Biosynthesis of Silver Nanoparticles by Food-Origin E. coli and Candida Species and Testing Its Antimicrobial Activity against Pathogenic Bacteria and Fungi

Due to the growing demand to improve an environmentally friendly, nonhazardous and cost-effective technology as a biocide to control the drug-resistant microorganism, thus in the present study; food-origin Escherichia coli, Candida zeylanoides and C. krusei were used for the biosynthesis of silver nanoparticles. The biosynthesis of silver nanoparticles was monitored upon the colour change of the reaction mixture by ultraviolet-visible spectroscopy. Furthermore, the product was explored by Atomic Force Microscopy; the results revealed the formation of silver nanoparticles in the reaction mixture of the used microorganisms. The biosynthesized silver nanoparticles from E. coli, C. zeylanoides and C. krusei showed a maximum absorption at 423 nm, 415 nm and 426 nm respectively at range between 300 to 800nm wavelength and the size was 64.93 nm, 102.86 nm and 95.37 nm respectively. The biosynthesized silver nanoparticles were tested for their antimicrobial activity against various pathogens Pseudomonas flourescence, Klebsiella pneumonia, E.coli, Candida guilliermondii, and C. albicans; the results showed that the silver nanoparticles that biosynthesized in the current research exhibited an effective antimicrobial activity.