Bioremediation of Heavy Metal Using Consortia Developed from Municipal Wastewater Isolates

Abstract

Nowadays heavy-metal pollution has become an environmental problem due to their toxic effects, and their invasion in to the food chain leads to serious environmental and health problems. Heavy Metal degradation through common physico-chemical techniques is very expensive and unsuitable in treating large contaminated area effectively. Bioremediation provides a promising means to reclaim such toxic substances in an economical and ecofriendly way. Bioremediation obtains microorganisms that capable to degrade toxic contaminants or have the ability to accumulate it in their cells. The present study was carried out to evaluate degradation capacity of consortia developed from municipal wastewater isolates. The activity of the isolates for hemolysis was studied on the Blood-Agar plates. The identification of isolates obtained through biochemical and morphological characteristics. Seven isolates and three defined consortia were tested for degradation of heavy metals (zinc, lead and chromium). Consortia 3 (R9 + S11 + T12) showed better degradation with 93.78% ability in reducing zinc when incubated for 72 hours and 86.16% when incubated for 24 hours. The lead reduction was found to be 84.33% by Consortia 1(A3 + B4) when incubated at 37°C for 72 hours incubation. The chromium was reduced by Consortia 2(C6 + D7) with 87.61% ability when incubated for 72 hours. The organisms had capacity to reduce the heavy metals depending on the factors like time and concentration of inoculum. As the time of incubation increases, more reduction was observed. This study gives us insight in to the inherent potential of the Consortia to bio remediate toxic heavy metals.