Antibacterial Activity of Various ZnO Nanostructures on Pathogenic Bacteria Found in Selaiyur Lake, Tamil Nadu

Water is the elixir of life and globally the imperative need of the hour is uncontaminated water. Water has a great impact on every aspect of human life and with increasing environmental pollution and rapid growth of population, the need for developing technologies to remove pathogenic bacteria from the water bodies has become inevitable. This research aims to study the effect of synthesized ZnO nanostructures on a few very common gram-positive and gram-negative bacteria like Klebsiella, Staphylococcus, Proteus and Bacillus found in Selaiyur Lake, Tambaram, Tamil Nadu. Zinc oxide nanoparticles used for the anti-bacterial study were synthesized by dry mechano- chemical and sol-gel methods. The SEM images of the samples show formation of spherical, flower shaped, nut shaped and hexagonal disc shaped nanostructures. The XRD analyses show the formation of pure hexagonal wurtzite crystalline structures. The particle sizes of the synthesized samples were found to be in range of 15- 90 nm. The Lake water samples taken for studies underwent serial dilution using saline solution under sterile conditions. By the method of spread plate the bacterial colonies are observed. The experimental results show that the synthesized zinc oxide nanoparticles have appreciable antibacterial properties. Using the gram stain test, both gram-positive and gram-negative bacteria were found in the sample. The nanoparticles were found to be resistant against both types of bacteria. The spherical nanostructures with ZnO nanoparticles of 16-19 nm sizes synthesized by dry- mechano chemical method was found to be more effective against all the four types of bacteria studied. The size and surface morphology effect of ZnO nanostructures on bacterial growth was also studied in comparison with commercial Bulk ZnO nanopowder.