system

Abstract

Our main goal was to enrich the microbial population which develops when a pollution event changes the
equilibrium of a fluvial system and thereafter investigate the effectiveness of this adapted bacterial consortium in
a simulated bio-remediation process. The contaminated soil of a highly heavy metal polluted mining deposit was
mixed with non-contaminated fluvial sediment in a ratio of 1:3. After the addition of fresh fluvial water, the
system was allowed to equilibrate for one month. Then, a research was carried out on experimental microcosms
in order to test the effects of the surviving microorganisms on toxic heavy metals (Cu, Fe, Zn) that are polluting
surface sediments. The adapted microbial population was first enriched in aerobic conditions with a high
concentration of heavy metals (up to 300 mg/l Cu; 400 mg/l Fe; 600 mg/l Zn) and afterwards the consortium
obtained was applied in a microcosm to test its effect on the decontamination of heavy metals. The study has
demonstrated that some microorganisms can survive the contamination. However, with regard to the tested
metals, the microorganisms did not influence the status of the metals during the period of the analysis.