Microbially synthesized nanoparticles and their applications in environmental clean-up

ABSTRACT Rapid urbanization and development of industries have led to the continuous addition of various wastes and hazardous chemicals into the environment, thus polluting it beyond limits. It is an issue of global concern as coming up with effective methods for remediation has become a challenge. The traditional methods for pollutant removal face serious drawbacks in terms of cost and generation of secondary pollutants, thus innovating simple and environment-friendly approaches becomes a priority. New technologies are being explored for the eradication of different contaminants, of which nanotechnology has shown immense potential. Biogenic nanoparticles are synthesized using different microbes and are further employed for the remediation of environmental pollutants. Complete degradation of Methylene Blue within 11 min and 98% degradation of Congo Red after 20 min were accomplished using gold nanoparticles, synthesized using cell-free extracts of Bacillus marisflavi in a recent study. Palladium nanoparticles, synthesized using Shewanella loihica PV-4 and Enterococcus faecalis, facilitated the complete reduction of toxic hexavalent chromium. This review focuses on microbe-mediated synthesis of nanomaterials and their prospect in the field of environmental remediation. GRAPHICAL ABSTRACT