5. Mechanism of metal uptake
The understanding of the mechanism by which microorganisms
accumulate metals is crucial to the development of
microbial processes for concentration, removal and recovery
of metals from aqueous solution. Metabolism-independent
metal binding to the cell walls and external surfaces is
the only mechanism present in the case of non-living biomass.
Metabolism-independent uptake essentially involves
adsorption process such as ionic, chemical and physical
adsorption. A variety of ligands located on the fungal walls
are known to be involved in metal chelation. These include
carboxyl, amine, hydroxyl, phosphate and sulfhydryl