Green synthesis of metal nanoparticles loaded ultrasonic-assisted Spirulina platensis using algal extract and their antimicrobial activity

The synthesis of metal nanoparticles (NPs) loaded on the ultrasonic-assisted Spirulina platensis (MNPs/UASP) was investigated using the green synthesis method. The S. platensis algal extract was taken as a reducing agent. The formations of metal NPs were characterised using UV-visible spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy. The antimicrobial activity of different metal NPs demonstrated various inhibitory activities against one gram-positive bacteria (Staphylocicus aureus), four gram-negative bacteria (Klebsiella pneumonia, Proteus vulgaris, Pseudomonas aeruginosa and Escherichia coli) and one fungus (Aspergillus niger). Both CrNPs/UASP and ZnNPs/UASP show good antimicrobial activity when compared with other MNPs/UASP against microorganisms. This MNPs/UASP is effective in preventing and treating the microbial infection and water pollution in the environment.