CHARACTERIZATION OF SILVER NANOPARTICLES ISOLATED FROM BACILLUS CEREUS BACTERIA AND STUDY OF THEIR EFFECTIVENESS AGAINST BIOFILMS

Abstract

Silver nanoparticles were synthesized using the extracellular technique by utilizing the supernatant solution of Bacillus cereus bacterium, which was isolated from soil polluted with animal dung at farms located north of Basra city. The bacterial isolate demonstrated the capacity to produce silver nanoparticles, and its phenotypic and culture properties were analyzed. The study involves molecular diagnosis and characterization of silver nanoparticles through various techniques and devices. This is demonstrated by the observed color change in a reaction mixture containing 10 ml of 1 mM AgNO3 solution and 90 ml of the supernatant solution of bacteria. Specifically, the color of the reaction mixture transitions from yellow to brown, which is analyzed using a UV-visible spectrophotometer. The silver nanoparticles exhibited an absorption specifically at a wavelength of 430 nm. The EDX device achieved a purity of 70.50% for AgNPs. These silver nanoparticles were then utilized to hinder bacterial growth through the well diffusion method. Additionally, they demonstrated the capability to prevent biofilm formation in pathogenic bacterial isolates such as Pseudomonas aeruginosa, E. coli, Klebsiella pneumonia, and Staphylococcus aureus.