Sustainable and Ecofriendly Nanoparticle Synthesis Using Microbial Strains Isolated From Heavy Metal Rich Industrial Effluent

Abstract

Heavy metals present in industrial effluent that are discharged into the environment can leach into water resources and adversely affect human health and ecosystems. Bacteria have evolved defensive mechanisms to counteract heavy metal toxicity. In this study, the concentrations of Cobalt (Co), Copper (Cu), Iron (Fe), Manganese (Mn) and Zinc (Zn) in titanium industry effluent were found to surpass the permissible limits set by three authentic standards for drinking water. Notably, the concentration of manganese exceeded the permissible limit by a staggering factor of 500 times followed by Co, Fe, Zn and Cu. Eight morphologically different bacteria and fungi were isolated from this effluent. The cell free supernatants of six out of these eight cultures produced heavy metal nanoparticles at room temperature over a period of upto 7 days. The presence of nanoparticles was verified by visible colour changes, UV-Vis spectroscopy and FT-IR analysis. The maximum absorption of the Fe, Co, Cu, Zn and Mn nanoparticles was in the UV range between 300 nm- 401 nm. Two of the nanoparticle producers were identified as Bacillus cereus and Curvularia sp by MALDI-ToF. Our research highlights the ecofriendly and sustainable approach to nanoparticle synthesis and creating value from industrial waste.