title: Genetic basis and importance of metal resistant genes in bacteria for bioremediation of contaminated environments with toxic metal pollutants.
abstract: Metal pollution is one of the most persistent and complex environmental issues, causing threat to the ecosystem and human health. On exposure to several toxic metals such as arsenic, cadmium, chromium, copper, lead, and mercury, several bacteria has evolved with many metal-resistant genes as a means of their adaptation. These genes can be further exploited for bioremediation of the metal-contaminated environments. Many operon-clustered metal-resistant genes such as cadB, chrA, copAB, pbrA, merA, and NiCoT have been reported in bacterial systems for cadmium, chromium, copper, lead, mercury, and nickel resistance and detoxification, respectively. The field of environmental bioremediation has been ameliorated by exploiting diverse bacterial detoxification genes. Genetic engineering integrated with bioremediation assists in manipulation of bacterial genome which can enhance toxic metal detoxification that is not usually performed by normal bacteria. These techniques include genetic engineering with single genes or operons, pathway construction, and alternations of the sequences of existing genes. However, numerous facets of bacterial novel metal-resistant genes are yet to be explored for application in microbial bioremediation practices. This review describes the role of bacteria and their adaptive mechanisms for toxic metal detoxification and restoration of contaminated sites.
authors: Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, Odisha, 769 008, India. surajit@nitrkl.ac.in.
authors: Surajit
authors: S
authors: Das
authors: Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, Odisha, 769 008, India.
authors: Hirak R
authors: HR
authors: Dash
authors: Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, Odisha, 769 008, India.
authors: Jaya
authors: J
authors: Chakraborty
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D001151:Arsenic / Q000302:isolation & purification / Q000378:metabolism; D001419:Bacteria / Q000235:genetics* / Q000378:metabolism; D001673:Biodegradation, Environmental; D002104:Cadmium / Q000302:isolation & purification / Q000378:metabolism; D002857:Chromium / Q000302:isolation & purification / Q000378:metabolism; D003300:Copper / Q000302:isolation & purification / Q000378:metabolism; D004785:Environmental Pollutants / Q000302:isolation & purification / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005818:Genetic Engineering; D006801:Humans; D007854:Lead / Q000302:isolation & purification / Q000378:metabolism; D008628:Mercury / Q000302:isolation & purification / Q000378:metabolism; D009876:Operon
chemical_list: D004785:Environmental Pollutants; D002104:Cadmium; D002857:Chromium; D007854:Lead; D003300:Copper; D008628:Mercury; D001151:Arsenic
keywords: Bacterial diversity; Bioremediation; Gene manipulation; Metal resistance; Metal resistant genes