Study the function of Halotolerant Micrococcus luteus in biological removal of zinc

Document Type : Research Paper



The rapid growth of industrial activity in recent decades, and non-obedience with environmental laws, along with discharging of contaminant wastewaters from petrochemical industries lead to increase of heavy metals into the environment. Biosorption is an effective technology for optimal removal of pollutants such as heavy metals from marine ecosystems. In the present study, the microorganism, resisted to zinc, was isolated from Persian Gulf sediments and indentified via biochemical tests. Then, the growth ability of indentified microorganism was investigated in different concentrations of zinc. Also, the effect of salinity on the growth of microorganism was studied and the optimal conditions for its growth were determined. Eventually, the potential of bacterium in removal of zinc was studied. Micrococcus luteus was isolated as a zinc-resistant bacterium and identified using biochemical tests and bacteriologic references. The mentioned bacterium was able to grow up to a high concentration of zinc (800mg/l). The results showed that the removal of zinc enhanced along with the increase of zinc concentration. The maximum removal (169±5.4 mg/l) was recorded in 200 mg/l concentration of zinc and the highest percentage of zinc biosorption (76%) was happened at a concentration of 50 mg/l after 150 min of incubation. The result showed that M .luteus was halotolerant and could grow in the wide range of salt concentrations.