Green fabrication of iron oxide nanoparticles using grey mangrove Avicennia marina for antibiofilm activity and in vitro toxicity

The aim of the present study is a biogenic synthesis of iron oxide nanoparticles (FeO-NPs) using grey mangrove Avicennia marina to control marine and pathogenic biofilm forming bacteria. Initially, the synthesized nanoparticles were characterized by UV-visible spectrometer, scanning electron microscope and transmission electron microscope for size and shape, Edax analysis for elemental confirmation, zeta potential for stability, X-ray diffraction for structure and Fourier transform infrared spectroscopy for functional group analysis. Further, the antibiofilm activity of FeO-NPs were inhibited the initial attachment and biofilm development of primary biofilm forming bacterial strains Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Almost 72% of quorum sensing factors of P. aeruginosa were impeded by 200 mu g/ml of FeO-NPs, 63% and 46% for S. aureus and E. coli respectively. The FeO-NPs also decrease the cell surface hydrophobicity of E. coli, P. aeruginosa and S. aureus from 16% to 9%, 19% to 11% and 15% to 11% respectively. Moreover, the FeO-NPs inhibit the production of exopolysaccharide in E. coli, P. aeruginosa and S. aureus from 90% to 69%, 92% to 65% and 86% to 60% respectively. Further, the FeO-NPs also showed less toxicity against human HBL100 cells using the MTT assay. In conclusion, the biogenic FeO-NPs could be used as a potential antibiofilm agent against marine and medical pathogenic biofilm forming bacteria.