In-vitro remediation of arsenic by fungi

Heavy metal pollution is one of the major issues the world is facing today. These heavy metals are highly poisonous even in low concentration and contaminate environment due to their ability of geo-accumulation, biomagnification and bioaccumulation. Heavy metal arsenic (As) is also a threatening environmental pollutant, its inorganic forms arsenite and arsenate are lethal and shows chronic health risks to human. Myco-remediation is a natural process in which fungi breakdown such toxic metal pollutants to a less toxic state by complete mineralisation in the environment. In this paper, we have studied the In-vitro toxic effect of different doses (0 ppm, 1 ppm, 5 ppm and 10 ppm) of As on growth of fungi namely Aspergillus niger, Trichoderma harzianum, Beauveria bassiana, Metarhizium anisopliae and biosorption potential of fungi for As up to incubation period of five days (120 hours). Results showed that the radial growth rate of fungi decreased with increase in dose of As from 0 ppm to 10 ppm as A. niger 0.65-0.48 mm h⁻¹, T. harzianum 0.73-0.41 mm h⁻¹, B. bassiana 0.60-0.16 mm h⁻¹ and M. anisopliae 0.40-0.13 mm h⁻¹. The mean biosorption of fungi was A. niger 0.09 mg g⁻¹, T. harzianum 0.16 mg g⁻¹, B. bassiana 0.04 mg g⁻¹ and M. anisopliae 0.04 mg g⁻¹. The data obtained from present study revealed that T. harzianum was the least affected fungus by As toxicity and showed the highest mean biosorption therefore it can be considered a good agent for the in-vitro remediation of As up to 10 ppm concentration.