Fungal Biosorption Strategies for Heavy Metal Removal

Biosorption, driven by passive binding of heavy metal ions to fungal cell walls, has garnered attention as a cost-effective and environmentally benign method to remediate contaminated waters and soils globally. Fungal biosorbents leverage an array of functional groups within polysaccharides, proteins and lipids that confer specificity and high affinity for diverse metals, including chromium, cadmium, copper, lead and uranium. Both live and dead fungal biomass have been explored: living cells may facilitate active uptake and intracellular sequestration, whereas non-living biomass offers enhanced stability and tolerance to high metal concentrations. Advances in isotherm modelling and kinetic analyses have clarified the influence of pH, temperature, contact time and biomass dosage on adsorption capacity, enabling optimisation of batch systems and design of continuous-flow bioreactors. Pelleted formations of filamentous fungi further improve handling and recovery of biomass, while selective genetic and adaptive strategies in strains such as Aspergillus, Penicillium and Trichoderma species have raised uptake capacities above 100 mg g–1. Integrated studies now demonstrate not only efficient metal removal in synthetic and real wastewaters but also the simultaneous transformation of toxic species, such as the reduction of hexavalent chromium to less harmful trivalent forms. These developments underscore the potential of fungal biosorption as a scalable tool for industrial effluent treatment, mining runoff management and water recycling in a circular economy framework.

Research from Nature Portfolio

One foundational study has characterised the mechanics of chromium uptake by the heat-dried biomass of a novel fungus, revealing a multifaceted adsorption process encompassing physisorption, chemisorption, oxidation–reduction and chelation. Kinetic data fitted to a pseudo-second-order model, while equilibrium was best described by a Redlich–Peterson isotherm, predicting maximum capacities near 100 mg g–1. Surface analyses, including XPS and FT-IR, confirmed substantial reduction of hexavalent chromium to trivalent species and identified key binding moieties within the fungal matrix. The work also demonstrated effective depletion of chromium from industrial effluents, thereby illustrating both mechanistic insights and practical applicability.

Fungal Biosorption Strategies for Heavy Metal Removal publication trend

The graph below shows the total number of articles in fungal biosorption strategies for heavy metal removal across all publications each year (not limited to Nature Index journals).

Technical terms

Biosorption: Passive binding of metal ions onto functional groups of biomass without metabolic energy. Bioaccumulation: Active uptake and intracellular sequestration of pollutants by living organisms. Isotherm modelling: Mathematical description of adsorption equilibrium relating solute concentration in solution to that on the sorbent surface. Mycelium: Network of fungal filaments forming the vegetative body, rich in adsorption sites. Chelation: Formation of stable complexes between metal ions and multidentate ligands on biomass surfaces.

References

1. Application of the novel Cu-resistant fungus Aspergillus niger A3 in bioremoval of Cu-NPs from its aqueous solutions. OpenNano (2023).
2. Removal of heavy metals from aqueous media by biosorption. Journal of the Association of Arab Universities for Basic and Applied Sciences (2020).
3. Biosorption of Water Pollutants by Fungal Pellets. Water (2020).
4. Comparative Utilization of Dead and Live Fungal Biomass for the Removal of Heavy Metal: A Concise Review. The Scientific World JOURNAL (2021).
5. Recent Advances in Biosorption of Copper and Cobalt by Filamentous Fungi. Frontiers in Microbiology (2020).
6. Depletion of Cr(VI) from aqueous solution by heat dried biomass of a newly isolated fungus Arthrinium malaysianum: A mechanistic approach. Scientific Reports (2017).