Heavy metals biosorption by mushrooms

The use of absorbents of biological origin has emerged in the last decade as one of the most promising alternatives for the control of environmental pollution caused by heavy metals. A number of methods, viz. chemical precipitation, evaporation, electroplating, ion exchange, membrane, processes, etc. exist for the removal of heavy metals from liquid wastes. All these methods are expensive and have shortcomings such as incomplete removal of metals, limited tolerance to pH change, moderate or no metal selectivity, production of toxic sludge or other products that also need disposal. Fruiting bodies of macrofungi (mushrooms) may be considered ideal for the purpose of biosorption of heavy metals because their potentiality for heavy metal uptake have already been proved. Biosorption can become a good weapon in the fight against toxic metals threatening the environment. In the present article, selective uptake of heavy metal ions by wild and cultivated mushrooms, factors influencing heavy metal uptake and effects of heavy metal uptake on growth and productivity of mushrooms have been discussed as an important aspects of heavy metal management strategies.