SOME IMPORTANT FUNGI, TRICHOPHYTON SP., BEAVERIA BASSIANA AND PLUROTUS OSTREATUS RESIST HEAVY METALS: PROMISING FUNGAL STRAINS FOR THEIR POTENTIAL AS BIOREMEDIATION AGENTS

Many industries like electroplating, paint, lather tanning etc. release enormous amount of heavy metals contaminated wastewater. These heavy metals enter into human beings and animals through food chain. So there is a need to remove these heavy metals through low cost technology. Microorganisms including fungi and bacteria have been reported to exclude heavy metals from wastewater through bioaccumulation and biosorption at low cost and in an eco-friendly manner. An attempt was, therefore, made to screen various fungi such as Trichophyton sp., Beaveria bassiana and Pleurotus ostreatus on Potato Dextrose Agar (pH 5.0) supplemented with 20, 40, 60, 100 and 500 mg/l concentrations of Cd, Fe, Ni and Hg individually. Observations on growth of fungi were made after 5 days of incubation at 28±20C. The results showed that all the fungi showed a dose dependent decrease in growth pattern with the increase in metal concentration. Trichophyton sp. and Pleurotus ostreatus were found to resist Cd, Ni and Fe more effectively than B. bassiana. However none of the strains could grow above 100 ppm concentrations of all the heavy metals. Hgcontaining plates though, didn't show any growth even beyond 40 ppm which indicates the toxicity level of mercury in the all fungal strains and their inability to tolerate this metal above the said concentration. These fungal strains could be potentially very useful in bioremediation in terms of removal of toxic heavy metals.