Biomimetic Synthesis of Silver Nanoparticles Using New Aquatic Species of Bacillus, Alcaligenes, and Paenibacillus and their Potential Antibiofilm Activity against Biofilm-Forming Escherichia coli

The current study aimed to assess the beneficial inhibitory effect of silver nanoparticles on biofilm formation by E. coli ATCC11922; eighteen Egyptian bacterial isolates obtained from Al-Bahr El-Pherony, Menoufyia Governorate were screened for silver nanoparticles biosynthesis (AgNPs). Three of the best extracellular AgNPs producing isolates have been identified using biochemical and molecular techniques. Characterization of AgNPs was performed by UV-visible spectroscopy, Fourier transforms infrared (FTIR), and Transmission Electron Microscopy (TEM). Next, the antibiofilm restriction of AgNPs was evaluated using the micro broth dilution method. A total of eleven bacterial isolates were positive for the AgNPs biosynthesis. Amongst, three AgNPs with tribute effects have the greatest anti-biofilm activity and have been identified as new species belonging to the genera Bacillus, Alcaligenes, and Paenibacillus. Plasmon surface resonance of the formed AgNPs had feature peaks at ~420 nm. FTIR confirmed the character of the capping/reducing agents of Ag+. X-ray diffraction and TEM investigation confirmed the purity, spherical shape, and size of 3.01-16.47 nm. Besides, biosynthetic AgNPs reduced biofilm growth, biomass, and density by 80-90% on a dose basis. Therefore, biosynthetic AgNPs are green antibiofilm against pathogenic microbes. This fact promotes its use as a convincing disinfectant for soiling water and depleting pollution.