The present study was aims to develop the mercury resistant bacteria from mercury sensitive
bacteria. The contaminated soil samples were collected from around the BHEL (Bharath Heavy Electrical
Limited), Tiruchirappalli. The isolation of bacteria from soil sample was done by nutrient agar plate method.
The isolated organisms present in nutrient agar medium containing Mercury (II) Chloride for identification of
mercury resistant and sensitive bacteria. A total of fifteen colonies were isolated from the polluted soil sample.
Among them colony number twelve showed better growth in high HgCl concentration, indicating the mercury 2
resisting capacity of Staphylococcus aureus identified by morphological and biochemical tests like IMVIC,
Triple Sugar ion, Catalase, Citrate Utilization, Coagulase, Oxidase, Starch Hydrolysis, Urease Hydrolysis. Out
of fifteen colonies, seventh colony shows no growth which was sensitive to mercury i.e. E. coli confirmed by
the presence of green metallic sheen observed in EMB plates. The plasmid DNA from Staphylococcus aureus
was isolated and transformed into mercury sensitive E. coli. After the transformation the sensitive E. coli get
mercury resistant capacity was confirmed by agarose gel electrophoresis.