Biosorption of Cadmium by Fungi Isolated from Bharalu River, Assam

Abstract

Heavy metal pollution in the aquatic ecosystem poses a serious threat to the human health and aquatic biodiversity around. There is urgent need to remediate heavy metals contaminated wastewater through eco-friendly ways. Fungi and other microorganisms havebeen reported to have promising potential to remove heavy metals from wastewater through biosorption. Thus,the present work aimed to isolate tolerant fun-gal species from different sites of a polluted river Bharalu in Assam. After preliminary screening, out of a total of 15 fungal isolates obtained, 4 isolates Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus,and Colletotrichum gloeosporioides were selected for further study. Tolerance limit of the isolates for Cadmium (Cd) was car-ried out at concentrations ranging from 100 ppm to 1000 ppm. Results showed that the maximum tolerance was observed in C.gloeosporioides, followed by A.flavusat 400ppm. The biosorption efficiency at 400ppm revealed that the maximum Cd con-centration was absorbed byfungal biomass of C.gloeosporioides(12.83 mg/g) and the minimum by A.niger(3.91 mg/g). Molecular identification was carried out fol-lowed by PCR amplification of the fungal biomass showing highest absorption. The sequence obtained was submitted in the GenBank using BANkIt with accession num-ber-MN714368 which showed high similarities with C. gloeosporioides.The results indicate that isolated fungi have potential to be used to remove metals from polluted water

Keywords

• bioremediation
• biosorption-tolerance limit
• heavy metals
• fungi