European Journal of Biomedical and Pharmaceutical Sciences

BIOTRANSFORMATION OF INSOLUBLE LEAD COMPOUND INTO THE NON-TOXIC FORM BY SOIL FUNGUS

G. Vathsala Devi, A. Manivel, M. Saravana Kumar and S. Chandra Mohan*

ABSTRACT

Nowadays, due to industrialization and extraction of natural resources, soil and water pollution is one of the major global concerns. During the recent era of environmental protection, the use of microorganisms for the recovery of heavy metals from soil, sediments and water as well as employment of plants for landfill applications has generated growing attention. The role of microorganisms and plants in biotransformation of heavy metals into nontoxic forms is well-documented in this work. The objective of this research was to investigate the ability of fungi to solubilise and immobilize insoluble lead carbonate (PbCO3). Soil fungi were isolated from contaminated soil in Mathur Industrial Estate, Trichy, Tamil nadu. The isolated fungus was plated on PDA medium supplemented with 0.5% (w/v) of insoluble lead carbonate. Aspergillus niger showed the highest activity in solubilising insoluble lead carbonate with clear zone appearance more than 40 mm. in diameters. Precipitation of lead biomineral crystals was observed in agar medium underneath colonies of A. niger. The crystals were purified, and analyzed by scanning electron microscope (SEM), mass spectrum and X-ray powder diffraction (XRPD), and the results revealed that they were lead oxalate (PbC2O4). Biotransformation by microbes could be efficient method to reduce the lead contaminants of soil. It is suggested that soil fungus have potential application in heavy metal biotransformation.

Keywords: Biotransformation, soil fungus, lead oxalate, XRD.