Bioaccumulation and biosorption of Co²⁺ by Neurospora crassa

Summary

Mycelial biomass of wild type and a Co²⁺-resistant N.crassa (cor) was used to remove Co²⁺ from aqueous media. Mycelia obtained from growth in nitrate N-medium (NaNO₃) was more effective than ammonium N-medium (NH₄NO₃), in removing Co²⁺. Co²⁺-resistant N.crassa cor was more efficient than wild type in removing Co²⁺ from medium containing higher concentrations (500 mg/L). Metal removal was linear up to 12 h at which 35–60% Co²⁺ is depleted from medium, reaching near saturation by 24 h (90% removal). Co²⁺ removal was as efficient even from pure solutions and sodium azide inhibited the process up to 60%. Cell walls prepared from nitrate N-medium grown mycelia bound 3–5 fold more Co²⁺ when compared to ammonium N-medium. The importance of bioaccumulation and biosorption in bioremediating toxic metal ions from effluents is discussed.