TOLERANCE AND BIODERADATION CAPACITY OF Trichoderma viride WITH SPECIAL REFERENCE TO HEAVY METALS (Cr, Cd)

Heavy-metal pollution represents an important environmental problem due to the toxic effects of metals, and their invasion in to the food chain leads to serious ecological and health problems. Metal remediation through common physico-chemical techniques is expensive and unsuitable in treating large contaminated area effectively. Bioremediation offers a promising means to reclaim such contaminated soil in an economical and eco friendly way. Bioremediation employs microorganisms capable of degrading toxic contaminants or have the ability to accumulate it in their cells. This concentrated end product can afterwards be directed for a controlled way for recovery of metals. In this study Trichoderma viride was used for the removal of heavy metals like Chromium and Cadmium from contaminated soil .The tolerance of Trichoderma viride against the metals was found to be up to 200 ppm and for Cr, 200 ppm for Cd 2+. The parameters affecting the biosorption of heavy metals; such as metal concentration and biomass concentrations have been investigated. The results revealed that tolerance of about 67-82% of Cr and 73-79 % of Cd 2+ was attained at 200ppm concentration. Bioabsorption rate are higher when the cells are in stationary phase. The bioabsorption and the growth of the microorganism in aerated soil were found to be more comparing to non-aerated soil.