Corallina mediterranea Extract-Mediated Selenium Nanoparticles as Effectual Antibacterial Agent Against Food-Borne Pathogens

Bacterial pathogens can acquire resistance to numerous antibiotics, necessitating the exploration of additional natural alternatives and nanomaterials as antimicrobials. The red seaweed Corallina mediterranea was extracted and its extract (CmE) was employed as mediator for synthesis of selenium nanoparticles (SeNPs). The CmE could effectually reduce and generate SeNPs, which had particles size range of 2.04-31.34 nm and mean diameter of 5.22 nm; they possessed high stability and non-aggregation attributes. The infrared analysis of CmE and algal-synthesized (phycosynthesized)-SeNPs appointed the potential responsible groups for NPs synthesis. The antibacterial activities of CmE, phycosynthesized SeNPs and their composites (CmE/SeNPs) wre proved (qualitatively/quantitatively) toward Staphylococcus aureus and Salmonella typhimurium. The composite (CmE/SeNPs) showed the highest activity, significantly (p < 0.05) surpassing the standard antibiotic (ampicillin) activity. Ultrastructure imaging of treated bacteria with the nanocomposites (CmE/SeNPs) elucidated their action , demonstrating their ability to destroy bacterial cells, deform them and result in bacterial death within 10 hours of exposure. The antioxidant activity of CmE/SeNPs was superior in scavenging DPPH, compared to CmE alone. Phycosynthesized SeNPs using CmE are recommended as effectual agents for combating and controlling bacterial pathogens, using natural and eco-friendly materials.