Heavy metals are natural constituents of the environment, but indiscriminate use
for human purposes has altered their geochemical cycles and biochemical balance. This
results in excess release of heavy metals such as cadmium, copper, lead, nickel, zinc etc. into
natural resources like the soil and aquatic environments. Prolonged exposure and higher
accumulation of such heavy metals can have deleterious health effects on human life and
aquatic biota. The role of microorganisms and plants in biotransformation of heavy metals
into nontoxic forms is well-documented, and understanding the molecular mechanism of
metal accumulation has numerous biotechnological implications for bioremediation of