Preliminary bioleaching of heavy metals from contaminated soil employing indigenous Penicillium Chrysogenum strain F1

Bioleaching is an environment-friendly and economical technique to remove heavy metals from contaminated soil. The objective of this work is to find out an indigenous strain to remedy soil contaminated by Zn, Pb, Cu and Cd. A strain which was selected from the soil of a local smelting industry was found to be able to produce many organic acids and degrade pH value of the liquid medium. The fungus strain is identified as Penicillium Chrysogenum (P. Chrysogenum) by sequencing 18srDNA and ITS. Bioleaching condition using P. Chrysogenum is optimized. Glucose is the best carbon source for P. Chrysogenum and inorganic nitrogen is better than organic nitrogen. In addition, neutral solution and room temperature are fit for P. Chrysogenum to bioleach. In the one-step bioleaching, the bioleaching ratios are 39.95% for Zn, 9.4% for Pb, 34.89% for Cu and 49.59% for Cd, which are 53.89% for Zn, 14.44% for Pb, 55.53% for Cu and 62.81% for Cd in the two-step bioleaching. The efficiency of two-step bioleaching is better than the one-step bioleaching. P. Chrysogenum is effective in removing heavy metals from the contaminated soil.