Safety and Efficacy of Pseudomonas Exopolymer in Sequestration of Iron From Aqueous Environments

Abstract

The present study reports the iron binding characteristics and safety of an exopolymer (EBP) of an environmental isolate of Pseudomonas sp. The EBP was predominantly polysaccharide in composition with pyruvic and uronic acid residues. A prevalence of carboxyl and hydroxyl groups was observed in the Fourier-transform infrared spectroscopy (FTIR) results, while scanning electron microscopy (SEM) revealed a porous structure in a linear fashion with large number of grooves. The purified EBP was stable for over two months and exhibited rapid binding of iron (25mg/L) within 10 minutes at ambient temperature. X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDAX) analysis of iron challenged EBP suggested the involvement of carboxyl groups in potentiating iron removal. Both Langmuir and Freundlich adsorption isotherms depicted high iron removal capacity in comparison to reported biomasses or biopolymers. Cytotoxic effects were not observed upon challenging various doses of EBP in RAW 264.7 cell lines implying a strong possibility of application of the EBP.