 Consequently, the genetic engineering approaches are used to create the new strain of microbes (Genetically engineered microorganisms, GEMS) which have better catabolic potential than the wild type species for bioremediation.There are four major approaches to GEM development for the bioremediation application which include the modification of enzyme specificity and affinity, pathway construction and regulation, bioprocess development, monitoring and control and lastly, bio-affinity bio-receptor sensor application for chemical sensing, toxicity reduction and end point analysis.These allow the extensive use of genetically engineered microorganism.