Green synthesis of silver nanoparticles using nisin and its antibacterial activity against Pseudomonas aeruginosa

Background: Green synthesized silver nanoparticles (AgNPs) have been used in a wide range of biological applications, including their use as antimicrobial agents. The aim of this study was to evaluate the antibacterial activity of green synthesis AgNPs using nisin against Pseudomonas aeruginosa (P. aeruginosa). Materials and Methods: In order to synthesize Ag-nisin, a 1 mg/ml nisin solution was mixed with a 1-mM silver nitrate solution and incubated. The Fourier transform infrared spectroscopy (FTIR) analysis was employed to determine the presence of various biomolecules around AgNPs. The AgNPs were morphologically observed and characterized using field emission scanning electron microscopy assessment, dynamic light scattering (DLS), and zeta potential analysis. The microdilution broth method based on CLSI principles was used for the assessment of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of nisin on P. aeruginosa isolates. Results: Field emission scanning electron microscope showed spherical shaped nanoparticles. DLS revealed that the average size of nanoparticles was 37.2 nm. The zeta potential of AgNPs was - 13.3 mV. FTIR findings revealed that nitrogen atoms of nisin's amine and amide groups are responsible for the capping and stability of the nanoparticles. The MIC and MBC showed that Ag/nisin nanoparticles had higher antimicrobial activity than nisin or AgNPs alone. Conclusion: The findings of this study show that the antibacterial activity of nisin can be increased by assembling it into the AgNP interface using a green chemical synthesis method. As a result, the technique may be used to develop an antibacterial formulation to enhance the effectiveness of nisin.