Toxicological Study of Zn and Cd metal nanoparticles on the Growth of Azotobacter chroococcum
S.C. Singh, R. Raghvendra, R. Gopal
Allahabad University, IN
Keywords: metal nanoparticles, toxicology, microbial activity
Abstract:Nanoscience and technology is fast growing field of science and technology now days. It provides large possibilities in different area such as energy harvesting, energy storing, chemical as well as biological sensing etc. As Nanoparticles have highly reactive surfaces compare to their bulk counterpart, they may create several toxicological effects on the microorganism and bacteria and may cause as weapons for ecological imbalance. Present study is toxicological study of Zn and cadmium colloidal nanoparticles solution on Azotobacter chroococcum bacteria found in the roots of leguminous crops. Colloidal solutions of Zn and Cd nanoparticles are synthesized by pulsed laser ablation of corresponding targets in the aqueous solution of 10 mM Sodium Dodacyl Sulphate (SDS). As synthesized colloidal solution were used for toxicological testing. Azotobacter chroococcum were isolated from the rhizosphere of the plant by soil dilution and plate count method of Timonin, while were purified by the methodology given by Aquilanti et al., in 2004. Molecular analysis was done by method given by Aquilanti et al. (2004). Bacteria were grown for 2-3 days on TSA. Crude template DNA was prepared by suspending two or three colonies in 500µl of sterilized ultrapure water collected by centrifugation, re-suspended in 100 µl of water, added with 100 µl of 10 mM Tris- HCl pH 8.2 and vortexed. Finally, 13 µl of 1 mg/ml proteinase K (Sigma Chemicals, USA) were added. After incubation at 550C for 2 h, cells undergone to lyses were pelleted by centrifugation and 2 µl of the supernant fluid were used for the PCR amplification. The cultured bacteria were treated with 0.5 ml, 1.0 ml and 1.5 ml colloidal solutions of Zn and Cd and were left for 24 hours after that UV-visible absorption photometry was used for study of growth. It was observed that in both the case of Zn and Cd growth is highly inhibited with the addition of nanoparticles.