Extracellular synthesis and characterization of nickel oxide nanoparticles from Microbacterium sp. MRS-1 towards bioremediation of nickel electroplating industrial effluent.

In the present study, a nickel resistant bacterium MRS-1 was isolated from nickel electroplating industrial effluent, capable of converting soluble NiSO4 into insoluble NiO nanoparticles and identified as Microbacterium sp. The formation of NiO nanoparticles in the form of pale green powder was observed on the bottom of the flask upon prolonged incubation of liquid nutrient medium containing high concentration of 2000ppm NiSO4. The properties of the produced NiO nanoparticles were characterized. NiO nanoparticles exhibited a maximum absorbance at 400nm. The NiO nanoparticles were 100-500nm in size with unique flower like structure. The elemental composition of the NiO nanoparticles was 44:39. The cells of MRS-1 were utilized for the treatment of nickel electroplating industrial effluent and showed nickel removal efficiency of 95%. Application of Microbacterium sp. MRS-1 would be a potential bacterium for bioremediation of nickel electroplating industrial waste water and simultaneous synthesis of NiO nanoparticles.