Biosorption of heavy metal arsenic from Industrial Sewage of Davangere District, Karnataka, India, using indigenous fungal isolates

Abstract

Contamination of soil and water bodies with heavy metals like arsenic (As) is of major concern, since arsenic is non-biodegradable, toxic and causes ill effects to gastrointestinal system, skin, liver, kidney or neurological functions. In addition, animals affected by arsenic pollution through fodder intern enter to food chain. Hence, there is an urgent need to address heavy metal arsenic pollution especially through bioremediation. In this context, biosorption with indigenous microbiota has gained more interest in recent years as it is cost-effective, eco-friendly approach and with no adverse effects. In the present study, arsenic (As III)-resistant strains of fungi were isolated from soil samples collected from various locations of industrial sewage disposal sites of Davangere District, India, and screened. Among five fungal isolates, Aspergillus spp APR-1 and APR-2 showed greater resistance to arsenic in the laboratory conditions. In order to increase the surface area for biosorption, APR-1 and APR-2 isolates were immobilized on Luffa aegyptiaca (sponge gourd) (an agro-waste as biosorbent). With 250 mM arsenic solution, Aspergillus spp APR-1 and APR-2 showed biosorption of 53.94 and 52.54%, respectively, on inductively coupled plasma-optical emission spectrometry analysis and the adsorption of the fungal isolates on sponge gourd was confirmed using scanning electron microscopy. APR-1 isolate was further characterized by 18 s rDNA typing and identified as Aspergillus niger. Industrial scale application perhaps is taken up using selected fungal strains and mitigates the arsenic pollution in urban sewage.