Comparative Analyses on Heavy Metals Immobilisation Ability of Aspergillus niger, Penicillium and Trichoderma Fungi in Soil

Abstract

The heavy metals immobilisation ability of Aspergillus niger, Trichoderma, and Penicillium fungi was assessed by analysing leaching of selected heavy metals in soil. This was done by amendment of soil obtained from an irrigation site in Kaita, Katsina State with 10 mg/L of Cadmium (Cd), Chromium (Cr), Manganese (Mn), Nickel (Ni), Lead (Pb), and Zinc (Zn). This was then divided into four equal parts: one as control, and the other three with 10 ml of 4.0×10⁶ CFU/ml Aspergillus niger (An), Penicillium (Pn), and Trichoderma (Tr) added separately in polythene bags. The setup stood for 14 days, with water added every 3 days. Samples were collected on days 7 and 14, and leaching was analysed using AAS. Results showed a sharp decrease in metal concentrations by day 7, with further reductions by day 14. However, variation was observed - some fungi-treated samples had higher or lower concentrations than controls, indicating differences in immobilisation. Notably, An showed strong retention for Mn, Cr, Pb (week 1), and Cd, Zn, Ni (week 2); Tr performed best for Cd, Zn, Ni (week 1) and Pb (week 2); Pn was more effective in week 2. All fungi showed potential for soil bioremediation.