Preparation and characterization of glucose-conjugated super-paramagnetic iron oxide nanoparticles (G-SPIONs) for removal of Edwardsiella tarda and Aeromonas hydrophila from water.

Abstract

The present research was conducted to prepare efficient G-SPIONs by co-precipitation to remove Edwardsiella tarda and Aeromonas hydrophila from the aqueous solution. The synthesized G-SPIONs were characterized by UV-Vis spectrophotometer, DLS, FEG-TEM, FT-IR, XRD, and VSM analysis. The results showed that the synthesized G-SPIONs had super-paramagnetic properties (58.31 emu/g) and spherical shape (16 ± 3nm). The antibacterial activity was assessed in sterilized distilled water at different G-SPIONs concentrations viz. 0, 1.5, 3, 6, 12, 24, 48, 120, and 240 mg/L against E. tarda and A. hydrophila with various bacterial loads viz. 1 × 103 , 1 × 104 , 1 × 105 , 1 × 106 , and 1 × 107 CFU/ml at different time intervals 15, 30, 45, and 60 min. At a lower bacterial load of E. tarda and A. hydrophila 1 × 103 -1 × 104 CFU/ml, 100% bacterial load was removed by 15 min exposure with NPs concentration 6-48 mg/L and 1.5-6mg/L, respectively. Cent percent bacterial removal was observed in both the bacterial species even at higher bacterial load (1 × 105 -1 × 107 CFU/ml) by increasing exposure time (15-60 min) and nanoparticle concentration as well (24-240 mg/L). At an initial bacterial load of E. tarda and A. hydrophila (1 × 103 -1 × 107 CFU/ml), the EC50 ranged between 0.01-6.51 mg/L and 0.02-3.84 mg/L, respectively, after 15-60 min exposure. Thus, it is concluded that the antibacterial effect of G-SPIONs depends on concentration and exposure time. Hence, G-SPIONs can be used as an antibacterial/biocidal agent to treat Edwardsiellosis and Aeromonosis disease in aquaculture. HIGHLIGHTS: The glucose-conjugated super-paramagnetic iron oxide nanoparticles (G-SPIONs) synthesized by rapid and high yield co-precipitation method shows bacterial removal efficiency against Edwardsiella tarda and Aeromonas hydrophila The bacterial removal efficiency of G-SPIONs depends on concentration and exposure time to both the bacterial species The 100% bacterial removal efficiency can be achieved even at the highest bacterial load (1 × 107 CFU/ml) against E. tarda and A. hydrophila after 45 and 30 min exposure Due to the high bacterial removal efficiency of G-SPIONs against E. tarda and A. hydrophila, it can be used for the treatment of Edwardsiellosis and Aeromonosis in fish.