FUNGAL LEACHING OF IRON ORE: ISOLATION, CHARACTERIZATION AND BIOLEACHING STUDIES OF <i>PENICILLIUM VERRUCULOSUM</i>

Abstract

Pyrometallurgical and hydrometallurgical technologies for recovery of metals from low grade ores require high energy and capital costs. Use of microorganisms in leaching of mineral ores is gaining importance due to the implementation of stricter environmental rules. Microbes convert metal compounds into their water soluble forms and are biocatalysts of leaching processes. This study was performed to isolate and characterize iron solubilizing fungi from low grade iron ore for bioleaching process. Soil samples from iron mine area were used for isolation of iron solubilizing fungi and two fungal species (NTS-1 and NTS-2) were obtained from enrichment culture method. Bioleaching experiments were carried out in batch culture to determine the iron solubilising efficiencies of the isolates. Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) was used to determine the solubilized iron concentration and strain NTS-2 exhibited 40% higher iron solubilization than strain NTS-1. The strain was subjected to 18S-ITS sequence of rRNA studies and the phylogenetic analyses justify a taxonomic position for the strain as a member of Penicillium verruculosum. The isolated strain could be used in solubilizing iron from low grade ores as an efficient, economical and eco-friendly alternative to conventional operations.