Construction of merB recombinant vector in order to bioremediation of organic mercury

Organic mercury is a sustainable form of mercury that enters the food chain of organisms and cause dangerous environmental hazards for natural ecosystem. Mercury stability and high cost conventional refining methods are disturbing factors. In this field, biological methods such as the use of bacteria or enzyme based for microbial remediation provided low-cost strategy and environmental lover of bioremediation. In this research, merB gene isolated from resistance bacteria by PCR technique by specific primers containing NcoI and NdeI restriction sites, so after amplification, it cut with restriction enzymes and after purification of gene, ligation was performed into PET28 a expression vector. PET28a+merB recombinant vector was transferred into E. coli strain TOP10 by heat shock. The recombinant bacteria were selected in kanamycin selective medium. The presence of gene in transformed bacteria was confirmed by PCR on plasmid and by enzymatic digestion. Results confirmed the accuracy of cloning of merB gene into this expression vector. In order to the expresse its protein, the recombinant vector was transferred into E. coli BL21 (DE3). Expression of the protein was confirmed by SDS-PAGE method. Finally, the growth of E.coli strain BL21 containing the recombinant vector with E coli BL21 bacteria including empty vector was measured by adding methyl mercury into the environment during 48 hours. Growth ability of E.coli containing the empty vector indicates lack of bacteria resistance to mercury, on the other hand; merB protein in transformed bacteria increased their resistance to methyl mercury in the environment. Therefore, bioremediation of organic mercury from pollutant environments could be possible by using this methodology.