A Review on Use of Genetically Engineered Microorganisms for Bioremediation of Environmental Pollutants and Heavy Metals

Bioremediation refers to the use of organisms to remove environmental pollutants. Besides identifying different new plasmids capable of degrading environmental pollutants, many attempts have been taken by the genetic engineers to enhance the bioremediation potential of different microorganisms. Escherichia coli was engineered to convert chlorinated solvents such as trichloro ethylene and the highly toxic methyl parathion (pesticide), to non-toxic form. Escherichia coli was also engineered to remove radioactive waste (uranium) from environment through precipitation. Pseudomonas fluorescens, Escherichia coli and C. testosterone were engineered to degrade different Polychlorinated Biphenyls. Deinococcus geothermalis, Escherichia coli and Ralstonia eutropha were engineered for bioaccumulation of heavy metals to remove it from environment. Sinorhizobium meliloti and Escherichia coli were engineered for decolorization of azodye. Poly Aromatic Hydrocarbons and 2,4-dichlorophenoxyacetate (pesticide) degrading plasmids have been identified and transferred to indigenous bacteria of polluted soil through bioaugmentation which rendered them capable of degrading respective pollutant effectively.