A powerful cadmium resistant strain of a fungus

Author(s): Syam Sundar Konar, Abhishek Mukherjee, Md.Nazir Hossain, S.K.Mukherjee, Tapan Kumar Das

The six Cd+2 resistant strains of fungus screened by the cadmium supplementation experiment from the local sewage water of local waste water treatment center, were tentatively identified as Aspergillus niger on the basis of study of the morphology and conidial color. One of the six strains was found to showa quantitative sorption of Cd+2 bymore than 60%of the initial Cd+2 ion concentrations tested. Growth of the cadmium resistant strain was found to be maximum at 10mM and was inhibited totally in Czapex Dox (CD) broth containing 30mM Cd+2. The same strain could uptake Cd+2 intracellularly and could concentrate the same in different cellular compartments. Uptake of Cd+2 was studied at different time of incubation and also at different pH. The biosorption of high concentration of Cd+2 reflected the exceptionally high tolerance of the CdR strain to Cd+2. Removal of cadmium by the fungal strain was further substantiated by scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX), which indicated an accumulation of cadmium in the fungalmycelium.

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