Bioaugmentation assisted mycoremediation of heavy metal and/metalloid landfill contaminated soil using consortia of filamentous fungi

Abstract

This research aimed to demonstrate the significance of bioaugmentation in the mycoremediation of metals and metalloid (Cr, Cu, As, Fe, Mn) polluted landfill soil using consortia of autochthonous filamentous fungi. The fungal consortia used were Ascomycota, all isolated fungi, and Basidiomycota. Bioremediation was monitored for pH, redox potential, electrical conductivity, residual heavy metal/metalloid content, fungal population and enzyme activity at day 0 (initial day), day 20, day 60 and day 100. Results have shown a decreasing trend for all the monitored physicochemical parameters. Fungal organisms have a maximum tolerance index of 1.0 on Fe, Cu and Cr supplemented Agar medium. Highest colony count of 1.17 × 1010 CFU/g soil was recorded in Basidiomycota treated soil. On the other hand, a consortium of all isolated fungi proved efficient in the removal of As(77 %), Mn(71 %), Cr(60 %), and Cu(52 %). Meanwhile, Fe removal of 56 % was prioritized by the Ascomycota consortium. Acid phosphatase had the weakest activity (0.03 – 0.72 μmol PNPg−1 dry soil h−1) for all the treatments. FTIR results have shown the appearance of absorption peaks at 1485 - 1445 cm−1 only in soil amended with fungal consortia. Fungi bioaugmented soil had the maximum metal bio removal efficiency than the untreated control soil (P < 0.05).