Abstract

SUSTAINABILITY OF ASPERGILLUS SPP. IN METAL ENRICHED SUBSTRATE AIMING TOWARDS INCREASING BIOREMEDIATION POTENTIAL

Aroni Mitra*, Deesha Roy, Poushali Roy, Anusree Martina Bor, Binayak Sarkar, Dr. Arup Kumar Mitra

ABSTRACT

The investigation focuses on the impact of Copper(II) and Zinc(II) ions on the growth, biosorption capacity and resistance mechanisms of Aspergillus spp. isolated from metallic industrial effluent. Heavy metal ions due to their high density are toxic to the living systems and hence when released into the environment cause substantial damage to the ecosystem. Bioremediation of heavy metal ions proves to be an exemplary method in reducing environmental pollution. The fungal isolate was screened for its ability to absorb heavy metal ions from nutrient medium supplemented with various concentrations of Copper(II) and Zinc(II) ions. Aspergillus spp. is adept in absorbing heavy metal ions from potato dextrose media bearing 100mg/L of Cu+2 and 750mg/L of Zn+2 ions. Addition of heavy metal ions in growth medium resulted in the substantial increase in the activities of copper-amine oxidase, Cu-Zn superoxide dismutase, catalase and peroxidase. Increased expression of copper-amine oxidase serves as an excellent indicator of intracellular reactive oxygen species (ROS) generation in fungal cultures under heavy metal stress. However the increased activities of Cu-Zn superoxide dismutase, catalase and peroxidase enable the mould to withstand the oxidative stress induced by heavy metal ions. These enzymes scavenge the ROS produced and allows Aspergillus spp. to grow past the toxic effects of Copper(II) and Zinc(II) ions. These increased enzymatic activities play a pivotal role in understanding the cellular and molecular abilities of Aspergillus spp., which can be effectively utilized in decreasing heavy metal pollution.

Keywords: Copper, Zinc, Bioremediation, Biosorption, Aspergillus spp., Reactive oxygen species.