ABSTRACT
This chapter addresses two aspects of metals biotechnology: the opportunities for novel biological processes for removing heavy metals from industrial effluents; and the traditional biological processes for extracting metals from ores. Biological systems for industrial metal recovery applications need to demonstrate distinct advantages over existing processes, for example: Organisms currently used for the industrial production of biochemicals such as enzymes and antibiotics provide a potential source of cheap, available biomass for metal recovery. The biological uptake of soluble metals is described as adsorption, complexation or binding. Adsorption may be defined as the concentration of a substance at a surface and does not necessarily imply physical binding. Microbial biomass possesses a large number of chemical sites at which metals may be bound. Metal-binding sites include carboxyl, carbonyl, hydroxyl, phosphate and sulfhydryl groups present in cell walls and capsular polymers. It is difficult to resolve the relative contributions of these sites to the binding of a particular metal.
