Metal tolerance and biosorption potential of filamentous fungi isolated from metal contaminated agricultural soil [An article from: Bioresource Technology]

This digital document is a journal article from Bioresource Technology, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Heavy metal analysis of agricultural field soil receiving long-term (>20 years) application of municipal and industrial wastewater showed two- to five-fold accumulation of certain heavy metals as compared to untreated soil. Metal-resistant fungi isolated from wastewater-treated soil belonged to genera Aspergillus, Penicillium, Alternaria, Geotrichum, Fusarium, Rhizopus, Monilia and Trichoderma. Minimum inhibitory concentrations (MIC) for Cd, Ni, Cr, Cu, and Co were determined. The MIC ranged from 0.2 to 5mgml^-^1 for Cd, followed by Ni (0.1-4mgml^-^1), Cr (0.3-7mgml^-^1), Cu (0.6-9mgml^-^1) and for Co (0.1-5mgml^-^1) depending on the isolate. Aspergillus and Rhizopus isolates were tested for their metal biosorption potential for Cr and Cd in vitro. Biosorption experiments were conducted with initial metal concentrations of 2, 4, 6 and 8mM with a contact time of 4h and wet fungal biomass (1-5g) at 25^oC. Maximum biosorption of Cr and Cd ions was found at 6 mM initial metal concentration. Aspergillus sp.1 accumulated 1.20mg of Cr and 2.72mg of Cd per gram of biomass. Accumulation of these two metals by very tolerant Aspergillus sp.2 isolate was at par with relatively less tolerant Aspergillus sp.1 isolate. Rhizopus sp. accumulated 4.33mg of Cr and 2.72mg of Cd per g of biomass. The findings indicated promising biosorption of cadmium and chromium by the Rhizopus and Aspergillus spp. from aqueous solution. There is little, if any, correlation between metal tolerance and biosorption properties of the test fungi.