Metal bioremediation by microorganisms

In general, metal ions are accumulated by microorganisms for maintenance of vital biological functions. However, not always microorganisms accumulate metals due to metabolic necessity. The process of metal accumulation by microorganisms can be divided into two steps. The first one involves metal adsorption around the cell envelope and is commonly a metabolism-independent process (biosorption). The second one is exclusively dependent on cell metabolism and involves active translocation of metals by microorganisms into the cell (bioaccumulation). The recent concerns on the metal uptake capability by microorganisms have prompted the development of new technologies for metal removal or recovery from waste waters.